Old Production Takes From an Old Guy

Tag: rechargeable (Page 1 of 2)

Choose the Blue Pill…er, Battery

If you’ve been around ChurchTechArts for any length of time, you know I’m a big rechargeable battery fan. I placed my first order with Horizon Battery in July of 2006 for ten 250 mAh 9V batteries and a charger. I was a new, part-time TD and saw how much money we had in the budget for batteries. I knew there had to be a better way, and had seen their ad in Church Production. I figured, why not give it a shot. And I was hooked.

Since then, I’ve personally ordered hundreds of batteries and dozens of chargers. I’ve tested, and used them exclusively for wireless mic’s, flashlights, keyboards, mice and Magic Trackpads for the last seven years (long before Horizon was a sponsor). I say all that to make the point that I’m not just a shill for the company. And while they do spot me a few things here and there, I pay for 95% of all my batteries. 

With that out of the way, I wanted to update you on the state of rechargeable batteries. I’ve been receiving a few reports of late from people who have had trouble with the new batteries fitting in their mic’s, and even damaging battery trays. We ran into the same issue. A while back, Ansmann released these new batteries:



Stay away from these for Shure mic's. They fit OK in Sennheiser, and you'll have to test them in other brands. Or just get the Slimline versions (below)

Stay away from these for Shure mic’s. They fit OK in Sennheiser, and you’ll have to test them in other brands. Or just get the Slimline versions (below)

They are the same 2850 mAh capacity AA cells we’re used to, but for some reason, they are a little bigger around than the old blue or shiny silver ones we once got. I believe this has to do with new European regulations for rating the batteries, but we have seen issues with them fitting. They are very tight in a Shure UR2 handheld, and they really don’t work well at all in UR1 body packs or PSM wireless in ear packs. 

Unfortunately, like a lot of you, I didn’t notice this until I ordered a whole set of them. I also didn’t notice that the Slimline version has been re-issued. It looks like this:



For Shure mic's, body packs and PSM receivers, you'll want to use these.

For Shure mic’s, body packs and PSM receivers, you’ll want to use these.

I ordered a set of these and found they work perfectly in all the Shure products—including the PSM packs we had big problems with using the dull silver versions. So, if you’re going to be ordering new batteries anytime soon, make sure you get the Slimline version in the blue wrapping. The good news is that they are the same price, and the same rated capacity. Why not just offer these and not the other ones? As I said, it has to do with the way the batteries are rated, and apparently, the blue ones may not have quite the actual capacity of the new ones. But they do fit better, and the runtime is still far more than adequate (we got almost 14 hours in our test).

I did find that the “full-size” dull silver batteries work fine in Sennheiser G3 handhelds and body packs. So I’m re-deploying my dull silver cells throughout the church in our kids and student rooms where they will work just fine. 

So if you’re a Shure house I recommend buying the blue, Slimline version if you’re ordering; that will ensure they will fit in whatever mic you need to use them for. If you just bought a bunch of new, silver ones, this might be frustrating, but keep in mind, if you were using alkaline batteries, you would buy them, use them and throw them away. At least you can use the dull silver ones in your mice, keyboards and other mic’s. 

If you’re curious about rechargeable batteries and are new to the subject (or have a bad taste in your mouth from being burned with the bad ones of old…) you can see my comprehensive reporting of the subject here: Rechargeable Batteries

Oh, and if you happen to need any AAA cells, you should order up some of the new 1100 mAh versions. Again, due to the new ratings, we have found these to last far longer (in runtime) than the old 1000 mAh AAAs, at least in our UR-1M. Apparently, to be called an 1100 mAh, they actually have to be closer to that, whereas the old 1000 mAh versions were more like 750-800. So it’s a big upgrade. And they fit fine.

Today’s post is brought to you by GearTechs. Technology for Worship is what they do. Audio, video and lighting; if it’s part of your worship service, and it has to do with technology, GearTechs can probably help. Great products, great advice, GearTechs.

Extending Rechargeable Battery Life

UPDATE 1-21-13: Having tried turning our chargers on and off out for about 6 months, I’m not convinced it helped us extend the life of our cells. In fact, it may have shortened them. I’ll leave this post online for those interested in the process, and I still think rotating them is a good idea. The timer power strip, however has been put to another use. END UPDATE

Though I’ve been using rechargeable batteries for almost 6 years now, I’m still learning the best way to maximize their life and run time. I am a firm believer in continuing education, and we try to monitor the life of our batteries, look at the data and feed that information back into our systems that get tweaked for better performance. 

As I said in my previous post about batteries, I was a little disappointed in the life I got of my first set of AAs. I don’t blame the manufacturer; I suspect we didn’t use them in a way to maximize their life. So we’ve made a few changes. These changes are based on our usage patterns, so consider them as principles we’re trying, not absolutes to follow.

Rotate

The first thing I did was to establish a rotation pattern for our batteries. We have 32 AAs in stock, and use 12-16 for a normal weekend. However, now that I have a team of volunteers who help set up on Saturday (and this includes getting batteries for the mic’s), I noticed that they would gravitate toward some of the chargers and leave the batteries on the other ones. I suspect this led to some of the batteries being used a lot more often than others. This would explain why I have 12 or so batteries from the original set that still work great, and others that are pretty much done for.

Based on our usage, I designated two chargers (they hold 8 batteries each) as Saturday and two as Sunday. That way, everyone always grabs the batteries out of the right chargers, and we don’t end up using the same ones for the whole weekend. To further randomize the rotation—and because we sometimes have to dip into the other set to accommodate all the mic’s, or because we don’t use them all—when I charge my AAAs for the stand lights, I pull all the AAs out, put them in a box, and randomly put them back in the chargers.

My theory is that this will average out the usage patterns for all the batteries to be roughly equal. While the Saturday on time is a little longer than Sunday, the fact that they get mixed up and put back in different day’s chargers should even that out.

Timing the Charging

My friend Dave Stagl pointed me in this direction; a timed power strip to turn on and off the chargers so they’re not sitting there trickling all week. A the time, it sounded like a good idea. As I’ve done more research, that is confirmed. It seems that NiMh batteries don’t like to be on a trickle charge all the time, as that can lead to over charging, or just lazy batteries. It is recommended to charge them, take them off the charger, then top them off before use. While I could do that, it’s a lot of work—and you know how much I like to automate things.

This power strip, made by GE and available at Amazon or your local home center, costs about $30. It can be programmed for seven days, which would be great if you had a mid-week service or rehearsal that you needed the batteries topped off for.

Enter the timed power strip. By setting the power strip to turn on at 5 PM on Friday and off at 5 PM Sunday, I have fully topped off batteries for the weekend, they fully top off on Sunday afternoon, then rest during the week. Of course it’s too soon to tell how this will extend the life, but based on my research, I’m hopeful.

Keep Refining

In the past, I recommended leaving the batteries on the charger all the time. I’m changing that stance based on new information and experience. This is not back-peddling or being wishy-washy; I’m simply committed to finding better ways to do everything. As new information becomes available, I update my position. I think that’s healthy.

Also, if you’re interested in learning more about rechargeable batteries, I encourage you to check out Battery University. There is a wealth (and I mean a wealth) of information there about battery technology, chemistry, charging, discharging, etc. It’s pretty impressive, really. And a hat tip to reader, Frank Dengel for making me aware of this resource. 

This post is brought to you by Horizon Battery, distributor of Ansmann rechargeable batteries and battery chargers. Used worldwide by Cirque du Soleil and over 25,000 schools, churches, theaters, and broadcast companies. We offer a free rechargeable evaluation for any church desiring to switch to money-saving,  planet-saving rechargeables. Tested and recommended by leading wireless mic manufacturers and tech directors. 

Rechargeable Batteries: Year 2


Battery-graph-1-year-later.jpg

These were the results of the 1-year test.

OK, the title of this post might be a little misleading. I had actually indented to do multi-year tests to see how the rechargeable batteries in heavy rotation would hold up over the years. However, the answer is this; not quite as well as I had hoped. In fact, we got about 22 months out of the batteries before they were not performing to level that I was comfortable with. To be fair, some of the batteries are still going strong, but others have thrown in the towel. So I’ve replaced my entire stock.

And right away, all the naysayers will jump in and say, “Ha! I told you rechargeables were a bad idea!” Not so fast, cowboy. I’ll come back to that in a minute; first let me lay out the timeline. 

In January of 2010, I started buying chargers and batteries. By March, we had switched over completely to rechargeable batteries, which is also when I did my first round of tests. Those batteries were used every weekend and at mid-week, and as a group, performed exceptionally well. We did have one or two cells go bad, and those were replaced. Those cells got us through Easter, Christmas, and another Easter, not to mention outside events and other special services. 

Last fall, I started noticing that some of the cells began to drop off in capacity. I never had a mic die during a service, but I started seeing them drop down lower than I was comfortable with. Some batteries would end the second service on Sunday at 1 bar, which I didn’t like. I marked those batteries, tried re-conditioning them, but eventually decided that it was time to replace them. So in late November, I ordered a new set of 32 batteries and retired the old ones. 

Now, let’s do some math. We used the original batteries for about 22 months. We used to go through approximately 36 ProCells a week between weekends and mid-week. So here’s how it breaks down:

22 Months = 95 Weekends/Mid-Week (weeks)

95 Weeks x 36 batteries/week = 3,420 Batteries (if we used ProCells)

3,420 batteries x $0.32/ea = $1,094.40

So, if we had stuck with ProCells, we would have used roughly $1,000 worth of disposable batteries in that time frame. When I bought new batteries in November, I spent about $120 including shipping. Now it’s true I do have a few hundred dollars in charger cost, plus the original set of batteries. But on the high side, I’ve spent less than $500 on everything including chargers in the last 2 years. And now that the chargers are paid for, I can plan on about $120 in new batteries every two budget years.

But wait, there’s more! We also use AAA powered LED music stand lights every week. We have about a dozen of them in rotation, and we typically use about 6 on any given weekend. Those take 3 AAAs apiece. I also switched those over to rechargeable batteries about the same time. Only with those, I use low self-discharge (Ansmann Max-E) batteries so they don’t need to live on the charger all week. Let’s do some more math.

6 Stand Lights/week x 3 AAAs x 95 weeks = 1,710 AAA batteries

1,710 AAAs x $0.39 = $666.90 (I knew disposables were evil!)

Now there’s another $550 or so in savings (I have about $100 in Max-E AAAs). And those batteries are still going strong. I found that I can get about 3 weekends worth of service from those batteries in those lights. So, every three weeks, I pull my AAs out of the chargers, and charge up the AAAs. It takes about 10 minutes of my time, and we save $500/year. Not too bad. 

And this doesn’t count the community room, which I’ve also switched to rechargeable batteries. There is an event using a wireless mic over there almost every day, and they are on the same set of batteries they’ve had for nearly two years. Because the event times are shorter, a decrease in run time hasn’t been as big of a deal. Still, I may have to drop another $25 and get a new set of 8 AAs over there in the next month or so.

Earlier I mentioned that the performance was dropping off past where I was comfortable. I’m often asked, “When do you replace the rechargeable batteries?” The answer for me is, when I’m not comfortable any more. If I start seeing the cells drop down below 2 bars regularly after a service (when they used to hold at 4), it’s time to swap them out. Basically I’m replacing my rechargeable batteries when their weekly performance drops just below the level of a ProCell. 

How long that takes for you will depend on how you use them. I know people who use them far more often than I do, who will have to replace them more often, but when you do the math, you still come out way ahead.

Remember, those ProCells were going in the trash when they got down to 2-3 bars. With a rechargeable, you throw it on the charger. So it still works out. 

If you’re still on the fence, I encourage you to do the math. Figure out what you are really using now, and what the payback is. I can almost guarantee you the result will be savings when you switch. And we already know that rechargeables in good condition will outlast ProCells anyway by 30-50% and at end of life they are still on par; so there is really nothing to loose.

Next week, I’ll share my current strategies for (hopefully) lengthening the life of my rechargeable batteries.

Have you made the switch yet? If so, what is your experience? If not, what are you waiting for?

Today’s post is brought to you by Elite Core Audio. Elite Core Audio features a premium USA built 16 channel personal monitor mixing system built for the rigors of the road. For Personal Mixing Systems, Snakes, and Cases, visit Elite Core Audio.

Rechargeable Batteries: The 1 Year Test

Last year, I wrote a series on rechargeable batteries. I’ve long been a proponent of them, having started using them in wireless mics in 2006. In that series of posts, I did some pretty extensive testing to see exactly how long two modern, NiMh AA batteries would run a Shure UHF-R mic with an SM58 capsule on it (with music played through a wedge to simulate the mic processing audio). I compared the run time to a brand new Duracell ProCell (considered the standard for alkaline–aka disposable–batteries). I expected the NiMh batteries to hold their own against the ProCell, as I’ve had good experience with them for years. What I did not expect is for the ProCells to be completely trounced by the rechargeable cells.

In that test, the best NiMh cells ran for 14 hours before the mic switched off. The ProCell only managed 9.75 hours before going dead. So not only do rechargeable batteries save you a bunch of money, they also run longer than a ProCell (by over 4 hours!). Faced with that clear and decisive victory, many people made the switch. However, some remained unconvinced. “Let’s see how they hold up in a year,” was a comment I heard often. So here we are, one year later. This time, I pulled three sets of NiMh batteries from our regular stock. These are batteries we’ve been using every week for a year. I have no idea how many cycles are on each one, because we have more stock than we actually need. I can tell you we don’t baby them, nor do we abuse them. They’ve always been charged at the soft charge setting (500 mah), and we always pull straight from the charger.

Last time around, I tested two low self-discharge chemistries, the Ansmann Max-E and the Sanyo Eneloop. Neither provided the runtime of the higher capacity NiMh batteries, but they both outlasted the ProCell. As I don’t see any compelling reason to use low self-discharge batteries in wireless mics, I’ve pulled them from our stock and didn’t re-test. I have the charger capacity to always fill mics from the charger and suggest that to everyone. I do use Eneloops at home, however, and they’re fantastic. But let’s get on to the results, shall we?

UPDATE 3/18/11:

It was pointed out that I did not include model numbers for the batteries in question. So here goes: Ansmann 2850 mAh, PowerEx 2700 mAh, Sanyo 2700 mAh. All are NiMh chemistry.

END UPDATE.

Battery Testing Graph

I think this speaks for itself. Click for a larger version

Results

As you can see from the chart, the ProCells once again lost. Big time. This time, we got 8.5 hours out of a fresh set of ProCells, while the worst NiMh battery ran over 12.5 hours. Just as importantly, the “fall off the cliff” point (as indicate by the vertical red lines) is 7 hours for the ProCell and 11.25 hours for all three NiMh batteries. I define “fall off the cliff” as the point where you really should replace the battery as the life declines very rapidly after this point. Interestingly, last year, the Sanyo ran the longest at 14 hours (beating the Ansmann by 45 minutes); this year however, the tables turned and the Ansmann outlasted Sanyo by well over an hour.

It’s also interesting that all three NiMh batteries fall off the cliff at roughly the same point, however the Ansmann lands a little softer, giving you a little more time to get them changed. Now, with that said, quibbling over the last hour of run time in the scope of a total run time of 14 hours is rather academic. And I don’t recommend you push them this far anyway, you’re really asking for trouble after about 8-9 hours with any of them. Again, it’s interesting to note that the Ansmann indicated 3 bars far longer than the rest of them, which is consistent to what we observe each weekend.

In Use

In our use, we battery up the mics around 12:30 on Saturday, and power them off at 6:45 or so. Most of the time, the mics are reading 3 bars, though the Ansmanns tend to be reading 4 at that point. When we use them in our PSM900 IEMs, we rarely see them report less than 4 at the end of the day. Sundays are similar, though the runtime is shorter.

We’ve gotten pretty confident in the run time of these batteries; to the point where we really don’t spend much time thinking about it. Sure, I have Workbench open at FOH and glance over occasionally, but it’s more to make sure they’re all turned on; I rarely consider the battery gauge. For me, that’s a big benefit of using the rechargeable batteries; I just don’t think about them anymore. When I’m at FOH, I’d much rather spend my time thinking about the mix than wondering whether my batteries are going to hold out for one more song (and I’ve been in that boat far too many times with ProCells).

Other Observations

Last time around, I gave the nod to PowerEx batteries as the winner, though I acknowledged the other two as being so close that it really doesn’t matter. A year of use has changed my mind. We have a bunch of all three batteries, but we use the Ansmann more than the others most of the time. This is for a few reasons. First, the Sanyos are bigger than the others and don’t fit well in the UR2s. We have to pull them out, and that’s caused some degradation of the plastic wrap on the outside. Some of them are really coming apart. The PowerEx are also breaking down a little bit, and again are slightly bigger than the Ansmanns. They come out of the mics better than the Sanyos, but the smaller Ansmanns fit the best. Overall, the Ansmann cells are holding up very well, both in charge capacity and physically. We have had two Ansmann batteries short out internally, however. I’m not sure what caused this; the vocalist noticed the mic heating up, so we pulled the cells and found a clear dark line on the top of the cell. This happened twice in the first 6 months of operation, and hasn’t been repeated. We assume we got a few bad cells, because I’ve used at least 150 Ansmann batteries over the years and these are only two to ever go bad.

As I’ve said over and over, we’re saving a ton of money every year on batteries; at least $1,000 and probably more. Given that it cost us less than $300 to get into it, it’s a pretty fair bargain. I expect the batteries to last 5 years before we have to replace them, our savings is pretty significant. It’s also considerably more environmentally friendly to not dump thousands of used AAs in the trash every year. We use them and don’t think about it, which I really like.

I’m not sure how you could remain unconvinced about the effectiveness of rechargeable batteries at this point, but in case you are, we’ll revisit these same cells a year from now and see how they’re doing. Until then, I’m going to find something else to spend that $1,000 on. Maybe some new mics…

Rechargeable Batteries—After the Switch

Almost six months ago we made the switch to rechargeable batteries. Next month, I’ll be doing some follow up tests to see how well the battery capacity is holding up, but for this post, I thought I’d share some thoughts on how our process has been working out.

To recap, we have stopped using alkaline batteries almost completely. I say almost because I still have a few around for the odd guitar player with a dead 9v (ProTip: If your guitar takes a battery, have an extra one or three in your case, OK?), or for the occasional metronome or other device that shows up on stage unexpectedly. However, for our regular production equipment, we’re completely rechargeable.

We went with a variety of batteries in our system. For the lead pastor’s UR1M, we have two sets of Powerex AAA batteries. Those live in a dedicated 4 cell charger that charges them nice and slowly. There has yet to be a time when the “fuel gauge” on that mic drops below 4 of 5 bars on a weekend. I have a set of eight Ansmann, a set of eight Sanyo and two sets of eight Powerex cells for our UR1s and UR2s, as well as the PSM900 receiver. The AAs get more run time on a typical weekend than do the AAAs, but we’ve never had one drop down below 3 bars. I also bought a bunch of Powerex Imedions for use in our MightyBrite music stand lights. Those are LED-based lights, so the power draw is quite low. The Imedion is a 800 mah, low self-discharge design. I’ve found we can easily get three weekends of stand light use out of them before needing a recharge. We could probably go four, but if we use the same stand lights every weekend, they tend to start getting a bit dim on weekend four. Since it really doesn’t cost anything to recharge them, we do.

We’ve established a really straight-forward process for managing the batteries. I have the capacity to charge 24 AAs at once, so we leave 24 batteries on trickle charge all week. Come Saturday afternoon when we’re setting the stage, we’ll pull batteries out of the charger and load up the mics. Depending on the weekend, we’ll use between 10-18 cells. Saturday night, the monitor engineer collects the mics (and the PSM900) and puts the batteries back in the charger. We always charge using the soft charge mode, which charges at a rate of 500 mah. Sunday morning, we repeat the process. With Alkaline batteries, we would typically try to stretch the batteries for a full weekend (though, they often didn’t make it). With our current process, we may have added a few minutes worth of battery change time to our weekend routine.

For the Imedions, I have a recurring task set up in my Associate TD’s to do list every three weeks. All told, it takes about 10-15 minutes to cycle the batteries out of the lights, into the chargers and back. Since that’s only once every 3 weeks, it’s not a big cost. I have more Imedions than we actually use, so if someone leaves a light on overnight, we’re not in trouble.

A Few Observations

As expected, the batteries are working very well. In the past six months, we’ve not had a single mic go out due to batteries. In fact, none have even been close. We have Wireless Workbench set up at FOH to monitor the health of the packs, and it’s gotten to the point where I don’t even think about them anymore.

One thing we have noticed is that the AAs are a little bigger around than Alkaline cells, and that diameter varies between brands. Ansmann are the smallest, followed by Sanyo, then Powerex. The Powerex are a really tight fit in the UR1 bodypacks, and I’ve taken to using Ansmanns in those. In the UR2 handhelds, all of the cells fit, but removing the Powerex cells takes a bit of creativity. I’ve found if you pull the exposed battery out quickly, the force of the spring is enough to eject the other one enough to remove it. Go slow and you’ve got your work cut out for you.

After six months of heavy use, that’s about the only drawback we’ve found to them. Given that we’ve kept over 600 AAs and AAAs out of the landfill and saved over $250 in that time, I feel pretty good about the switch.

As I said, next month I’ll be re-testing the batteries I tested in March and we’ll see exactly how well they’re holding up. From a practical standpoint however, it’s been a great success.

Rechargeable Batteries—Making the Switch

After the last post on batteries, Dave asked a really good question: How does one get started? Other questions were raised as well;  How to you justify the cost of the charging infrastructure? How do you determine charging/cell capacity? Good questions, all and I will attempt some answers. First, some history.

When I first started using rechargeable batteries, we were using 8-10 wireless mics on stage every week. So, I bought 20 charging slots and 40 batteries. I figured I wanted to have enough slots and cells on hand to have a complete set charging at all times. We then changed our batteries between rehearsal and Saturday night service, and between the two Sunday services. That worked well, and we never had a battery go down on us, save the times we forgot to change them. That was also using a 9v infrastructure. I think my initial investment there was a bit over $300, which was a huge savings considering we were spending $20/week on disposables.

Fast forward to today. We are now running 6-8 wireless mics a weekend, all using AAs except our pastor’s UR1M which uses AAAs. I just placed an order with Thomas Distributing for three Maha MH-C800S chargers with 8 slots each. That gives me the capacity to charge 24 batteries at once. Total cost $171. I will have 32 AAs and 4AAAs in stock. That quantity of AAs will set you back about $108. So total investment is about $280. We spend between $300-500 on disposable batteries per year, so the cost is easily justified. I expect to replace the rechargeable cells in 3-5 years at a cost of another $108. Over 5 years, we come out at least $1,300-1,500 positive. So for me, the initial cost is a complete no-brainer. Here’s how I arrived at the counts.

Based on my current testing, I am completely confident that my rechargeable cells will easily get me through Saturday rehearsal and service (about 4.5 hours of power-on time) and Sunday run-through and services (about 5 hours of power-on time). All the NiMh cells I used ran for well over 13 hours in my testing, so even if they lose 50% of capacity over 5 years (which I don’t expect), they will still be working well. Since my 4-year old Ansmann ran almost as long as the new ones, I’m not too worried.

So, given our normal usage, up to 8 wireless mics, that makes for 16 cells. A few times a year, we’ll have 12-16 wireless mics on stage, so I spent an extra $57 on a third charger. Really, I don’t need it, but for $60, I figured why not. With 32 cells on hand, I can have one complete set in use, and  almost one complete set charging at all times, even under our most extreme conditions (I also have another 8-cell charger in our student room that I would appropriate during big productions, so I could charge them all). My strategy for making the switch was to go all in. When I did the math, it is an easy investment. However, if I were going to dip my toe in the water, here’s what I would do.

Start with a single 8-bay charger ($57) and 8 batteries ($26). That equals $83 and you’re in. Try those batteries on 4 of your wireless mics. Do some tests, find out how long they run. I know the UHF-R are pretty efficient, but I would expect most mics that use AAs to run at least 10 hours on the Powerex, Ansmann or Sanyo 2700 batteries.

Because the batteries will easily last through 2-3 services, put them in when you start and charge them when you’re done. Always go straight from charger to mic, and back again. Since you’re charging through the week, use soft-charge mode (500 mAh) and the batteries will last a long, long time. As you get comfortable with them, double your inventory of chargers and cells. With 16 bays of charging and 16 cells, you can run 8 mics all weekend, even if you do Saturday services. That will set you back just over $160 total, and will eliminate the need for almost all disposable batteries in most churches. If you don’t feel you can justify the additional cost for another charger for big events, stock up on some ProCells for that. However, for a big event, you’ll probably spend $40-50 for ProCells anyway, so why not just buy another charger instead?

Anymore, the cost of entry is so low, it’s hard to justify not getting started. I was looking back through our battery invoices of the previous 3 years the other day and saw bills for $70, $140, $70, $300, $140 over and over and over again. Since we paid that much for something we threw away, the cost to buy something we can use over and over again is an easy decision.

Now, you could spend a lot more money and buy one of Ansmann’s super-cool rack mounted chargers. These babies will charge 16 batteries at once. And they will set you back over $500. Honeslty, I don’t think the cost is justified. I’ve used those chargers and they’re great (except the tabs on the charging trays that don’t always lock in, giving you two uncharged batteries). But I can buy a lot of $60 chargers for $500.

The Maha MH-C800SAlso, if you look on Thomas Distribution’s website, you’ll see Maha has two models of the 800 series. The MH-C801D model will charge at 1000 mAh or 2000 mAh, which means you could fully charge a 2700 mAh battery in just over an hour. That sounds great, but in reality, we don’t need that kind of turnover, and it’s a lot tougher on the cell. I go for the MH-C800S model, which is not only cheaper, has a 500 mAh slow charge mode. Because we’re only using 50% or so of capacity anyway, it still only takes a few hours to fully charge them; and it’s a lot easier on the cell. Easier charging equals longer life.

Now, if you use a dozen or two wireless mics every weekend, the initial cost is going to be higher. However, keep in mind you’re spending the money anyway. So again, the way to do it is incrementally. Every time you get ready to place a battery order, instead of sending $100 to Duracell, buy a charger and some NiMh cells. Over a period of a few months, you’ll be fully rechargeable.

I used to say it takes a little more work to use rechargeable batteries, but I don’t think it does any more. I put the batteries in and forget about them until we’re done. Pop them into the charger and go home. I won’t be changing them between services any longer because I don’t need to. And since I’m not trying to stretch ProCells all the way to the end (to try to save money), I don’t need to keep a close eye on the battery level meters.

So that’s how I would do it. The cost of entry is now so low, it’s hard to justify not diving in. And if you really want to do it on the cheap, you could get a 4 cell charger for $25 and spend under $37 to try them out. I have a 4-cell charger that Thomas Distributing gave me for the testing and I’ll be using it for my AAA inventory. It soft-charges at 300 mAh which should keep my AAA cells (rated at 1000 mAh) happy for a long time, so you’re investment won’t be wasted. Like I tell people all the time, “It’s just math.” Do the math and see where you come out. I think you’ll find it’s not a hard decision.

Rechargeable 9v Batteries—Q&A

Several people have asked if I will be testing and reviewing 9v rechargeable batteries anytime soon. The short answer is no. I only have one device (a PSM600) that uses 9v right now, and hope to replace that by summer. Still, I’ve used a lot of 9v batteries in the past, so I’ll put up some thoughts and recommendations here.

First, I’ve had great success with Ansmann 250 mAh 9v batteries and chargers. I’ve used the 9v cells in ULX mics from Shure as well as PSM600s and PSM700s. Run time was always more than two services, and as long as we changed them regularly, they never failed us. The batteries themselves lasted a long time; I have 2 churches worth of experience at 2 years each. Given how expensive a disposable 9v is, the payback period is short.

UPDATE 10/6/13: Ansmann now makes a 300 mAh 9v battery, which I would recommend over the 250 mAh version. Horizon Battery also carries a 600 mAh LiOn battery from HiTech. According to reports, this battery will run 12-15 hours. You must use their charger, however, so be aware of that. Still, it looks like a great option if you are still running 9v batteries. END UPDATE

The question was raised about capacity of 9v batteries, and how they appear to be much less than a AA. Simply looking at mAh ratings does not tell the whole story; we need to look at energy capacity, and for that we need to convert to watts (or in this case, milliwatts). Take a 9v 250 mAh battery. The actual voltage is 8.4 volts. We know that Volts x Amps = Watts, so, 8.4 x 250 = 2,100 mW. In contrast, a AA rated at 2700 mAh works out this way: 1.2 x 2700 = 3,240.

So while it’s true that a AA cell has significantly higher energy density (which is why most mics are heading to AAs…), the 9v is not too shabby.

I’ve also use the 300 mAh Powerex batteries from Maha with great success. Do that math on those and you end up with 2,520 mW. iPower also makes a LiPolymer 9v rated at 500 mAh, which gives you over 4,000 mW. So the capacity is there—just know that run times will be a little shorter with the lower power batteries.

If you only need a few 9v batteries, look at the Maha MH-C490F. It’s a 4 position charger and runs about $30. For higher capacity, look at Maha’s MH-C1090F (8 positions, $50) or Ansmann’s 10-bay 9v charger at $70. Personally, I wouldn’t spend the extra money on the Ansmann rack mount chargers (they are over $500), unless you really need them racked.

You can find the Maha chargers, Powerex and iPower batteries at Thomas Distributing. Horizon Battery handles Ansmann batteries and chargers (and the folks there are super-helpful if you have questions).

Rechargeable Batteries—Why You’ve Been Burned

This has been one of the most fascinating topics I’ve ever written about. As I’ve been Twittering and reading conversation threads on the CTDRT boards, there seem to be three camps of people in the rechargeable battery debate. The first group has used them for years, loves them and wouldn’t consider going back to alkaline batteries. The second group has never used them, though most have heard the horror stories and are leery. The third group has tried them, and had bad experiences. The phrase, “I’ve been burned too many times, I’ll never trust them,” has been thrown around dozens of times just in the last few weeks. This post is for the second and third groups. If you’ve been burned, I’m going to explain why, and if you’ve heard the stories, I’ll show you how to avoid them.

By way of introduction, know that I have been using rechargeable batteries in wireless mics (and a lot of other stuff) for almost four years. I’ve tested them, and have gone through hundreds of services using rechargeable batteries without a problem. Yes, hundreds of services. Far too many people have one bad experience, don’t investigate the cause and swear them off. The fact is, I’ve had just as many ProCells die on me at the wrong time as I have rechargeable cells–and in each case, it was always been my fault—I simply forgot to change them.

There are four things you need to know in order to get the most out of rechargeable batteries. Failing to understand and implement these things will guarantee bad experiences. However, trying to stretch a ProCell for 2 weekends worth of services is a bad idea, too. Keep in mind that rechargeable batteries behave differently than alkalines. Expecting them to be the same will only frustrate you. However, follow these guidelines and you’ll have great success; and save a ton of money.

Use Good Batteries

This is one of the key factors in getting good results. A lot of people went down to K-Mart 10 years ago, picked up a $10 pack of four NiCd AAs and a charger, tried them in their mics and went down in flames. That explains 50% of the “bad experiences.” To use rechargeable batteries in wireless mics, you need to use a more modern chemistry, Nickel Metal Hydride, or NiMh. The batteries need to be rated for at least 2000 mAh (I like 2500 and higher). mAh stands for milliamp hours and is provides a guide as to how much energy the battery can store. If you pull open your junk drawer and find a bunch of 1300 mAh NiMh batteries that are 5+ years old, that may explain the other 50% of the “been burned” statements.

A ProCell is rated for somewhere around 1800 mAh. The modern, high quality batteries from Sanyo, Powerex and Ansmann (with ratings from 2700-2850 mAh) absolutely blow ProCells away; as I showed you the other day with the test results. Even a 4-year old Ansmann 2700 beat a ProCell by almost 4 hours. And these newer batteries are rated for between 500-1000 charge cycles. Figuring one or two cycles a weekend, that could easily mean 5 years or more on one set, provided they are taken care of.

If your experience with rechargeable batteries does not include these newer batteries, you simply don’t have enough experience to make an informed decision. Sorry, but it’s true. You really need to check out the winners of the battery shoot out before making a decision.

So good batteries are important, but there is another component.

Proper Charging

The second key component to proper use of NiMh batteries is the proper use of a  good charger. Using a cheap “rapid” charger will not fully charge the cells, will overheat them and shorten their life. Modern, smart chargers are readily available, easily affordable and will charge the batteries at the correct rate to fully charge them, while avoiding over-heating. They will then switch to a trickle charge mode to keep them at peak capacity.

So what is a “proper charge rate?” Most battery manufactuers recommend a charge rate that is between 0.5-1.0c. That is to say, the charge rate should be one half to full capacity of the battery. So, if a battery is rated at 2000 mAh, the recommended charge rate would be 1000 mAh, and max charge rate 2000 mAh. A full charge will take from 1-2 hours at those rates, respectively.

If you have the time and want to extend the life of the cell, charge at .25c. Sanyo recommends a charge rate between 300-500 mAh for their Eneloops (rated at 2000 mAh). Charging at those rates will give you somewhere between 500-1000 cycles, according to Sanyo. The other batteries I tested have similar ratings.

Personally, I like chargers from BTI, Maha or Ansmann; especially the ones that have selectable “soft” charge rates. I buy enough batteries that I can spend 4 hours charging them, so I charge at 500 mAh. Once the batteries are well charged, it’s important to know how to utilize them properly. And that brings us to…

Proper Cycling of Batteries

To ensure good results (“good” defined as the mic not dying mid-service), it’s important to use the batteries properly. Fully charged batteries should always go straight from the charger to the mic. Once the charger is empty, it should be re-filled with another set of batteries. When the service or event is ended, remove the batteries from the mics, and charge. If you have enough charging bays, you can simply alternate from one set to another. However you do it, you always want to go from charger to mic.

The reason is that NiMh batteries will self-discharge over a period of 30-60 days. So while you may not lose a lot of capacity from Sunday to Saturday, you’ll be down 10-20% or so. Why push it? Charger to mic, and charge immediately afterward. Keep a set on the charger all week and you’ll always have fully charged batteries to work with.

Some are concerned about the “memory effect,” the loss of capacity that happens when NiCd cells are recharged before being fully depleted. NiMh cells have no significant memory effect, so charge them when you’re done using them. Don’t stretch them farther than needed.

Good chargers include a refresh cycle that will fully discharge each cell, then fully charge it again. It’s a good practice to do this every 3-4 months. This procedure will prolong the battery’s life and ensure top performance.

Understanding Discharge Curves

Another main factor in the “I’ve been burned” phenomena is the different discharge curves between an alkaline and NiMh battery. An alkaline battery drops off in a pretty linear fashion. A NiMh, on the other hand, quickly drops from full voltage to something less than that and holds there for a long time. When it drops off, it drops of the cliff very quickly.

Discharge curve of the Eneloop (blue), a Sanyo NiMh (black) and an Alkaline (pink). I grabbed this from Sanyo’s Eneloop website. Most battery meters in wireless mics are calibrated to the discharge curve of an alkaline battery. As the voltage drops off, the meter can predict approximately how long the battery is likley to last. However, with a NiMh, the voltage holds, then falls off very quickly. This is why it’s not uncommon to see a NiMh battery go from 4 bars to 0 in 5 minutes. The meter has no idea how to know where the battery is.

Some newer mics have battery meters that can be switched between alkaline and NiMh (the Shure UHF-R does for sure), and those can be a help. But there’s still no substitute for doing some testing and finding out how long they last in your mics. Once determined, you know how often you need to change them, regardless of meter rea
ding.

For example, I know that the Powerex and Sanyo 2700 mAh batteries will run a good 12-14 hours in our mics. So, I can feel confident putting them in Saturday afternoon for rehearsal and letting them run through end of service (about 4.5 hours total). I can then put in a fresh set Sunday morning and be fine through the end (about 5 hours total). I don’t expect to ever have one go down, unless it’s a fluke. But again, that happens with ProCells, too.

Those are some basic principles for the proper care and feeding of NiMh batteries. As I said, if you haven’t tried them lately, you’re throwing money away.

Battery Shootout—Mike’s Picks

If you’ve missed the previous two posts on rechargeable batteries, you need to go back and read about the test, and the result. Got that? OK, good. So now we’ve run the test, analyzed the results, it’s time to pick a winner, right? Sure, fine. But let me remind you what didn’t win: The ProCell. It was beat by every rechargeable I tested, including a 4-year old abused battery from home. With that in mind, there are really no losers. However, there are a few standouts. And since we just wrapped up the 2010 Winter Olympics, we’ll hand out some medals. First, the Bronze.

The Bronze Goes To: Ansmann 2850

As I said earlier, I was a bit surprised that this cell didn’t outperform the two lower-rated cells that beat it. After all, it has a 150 mAh higher rating. But in my research, I’ve learned that the mAh rating is only a guide for power storage, what we need to know is power delivery. And while the Ansmann 2850 held up well at 13.25 hours, it wasn’t enough to beat the top two. Still, it beat the ProCell by 3.5 hours, which is no small achievement. And one thing I can say with confidence about Ansmann batteries is that they last for a long time; consider the 4-year old abused 2700 batteries I tested, they ran for 13 hours as well. You’d go through a lot of ProCells in 4 years, so this is not a bad choice at all. I now have 8 of these in my inventory, and I’ll be curious to see how they hold up over the years.

The Silver Goes To: Powerex 2700

This is a tough call. The Powerex and the Sanyo 2700 both ran to 14 hours. They also have the added benefit of being the same diameter as a regular AA, so they slide in and out of the mics easier (the Ansmann is a tiny bit bigger and sticks in the UR2). Frankly, I would have no problem recommending them at this point. So why the silver? One reason: The Powerex held at 4 bars for 1 hour less than the Sanyo. Now, this may not be completely indicative of the actual voltage drop, and it may well change over the course of 6 months or a year. However, for now, the Sanyo gets the top spot.

The Gold Goes To: Sanyo 2700

In this round of testing, the Sanyo was the standout. It held at 4 bars for nearly 11 hours; over an hour after the ProCell was dead! And it still gave 3 hours of warning before it needed to be changed. I could actually run an entire weekend with one set of these (I wouldn’t, but I could). In fairness, the other two top contenders could do the same; I’d just feel better about doing it with these. They are also the same size as a regular AA, which makes it easier to get into handheld mics. The real test will come in a couple of years when we see if they still hold up as well or better than the Ansmann or Powerex.

Honestly, I don’t think you would go wrong with any of these batteries. The Powerex and Sanyo are $3.12 and $3.19 each, respectively; the Ansmann are $3.62. Over the course of 3-4 years, that cost is academic. Find one you like and stick with it.

UPDATE: 3/18/11

Reading back through this post has been interesting. After a year of use, either the Sanyos and PowerExs have grown in size (which is possible), or I was mistaken when I wrote this. Right now, my guys reach for the Ansmanns first because they slide in and out of the UR2 handhelds much easier. The Sanyos are very hard to get out (so much so that we rarely use them anymore), the PowerEx cells are in between the two. I have no explanation for this, other than it is possible the cells have expanded slightly due to the charge/discharge cycle. I recently re-tested these batteries, and found the Ansmann have held up quite a bit better over the previous year.

END UPDATE.

The rest of the field was composed of newer technology, low self-discharge formulas, namely the Ansmann MaxE and the Sanyo Eneloop. Both performed admirably, however, the top three clearly outclassed them. And really, that’s no surprise. On the other hand, either of these batteries would be great for applications where you need batteries in place for the long-term—they’re rated to hold 80% of full charge for up to a year. I’ve used Eneloops in my DSLR and found nothing compares to them. My Pentax is one of the most power-hungry DSLRs out there (meaning it draws the highest current) and the Eneloops radically outperform anything else I’ve tried; it’s all about matching the right cell to the application.

Next time I’ll go over some reasons why people have had bad experiences with rechargeable cells and how to achieve good results. Stay tuned.

Thanks to our sponsors

I would be remiss if I didn’t mention two companies that made this test possible; Horizon Battery and Thomas Distributing. Both sent a variety of batteries and chargers in for the test. I’ve purchased from both companies in the past and heartily recommend them. David Schliep from Horizon was especially helpful. Also, in the interest of full disclosure and in accordance with new Federal guidelines, I’m required to tell you that Thomas Distributing gave me some batteries and two chargers for this test. That in no way affected the results, or my opinion of the batteries or chargers. I call them like I see them, and I have in the past purchased the same or similar equipment from Thomas.

Battery Shootout—The Results Show

Last time, I explained the test parameters, the setup and listed the batteries under test. Go back and read that post if you want to see the test conditions (yes, I had the battery meters set correctly to match the chemistry of the batteries). Today it’s time for the results show. Based on the traffic on Twitter last week, this could be more eagerly anticipated than the American Idol results show. And we’ll get to the results right after the break. I’m kidding. Sit down, Ryan.

So let’s get right to it, since you’ve probably already looked at the graph (can someone figure out a way to reveal a graphic only after the reader has reached a certain point in the post?). The bottom line, the ProCells lost. Big time. In fact, the worst rechargeable battery beat the mighty ProCell by an hour and fifteen minutes. The best rechargeables outlasted the ProCell by three and a quarter hours. Surprised? Actually I am too.

Quite frankly, I’m most surprised at how long all of the batteries ran. I set the test up so I could have audio driving the mics for about seven hours. I figured most of the batteries would be dead by then. Surprise! All but one of the NiMh batteries were still at 4 bars at 7 hours (the MaxE was at 3) and the ProCell was at 1. Since I had to set the stage for our mid-week bible study, I set the mics in our audio storage room and let the test go until the batteries all died. Much to my surprise that last two shut down at a staggering 14 hours! Let’s look at the graphs… By the way, the red line is the point where the mic switched off. Once a data point drops below the line, the mic is no longer transmitting.

I took data points at 15 minute intervals; I figured that would be enough resolution for live work. If you try to cut battery life closer than that, you’re braver than I (or just crazy, not sure…). Based on this graph, a few things are pretty clear. First, any of the batteries are more than capable of safely keeping a mic running for 2-3 church services. Second, there are three tiers of batteries here. The top contenders are the Ansmann 2850, the Sanyo 2700 and the Powerex 2700. The middle ground is occupied by the low self-discharge Eneloop and Max-E; no surprise, they’re rated at 2000 mAh and 2500 mAh respectively. The bottom rung in performance is clearly the ProCell.

Another thing that becomes clear is how different the discharge curves are between chemistries. The Alkaline drops off in a very linear fashion; it looks pretty much like a staircase. The top NiMh batteries drop slightly off full voltage quickly but then stay there for a long, long time before plummeting off the cliff. The low self-discharge batteries are sort of a middle ground. I have a lot more to say about these characteristics, but I’ll wait until Friday.

Since it’s a bit difficult to see how each battery actually performed, let’s take a look at each graph individually, starting with the top batteries, in alphabetical order.

As predicted by Robb MacTavish on Twitter, the PowerEx was a top contender. Though only rated at 2700, it bested the Ansmann 2850 (though 45 minutes is pretty academic). One of the things I like about the PowerEx is that it held at 4 bars for a solid 10 hours! It also took 4 more hours to drop to 0, meaning you have a lot of warning to change out. I would have no qualms about using these in a service, or for three in a row.

The Sanyo actually performed a little better than the PowerEx but since S comes after P, it’s listed second. Like the PowerEx, it held at 4 bars for nearly 11 hours. In fact, the ProCell was dead before the Sanyo dropped below 4 bars. How about that? Again, there was ample warning on the meter before it died. But it’s probably good practice to change them out at 3-4 bars anyway.

I was kind of surprised that the Ansmann didn’t outperform the lower capacity Sanyo and PowerEx. David Shliep of Horizon Batteries advised me that the batteries should be conditioned a few times for maximum capacity. I ran them through 3 cycles on the charger; perhaps they need a few more. Still they held at 4 bars for 8 hours which would be amazing if the Sanyo and PowerEx contenders weren’t in the ring. And 13.25 hours overall is pretty respectable.

Though low self-discharge batteries aren’t really needed for wireless mic use (you should always pull from the charger and back fill the charger), I was curious about how they would hold up. The Max-E dropped off a little more like an alkaline battery, with each stop on the meter getting a little shorter. Holding at 4 bars for 5 hours, and taking another 6 hours to go totally dead, these wouldn’t be a bad choice. But I think there are better (and more cost-effective) solutions here.

I’ll admit it, the Eneloops were my favorite going in; they outperform anything I’ve tried in my DSLR. Their specialty is delivering high current and discharging predictably even under high loads. Though they dropped dead 30 minutes before the Max-E, I would rather have Eneloops in my mics. Why? Because they held at 4 bars for 2 hours longer than the Max-E. You get fair warning when they’re going to go (change them at 3 bars). They held up well considering their capacity is 700 mAh less than the top performers. However, for wireless mics, I’ll stick with the regular Sanyos.

Pulling up the rear is the old standard, the ProCell. If it weren’t for every other battery in this test, nearly 10 hours of life would be pretty impressive. In fact, it’s about what the UR2 is rated for. But since the top batteries beat it by 4 hours, it’s less impressive. The thing the ProCell has going for it is it’s very even and predictable discharge curve. And at about 40 cents, it’s about 12% the cost of the Sanyo 2700. On the other hand, I’m pretty sure I can get 8 charge cycles out of the Sanyo, after which I’m making money. Also, keep in mind that Cirque du Soleil uses rechargeable batteries (Ansmann 2850s to be exact) because they last longer than alkaline batteries. Guess that makes their audio guys as brave as the performers.

During the testing, I was Twittering throughout the day. While some were interested to see the data, many were not convinced. Some suggested the batteries wouldn’t hold up for more than
a few months. So I’m doing two things: First, I’ll be using these batteries in our services and keeping track of them. I’m marking them and will repeat this test with the exact same batteries every six months for the next several years. Second, to shortcut those results, I grabbed a few Ansmann 2700’s that I bought in 2006 for my DSLR.

These batteries have not been treated kindly. I have no idea how many cycles they have on them, but I have used them heavily, then left them in a drawer until they were almost completely dead, charged them at rates higher than recommended, then left them for dead again. To see how old, mistreated batteries would hold up, I threw them in the charger overnight then repeated the test under nearly identical conditions.  Here’s what happened.

I had no idea what to expect, but the results surprised me anyway. The voltage drop happened quickly, but then it stayed at 2 bars forever. In fact, I got tired and went home, cutting the test off at 13 hours. The mic was still running at 1 bar. My guess is it would have been dead in another 30 minutes or less so I didn’t mind shutting down the test. Like the previous day, I had 7 hours of music time to drive the audio components. Then we had a school district choir on stage for the final 6 hours, so there was some audio hitting the mic. And it still beat a brand new ProCell. This battery might make me nervous in a wireless mic because it would seem 2 bars wouldn’t last long. But that would be an incorrect assumption. It ran for 10 hours at two bars. And I was really nervous, after 4 years of use, I wouldn’t mind replacing it.

This post is insanely long, so I’ll save my conclusions for another post. Don’t worry, I have a lot more to say on this matter…

Thanks to our sponsors

I would be remiss if I didn’t mention two companies that made this test possible; Horizon Battery and Thomas Distributing. Both sent a variety of batteries and chargers in for the test. I’ve purchased from both companies in the past and heartily recommend them. David Schliep from Horizon was especially helpful. Also, in the interest of full disclosure and in accordance with new Federal guidelines, I’m required to tell you that Thomas Distributing gave me some batteries and two chargers for this test. That in no way affected the results, or my opinion of the batteries or chargers. I call them like I see them, and I have in the past purchased the same or similar equipment from Thomas.

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