NiMH battery experts: Need your help

[Gombessa]

This isn't specifically about lights, but I figured it's the best place to ask. If it helps, assume I'm asking for backup light purposes

I'm in the market for a few (like 4-8, no more) rechargeable AA batteries along with a standard AC charger, and I want the most bang possible, buck be damned (within reason). From my quick'n'dirty research, it looks like 2,700mAH NiMH cells, such as these from Sanyo, are pretty standard. It also looks like there are some 3,000mAH cells out there, which frankly I'm a bit dubious about (just like the 7hr battery life claims for my laptop).

So, what's the scoop on AA batteries, and which do you use/recommend?

 

[Puffer Fish]

Hummm... fairly complex issue actually.

First off, Nimh's seem to have some very questionable capacity ratings... as the capacity varies with how fast one discharges them, and there seems to be no standard rating rules.

Second, from experience, the higher the capacity, the more likely they can be damaged.

Third, they don't work well in LED lights (lower voltage, and fairly fast self discharge.)

So, here is my experience with batteries:

1. For LED lights, I recently got some of the new Zinc based rechargable batteries....and they require a special charger... and are only right now available in AA, with AAA to come soon...love them... they are brighter, hold a charge really long (going on one month with one set)...not tried them in other equipment....but they are 1.6 volt batteries.

2. For my strobes... I now only use the slow discharge, japanese cell guys... Duracell or Sanyo...lower rated capacity, but they seem to actually last longer and they don't seem to damage as easily... have yet to have a set go bad.

3. For maximum capacity, I have had great luck with Power2000 2,900's... which actually surprises me. but they have been good now for over 100 cycles.

For a charger... can only recommend that you get the Lacrosse (smallest of the high tech ones). It will show you how much power it takes to charge each battery, so if one does go bad, you will see it and can replace.

 

[Hatul]

I now get the low self discharge batteries like the Sanyo Eneloop, the Rayovac Hybrid, precharged Duracell and other brands. That's what I would recommend. The good thing about them is you can leave them in your light or strobe and don't have to worry about charging prior to use. They're also good for low current devices that sit idle for long periods. And I would stick to brand names, skip the generic Chinese ones.

Adam

 

[Gombessa]

Thanks for the responses. I'm looking for a tad more juice than the current 2100mah I have, so I'll go with the Sanyo 2700mah + the LaCrosse charger. I definitely like the idea of seeing the actual charge of each battery (and not having to charge in series).

 

[CompuDude]

Just head over Thomas Distributing. Maha makes fantastic high capacity (not always the absolute highest capacity, but the most reliable) NiMH batteries.

For frequent-use lights, the relatively high self-discharge rate of NiMH rechargeables isn't an issue. Just be prepare to top them off on a semi-regular basis. Not every dive, but perhaps every few dives. (unless you're significantly running them down with each use, obviously)

For backup lights, I tend to split between alkalines and the low self-discharge (LSD) rechargables. I use 3x C alkalines in my Photon Torpedo (my serious "oh sh**!" light) and Sanyo Eneloop LSD rechargeables in my little Dorcy and Intova Compact backups, which are what I reach for first on rec dives where I need a light for a moment, or to pass off and loan out. It's nice to be able to top them off every now and then and know I have a nice full charge, and keep the Alkalines untouched for serious doo-doo.

Maha makes some of the best chargers made. Full diagnostic displays, individual charge level monitoring for each slot, etc. You can get them at TD as well.

I'd look at the Maha Powerex 2700 mah AA's for the frequent use items (I use these in cameras and strobes and focus lights, since they're likely to be used heavily and can easily be topped off the night before the dive), and either the Eneloops or perhaps the Maha Imedion LSD batteries for anything where you want a longer shelf life in your rechargeable. Skip the Accupower batteries... They come in higher capacities (especially C-cells) which was great for my Light Cannon, but I had a lot more of the cells die early compared to the slightly lower capacity Maha cells.

 

[CompuDude]

I now get the low self discharge batteries like the Sanyo Eneloop, the Rayovac Hybrid, precharged Duracell and other brands. That's what I would recommend. The good thing about them is you can leave them in your light or strobe and don't have to worry about charging prior to use. They're also good for low current devices that sit idle for long periods. And I would stick to brand names, skip the generic Chinese ones.

Adam

Eneloops are fantastic. I'd be wary of the others. Interestingly, the Duracell precharged batteries have two varieties: Ones made in Japan are actually re-badged Eneloop batteries made by Sanyo, and are as good as you'd think. The ones made in China, however, are a lot more hit and miss. It's hard to find a company online that will let you specify, though, so this is a better choice for in-person purchases where you can look over the package carefully.

For low self discharge, I would not have much, if any, hesitation to try the Maha Imedion's as well. I haven't yet, but that's only because I have all the Eneloops I currently can make use of.

 

[Bubbletrubble]

+1 on the Maha battery chargers. The model I have (MH-C808M) charges AAA, AA, C, D batteries. Very happy with mine. Pricey but works great.

I use NiMH rechargeable batteries (Powerex, 5000mAh "C" type) in my Princeton Tec Shockwave LED light. I typically do 7-8 hour-long night dives before having to recharge them.

I use AA Sanyo Eneloops in my UW camera. They work great. I haven't tried them in my backup lights yet.

 

[CompuDude]

+1 on the Maha battery chargers. The model I have (MH-C808M) charges AAA, AA, C, D batteries. Very happy with mine. Pricey but works great.

I use NiMH rechargeable batteries (Powerex, 5000mAh "C" type) in my Princeton Tec Shockwave LED light. I typically do 7-8 hour-long night dives before having to recharge them.

I use AA Sanyo Eneloops in my UW camera. They work great. I haven't tried them in my backup lights yet.

Same here. (same charger, too!)

The Maha charger juices up the Eneloops very well, also. And MUCH faster than the stock Sanyo charger does.

 

[Bubbletrubble]

Same here. (same charger, too!)

The Maha charger juices up the Eneloops very well, also. And MUCH faster than the stock Sanyo charger does.

Great minds think alike.

I could go on and on about where/how I use those NiMH rechargeable batteries (Apple bluetooth keyboard, otoscope/ophthalmoscope, remote controls, etc.). It's worth the extra cost knowing that I'm not making used battery donations to the landfill.

 

[spoolin01]

Unless you need (or want) the marginal performance improvements that are may be offered by a more expensive battery, I'd just go with whatever high cap garden variety NiMH you can find for a good price. I've used many AA batteries of most of the 'name' brands (I doubt they own the factories, so what's in a name?) and also the Tenergy brand, which I take to be a generic. I don't see a difference in use - though I don't run mine to exhaustion - and I certainly don't see that the noticeably high failure rate is any worse with the Tenergies, not at all. Some have said that dropping the batteries breaks them, so I'm going to be more careful. The AAs I use in strobes, like the Ikelite DS-51 size, and charge every other dive (maybe 200 varying power flashes per cycle), so if there's truly a useful capacity advantage in one brand over another, it's not an issue in my use. Some cameras are reported to be battery sensitive and to work better with the low self-discharge technology batteries (like Eneloop), but that won't affect dive light performance, unless the useful capacity is truly higher. I wouldn't pay more for name or technology unless I found the standard issue to be lacking for my uses, or the price difference small. I haven't checked prices in awhile, now that I've got enough batteries. I use the 5000 C and 10000 D Tenergies in dive lights, also Maha, GP, and Accupower Cs, where I do run them until they die or I run out of tanks, and I don't see any difference in quality or performance there either. Again, I'm not evaluating them at the margin, just as used, so if I can get a couple hours of full brightness, and then recharge, I'm happy. By the way, it seems to me like the initial brightness advantage of alkalines is lost fairly quickly, and the NiMhs go 50-100% longer so I like them better for that. Those 1.6V zinc batteries should be great for most lights (assuming they hold voltage during discharge under load), compared to alkalines or NiMH - but some LED lights use drivers that may limit that advantage. Maybe someone with more knowledge of that will comment.
I like the LaCrosse charger for it's programmability and the display info, also the Maha C401 since it has a 100mA charge setting. The charge rate thing is contentious I gather, but it seems good to me to charge at a low rate to keep the batteries cool and for uniformity.

Sorry for the long post, I see now you were asking about the best battery technology...