Highest capacity AAA NiMH batteries currently available?

I have a Coast PX25 that I use for a 6 mile night walk that I take with a walking group. The light is GREAT for this in terms of brightness (not too much, not too little) and size. However, it uses AAA batteries, and it sucks them down like a vacuum cleaner. Somewhat more than half way through the walk (maybe 2/3), my Duraloops are pretty much DONE. And changing batteries on the move (ESPECIALLY in a light with a battery holder) is not the easiest thing to do (it's a pain to have to stop, and then catch up again). So what I would REALLY like is the AAA NiMH battery with the highest capacity possible. It doesn't have to be LSD, as the batteries will be charged immediately before the walk and used pretty much ASAP. But I'm looking for something that can REALLY put out in terms of mAH. Any suggestions?

If your Eneloops (800mAH) only last 2/3 of the required time, you need about 1200mAh to last the whole walk. I've seen Chinese-made no name brand NiMH AAA claim as high as 1250mAH but AFAIK the highest rating from a credible brand is about 1000mAh.

I think what you need is a regulated flashlight. A regulated 2AA flashlight could easily give you 100+ lumens for over 2 hours. Average walking speed is 3 mph so I'm guessing your walk takes about 2 hours.

I think 1000mAh is about the highest. These have been tested by many people to hold 950mAh:


See Rule #3 Do not Hot Link images. Please host on an image site, Imageshack or similar and repost – Thanks Norm

http://www.hobbyking.com/hobbyking/..._900mah_Low_Self_Discharge_ready_to_use_.html

I tested a few of the 900 mAh Turnigy cells and got an average of 986 mAh, which is more than the 800 mAh of Eneloops, but still probably won't get you all the way through your walk. You could bring a second flashlight (always need a backup anyway). There are multi-mode lights that will let you have the light on in Medium for better runtime and still get pretty good output, and then when you need full brightness you can bump up to High.

The specs of this light say 6 hour 15 min runtime. I suppose this is with a lower output? Anyway, looking into the highest mAh AAA batteries, you'll possibly find yourself in the position to change them quite often, every few months. They just don't last and the capacity diminish and within one year they'll be like a normal AAA eneloop if not worse in terms of capacity and probably will perform even worse, so you'll be at the same case again (not sure about higher capacity LSD however, I'm certain for the non-LSD they'll suffer). The maximum real is close to 1000mAh, anything above that is almost certainly exaggeration. If your light does have a lower setting, why not use it assuming the lowest can deliver those [SIZE=-1]6 hour 15 min runtime[/SIZE]? The other option is to carry another light or get one that delivers more runtime if swapping batteries is really that bad.

I've got some AccuPower 1200 AAAs that get pretty close to that 1200mAh mark--mid 1100s. They're HSD cells, but they do offer some more capacity than some of the others out there.

Chris

apagogeas said:

The specs of this light say 6 hour 15 min runtime. I suppose this is with a lower output? ... If your light does have a lower setting, why not use it assuming the lowest can deliver those [SIZE=-1]6 hour 15 min runtime[/SIZE]?

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The Coast PX25 is single output 208 lumens for 6 hours 15 minutes. It can claim that ANSI FL1 runtime by starting at 208 lumens and running down to 21 lumens (10%). This is typical of the unregulated Coast / LED Lenser lights.

Yamabushi said:

The Coast PX25 is single output 208 lumens for 6 hours 15 minutes. It can claim that ANSI FL1 runtime by starting at 208 lumens and running down to 21 lumens (10%). This is typical of the unregulated Coast / LED Lenser lights.

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This is true. There ISN'T a lower output, and this is an unregulated light. Furthermore, I'm sure they're also using alkaline batteries to get this runtime. Unlike NiMH, alkaline batteries really don't run long at full brightness. But they will go forever in a light like this in a very dim state. So I'm sure you COULD get six hours from the thing with alkalines, at least if you are willing to put up with very little light output. But at that point, there are other lights with lower output that would run longer with NiMH.

Anyone know anything about Ansmann batteries. They make an 1100mAH AAA, and I've heard that it's pretty much for real as far as capacity. Not sure whether it would be enough. But it might be worth looking into.

Sanyo 1000mAh made in Japan cells are highest capacity AAA's available, IIRC. They test out at real 1000-1100mAh.

Seems to me you simply need to get a different flashlight - an AA one that will easily manage the two hour walk.

Dubois said:

Seems to me you simply need to get a different flashlight - an AA one that will easily manage the two hour walk.

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I actually DO have other flashlights that can manage a two hour walk (which use AA, C, and D batteries). But I just like the PX25 for this walk. And if I can possibly find a way to make it run longer, that would certainly be nice.

I think you might be out of luck. Actual capacity of 1200mAh+ seems like a stretch for AAA NiMH cells.

Is the Coast PX25 able to take a rechargeable Lithium-ion cell in place of the battery holder? Since there's no low voltage protection you'd have to watch out for overdischarge...

If I'm off the mark please ignore my suggestion. But I gather that this light runs on 3xaaa cells. Which I'm assuming are in a standard series tubular holder that many lights utilize.

My two suggestions:
1. Carry one extra holder pre filled with fresh cells for a quick change.
2. Rigg a holder to accept 3x10440's in parallel rather than series (at a minimum of 500mA each you get 4.2V @ a minimum of 1500mA). Get higher capacity cells and you have some left over for that "rainy day".

Edit: see if you can get either an 18350 or an 18500 in there with highest capacity available.

Sounds like your best bet, if you don't want to change batteries during the hike would be to use alkaline or lithium batteries instead of rechargeable batteries. By the way, since we're almost into winter, it's worth noting that Eneloops are about the only rechargeable option that works well in the cold. Higher capacity NiMH batteries start losing capacity in the 50's F.

At these discharge rates the Eneloops likely have higher usable capacity than alkalies.

Wrend said:

At these discharge rates the Eneloops likely have higher usable capacity than alkalies.

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Very true. I actually measured the tailcap current on this light, and it was .6A! That's pushing an alkaline AAA WELL beyond what it is capable of doing. As for low temperatures, this really isn't too much of a concern. This light actually gets quite warm during operation. And, of course, it will be clenched in my hand. I don't think it will get cold.

The flashaholic solution: Get a second light. When the first one dies, you take the other one out of your pocket.

I vote similar to shadowjk. with these modifcations and reasons.
Use two flashlights.
At a convient spot after the half way point, change flashlights.
So both will be approximately 75% discharged.
Recharge both to 95% full, not 100%
With this mild charging / discharging you should have MANY MORE cycles in the life of the eneloops / duraloops.
If these flashlights are not single cell lights but triple cell then this is especially useful advice to avoid reverse chanrging one of the cells.
By stoping with 25% left, reverse charging while using the light will rarely have the oppertunity to occur.

shadowjk said:

The flashaholic solution: Get a second light. When the first one dies, you take the other one out of your pocket.

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That's a reasonable idea -
but how about a slight compromise -
get another/spare battery holder -
that way the battery change can be pretty quick.

As for the original query -
Imedion AAA (LSD) rated 950mAh
Sanyo XX (eneloop) (LSD) rated 950mAh
Turnigy AAA (LSD) 900mAh (seems to consistently measure higher -
but beware there is an 800mAh version)