I bought a light that takes AAAA cells. Bad idea as rechargeables are impossible to find in this size.
I did find these: http://www.radioshack.com/product/index.jsp?productId=4053228&CAWELAID=488951926
But, I only have a LaCrosse BC500 (500mAh fixed current) charger. How bad is it to charge a NiMH cell at 1.6C?
dunno, but you could charge 2 in parallel...
what light did you buy that uses AAAA batteries?
I bought some rechargeable AAAA to use with my klarus mi x5, unfortunately these cells were a little wide and did not fit in the battery tube. I'm happy to resell them to you at minimal cost, if your interested
I don't think a smart charger would like doing two batteries in parallel.
The light is a Maxxeon WorkStar 220 with a Cree XP-E LED. It's a really nice light. Good quality and the tint of the LED is typical of the XP-E, not too blue (unlike the XP-G which is REALLY blue or the XP-C which is really green). I was also talked in to it by my flashlight dealer. He was supposed to have a Streamlight ProTac 2AAA for me but got this instead. I hate that I can't use rechargeables and he wants me to buy packs of AAAA batteries from him. I might just sell it.
how would the 'smart' charger know?
I use my lacrosse to charge every size of 1.2V nimh and nicad I have. I bought AAA to AA adapters and wired them to C, sub C, and D battery holders. the adapter goes in the charger...the battery in the holder.
I could very well be wrong, but I'd think it would 'see' two AAAA in parallel connected to a dummy battery as a AAA...
the downside is the temperature sensors are useless because the cells aren't in the charger.
Listen to him, hes right.
Only downside would be sensors . The batteries will still get charged.
The charger would know because it expects to see polarity reversal of one cell after a full charge. If there are two cells, it will miss the termination as one cell will mask the reversal of the other cell when a full charge is achieved.
Everyone please take this concept as just an idea and don't if any NiMH 9v are constructed the same way. I recently took a an alkaline 9v a part and it had 6 AAAA sized cells in inside. My smart charger does't smart charge 9v it timer charges them at very low rate. I have bought AAAA for my Streamlight Stylus Reach and they are stupidly expensive.
polarity reversal?!
that is news to me.
I thought the lacrosse terminated based on this http://www.acmegadgetlab.com/whatisdeltavchargecontrol%3F
there's some discussion of delta v termination w/ parallel cells here http://www.powerstream.com/NiCd.htm
I guess the question is, would it be worse for the cells than the higher charging rate?
I've got 3 nimh in parallel charging in my lacrosse bc700 right now, we'll see how they end up...
Sorry, I was typing while working. I meant delta voltage. I was thinking that the voltage drop was from polarity reversal, I don't know why. My mind was elsewhere.
Even so, if there are multiple cells in parallel on a charger (a smart charger, that is), the charger will probably miss the termination as both cells won't drop voltage at the same time and one is going to mask the drop of the other.
my 3xAA finished during the day and were on trickle for a few hours. measured immediately after removal and read 1.46, 1.47, 1.48V. I would guess that the resistance of the different slots in my holder varies as much as the battery resistance.
anyway, I agree it isn't ideal, but it'd save you from buying a hobby charger...
This is what i did today because of willie's post :glasses:
Where are the AAAA cells please??
duh :sick:
I feel deceived.
willie.. :evil:
here 
:
funny, isn't it? Different 9V's are build up in a completely different way. Noticed that a few years ago. Depends on brand, and one way or the other is not neccessary the better battery 
.
That aint gonna happen that often, eh, Kreisler ;)?
I have disassembled my varta 9V ni-mh battery.
7 very small batteries inside.
May be we can make a ni-mh 10440 battery using 3 of them and some spacers.
I have also an older varta battery, which is the same as this vikipedia picture.
I don’t think it would kill them. NiMH are pretty forgiving. I know some cheap rapid chargers put more than 1C into NiMH cells. I would try it, but that’s just me. As others said, 9V can be a source of AAAA cells.
You could go with Alkalines. I've seen several AAAA Alkalines and the price is cheaper for them. As low as $4 for six of them. Search AAAA Alkaline.
Just take apart some dead 9 volts, most of the time one cell will be dead and the rest will be fine. I know Duracell and Safeway brand ones have AAAAs in them.
I did a similar thing a while back but mine had ones that were 13mm diameter (bigger than AAA) so I made a nimh 14500 with around 150 mah capacity.
Kreisler, “Extra Heavy duty” are carbon-zinc, not alkaline.