NiMH is a lot better than alkaleaks, especially for power output. They’re not as good as lithium-ion, but a 1000+ lumen 4xAA light will easily run on NiMH.
Most good 4xAA lights have low-voltage cut-off, so shouldn’t reverse-charge your cells even if you have a weak one. Besides, I’ve reverse-charged Eneloops, and they’re still perfectly fine with no loss of capacity. Probably lost a few cycles, though, so it’s definitely not good for them.
One thing that 4xAA lights have going for them, is that you can find batteries absolutely everywhere. The alkaleaks certainly aren’t good, but it’s better than nothing if you have no other choice.
Yes you would be dead in a car here in summer under sun with windows rolled up. But I leave my lights in car in summer. my niece killed her dog leaving it in car a couple hours.
They’re starting off in the hole at 4.8V, and by the time one is spent, that’s a sudden drop to 3.6V. Hopefully that’s be low enough under load that a light that thinks its got alkaleaks would start warning you (as in blinking the light itself or cutting off, not just turning the indicator from yellow to red or something), but you’d have to know the spex of the light itself.
Marginally, but yeah. Still burning off the Rat Shacks and Rayovacs I unearthed…
I have a temperature console that takes 4 AA’s. I was using four Eneloops in them, and one must have been a bit weak or maybe I didn’t fully charge it. When I noticed the console wasn’t working (it was probably dead for a few days), I took out the cells and measured their voltage with my DMM.
Most of the cells were down around 0.8v. However, one of the cells measured about –0.7v. It had been reverse charged.
I couldn’t recharge it in any smart charger, since the charger would reject it as being put in the wrong way. So I used a dumb charger, which just forces current into a cell no matter which way around you place it. After a few minutes of that, its polarity was restored, and I then could charge it using a regular charger. It charged up fine, and discharge capacity testing indicates it didn’t lose any capacity.
It probably lost some cycles, though. Reverse charging isn’t good.
They could’ve all been reasonably well-matched, in that the other 3 were certainly dead, but not reverse-charged/-ing.
Worst case is if the other 3 were still happily pushing out 1.2V at however many amps, and force-feeding the runt of the litter the wrong-way. That’s when you fry ’em but good.
Did that with NiCd cells one time, and one vented. Slow hiss, nothing dramatic, but it still stunk.
Yeah, they weren’t badly un-matched. One was just a little weaker (less capacity) than the other 3. They were all in series. So, the 3 “good” ones were still happily pushing out 0.8v x 3 = 2.4v. The 1 weak cell was reversed at 0.7v. So, the battery was still providing 2.4v 0.7v = 1.7v in total. So, it was still reverse-charging the weak cell when I discovered it.
Below 0.9v there’s almost no capacity left in Eneloops. So, it doesn’t take much of a mis-match for a reverse-charge scenario to happen when you drain a multi-cell battery. It probably wouldn’t have happened in a 2-cell series battery. Much easier in a 4-cell series battery.
And thats exactly my draw to a multiple AA format. Specifically my 5.11 A6 in my truck. So far its been the perfect truck light (although I would like a better color tint and higher CRI than the old XML produces). Similar, though less reliable, is the Coast HP14 in my wife’s truck.
