AA eneloops

[Flashanator]

Hi,

After a far amount of use on these. Off the chager they still seem less then alkaline aa's.

Is this right?

I usually charge them overnight but I tried my rapid MH-C808M NiMH charger which does all 8 eneloops very quickly.

Will quick charging them on my MH-C808M cause damage on?

thanks.

EDIT: forgot! I usually charge them up when there probably under half charged. Maybe I should wait till their almost drained?

 

[JBorneu]

What do you mean "they still seem less"? Less voltage on a multimeter? That's normal. They hold their voltage much better under load so they perform bettert han alkalines. Less initial brightness from an incandescent light? Normal, depending on configuration, because the voltage is less, but they will stay higher for most of the discharge curve. Less capacity (runtime)? Not normal.

NiMH cells have to be completely discharged every 20-25 cycles to keep them fit. If the capacity is less than it should be, try a couple discharge-charge cycles.

The charge rate of your charger is pretty high. This is not a problem in itself, but it can cause the cells to heat up too much which can harm them (resulting in less capacity). If the cells get hot during charging, get a charger with a slower charge rate or try blowing a fan over them while charging to cool them down. The description says it keeps the cells cool, not sure wether that is true, but I would hope it's true for such an expensive charger.

 

[Flashanator]

Ok thanks for the bit of info. When Using the MH-C808M charger they do get a bit warm. Ill stick with the ordinary eneloop charger.

Although charging my D-size NiMHs with the MH-C808M doest get them warm.

 

[VidPro]

Will quick charging them on my MH-C808M cause damage on?

not likly, that charger doesnt ever "overcharge" but i more often use it on the "soft" mode when i have time, that is a sweet 50-50 pulse.

when figuring on completly draining the cells, remember that in SERIES use, depending on the device, a "full" discharge of the batts, could cause some "reverse charge" when one of the cells is completly depleated.
so
when it comes to (purposfully) cycling the cells , use the machine, it will do it singularly, not in series, and it wont cause the dreaded reverse charge.

2000 ni-mhy do have slightly less overall power than a alkaline, WHEN the load is very small and it is allowed to rest between uses, but generally for most devices, even a 2000ma rechargable will walk all over a alkaline, AND then do that 500 more times too

 

[JBorneu]

Slightly warm during charging is not a problem, hot is a problem. Slightly warm is perfectly fine. The charge rate is high, but not too high if they're good cells.

 

[TorchBoy]

At higher currents they're only less (lower voltage) for a very few minutes. http://www.candlepowerforums.com/vb/showthread.php?t=173482

Warm isn't bad for Eneloops, but hot is. How warm are they getting? You can expect them to get warm at the end of their charge but that charger is good enough that it should terminate (pun on avatar) before they get hot.

 

[Linger]

cycle eneloops QUOTE]
?
1)I thought the eneloop was maintenance free.

2)What is deep discharge for an eneloop. I realise i've become aclimated to li-ion's and re-charge on partial discharge and iirc the eneloops don't get below 1.0v

2B)How low can they be discharged
2C)how low 'should' they be discharged for optimium operating life (e.g. as much as possible my li-ion's always stay between 4.05v and 3.75v)

If the MH-C808M is hard on them, is the stock eneloop 1-4 charger optimal?

 

[VidPro]

deep discharge for ni-mh cells is 1v -.9v according to the manufacture specs stuff, for eneloops it is the same.

life isnt maintance free eneloops should be charged yearly (its in the manual) they also will get some "voltage depression" from long time non use, a single correct discharge cycle helps that.

the MH-C808M has a "soft mode" it works awesome

there are more than one type of enloop charger, i wouldnt call thier alogrythm "best" but they say the eneloop is not "warrenty" without using them. there are better chargers, and there are certannly worse chargers than the eneloops own charger.
myself i usually want one that does a simple discharge too, so i can get a single full (within spec) discharge prior to charge on cells not in use as often.

 

[Linger]

Off the chager they still seem less then alkaline aa's.

1)Shouldn't be. There is a cycle life for all rechargables, right? Still, eneloops should be outpowering alkalines. Try a run-time test yourself. Put alkalines in whatever it is and keep a stop watch going when-ever it's in use. When it the alkalines fail, switch to your eneloops and repeat the test. You should surpass the alkaline run time, come here and post, and keep using the eneloops off the same charge for some time. YYMV.

OR check out any of selfbuilt's AA flashlight reviews, in them is included comparison of different lights with alkaline, then with eneloops for output and runtime. Eneloops offer superior performance in all low - mid - high drain applictions, with alkalines only notable in very low drain uses.

2) i'm sorry i'm not familiar with your charger. Does it shut off after full charge? With the cells seeming to overheat on you, and the over night charge, it sounds like it's not terminating. The stock charger that came with my first set of eneloops is ~1h charge.

Vidpro,
thanx re: discharge to 0.9v
Heh, I haven't even owned them for a year. I'm keep adding new ones to rotation (marked by batch) so I use them weekly if not monthly, then recharge

seems that also answers my other questions, as two low-voltage cut offs leave me with 0.9v cells so it seems like they're cycling properly through regular usage.