Rechargeable AA batteries

[victorzamora]

Not to hijack the thread, but I was recharging my batteries about a week ago (EverReady Energizers as pictured above) and I noticed that they were warm to the touch. This is the first time that I had noticed that they were getting warm while recharging. Is this normal, or is it the first indication that maybe I should replace them before the next trip. (I don't want to be on a live aboard w/o functioning batteries for my strobes.)

Thanks

Yup, it's totally normal. Faster charging and discharging means hotter cells.

 

[DivingKDawg]

I just got these red Eneloops. Ni Mh. The package specifically says "Do not use in underwater flashlights or any airtight device." Did I get the wrong batteries ?

 

[fmerkel]

That's been brought up before. Pretty much a liability disclaimer.
FWIW when saltwater gets into a battery in a confined space that has a lot of energy and high discharge capability it is potentially capable of creating enough heat to make steam or off gas H2. Enough pressure build up and it can possibly rupture a device. Not common, but I've heard it happening. My wife left a UK400R (18W, 4xD-cells) dive light on accidentally after a dive. At the end of exhaustion NiMh can off gas H2. It blew the light head off. Batteries charged back up fine, and the light head threads weren't damaged. The whole system went back to diving for many more years.

 

[NAM001]

Any recommendations? I have 2 Ikelite DS51 strobes and want to get rechargeable batteries.

do you need 1.5 v AA batteries If so let me know and I will get you a link.

The ones I use are KENTLI ,,,,,,,,,,I think

1.5v ferus ion something like that.

 

[jseyfert3]

Eneloops come in white and black (pro). The latter have more recharges available (2100 vs 500), the latter have more power available (2550 vs 2000 mAh). I use the black; I figure at 1 charge per half-day of diving, that is several years of use.

Half backwards. The pro have a higher capacity (2550) but only 500 recharges. The regular have lower capacity but 2100 charges. You trade life for capacity in the pro version.

 

[jseyfert3]

Yeah, in the end, I think rechargeables in any device where you expect to put the battery in and leave it for weeks or more is not the best idea and doesn't really save you very much money at all, either. If you expect to take them out to recharge every day or two, then yeah.

I use rechargeables in my dive lights and strobes, but not my Perdix. For dive lights and strobes, I take the batteries out at the end of each day and then I charge them the night before I plan to use them again.

A set of Eneloops is what, 4-5x the cost of a set of brand name alkaline batteries? So in five uses they pay for themselves, in another five you pay for the charger and it's all saved money from there.

I can leave me Eneloops in my (land based) Canon flash for months and pick up the camera and start snapping off pictures. Eneloops self discharge so slow it's negligible (they advertise 70% capacity remaining after 5 years - just checked, now they say 10 years). I use Eneloops in my wall thermostat, TV remotes, pocket flashlight. Trust me, self discharge isn't an issue at all.

Get the regular (white) Eneloops unless you NEED the 25% higher capacity of the black pros (e.g. you have to run slightly longer between charging). The pros get higher capacity by trading off other factors. Compared to the regular ones, the pros have 75% less cycle life (only 500 instead of 2100 recharges) and higher self discharge (80% capacity remaining after 1 year vs 70% remaining after 10 years).

 

[tursiops]

Half backwards. The pro have a higher capacity (2550) but only 500 recharges. The regular have lower capacity but 2100 charges. You trade life for capacity in the pro version.

Ooops.Thanks.
And then there are green ones and blue ones and red ones.......which I *think* are all like the white ones, but I am not sure.

 

[DivingKDawg]

Ooops.Thanks.
And then there are green ones and blue ones and red ones.......which I *think* are all like the white ones, but I am not sure.

Mine are red

 

[stuartv]

A set of Eneloops is what, 4-5x the cost of a set of brand name alkaline batteries? So in five uses they pay for themselves, in another five you pay for the charger and it's all saved money from there..

I could be wrong, but I think a normal alkaline lasts longer than even an Eneloop does on one charge. So, it probably takes more than 5 uses to pay for itself. Anyway, 5 regular alkalines would last me 2, maybe 3, years for my Perdix. The SAFT batteries last a lot longer.

No big deal either way. I personally don't mind the extra "long term" expense of using an akaline or a SAFT in devices that only need a new battery once or twice a year. I don't have any hard data to support this, but my feeling is that I'd rather trust a SAFT that has sat around in my Perdix case for a year than to trust even an Eneloop that has sat around in the case for 6 months. It's a pretty minor thing, I admit. I really don't think either approach is "bad".

 

[fmerkel]

NiMh vs. Alkaline
Use of NiMh depends a LOT on exactly WHAT you will use it in, and HOW you will use it (amp draw). For VERY low draw applications you will be better off with alkaline if you want max time, but at the risk of 'alka-leaks'. I've had a number of devices destroyed by leaking alkalines. I don't trust them anymore.The more expensive the device, the less I will use them in that application.

If you are drawing over 0.2a, and all strobes draw well over that when charging, you are better off with a quality NiMh. It just plain works better, lasts longer in use, and does not risk leaking cells.