NiMh Rechargeable Batteries

[jebatty]

I've been looking at various brands and capacities, and I was on a photo site that included a detailed review of the Sanyo Eneloop brand which indicated that these hold their charge much longer than others and have better performance as well, including low temp performance. It is time to replace my rechargeable AA's. What experience by others on these or other brands? Or other battery chemistry for AA's?

 

[semipro]

About 4 years ago I bought a package deal with the Eneloops and the recommended charger as well as some adapters that let you use AA where Cs or Ds usually fit.
By far I've had a much better experience with the Eneloops purchased online than I've had with the Ray-o-vac or Evereadys bought at local retailers.
I'd probably buy the Eneloops again when these die.

 

[woodgeek]

Also had good luck with the eneloops, seem better than the sanyo ones that came free with my charger.

 

[jharkin]

I use a lot of Eneloops - I have a bunch of loose AAs and their charger that I use in small household items like remote controls, etc. I also use custom made packs in my R/C airplane transmitter gear. The eneloop strength is low self discharge... You can leave them sitting for months and still get 90% + Capacity. The cost of this feature is a high internal resistance (25 mOhm per AA if I recall) and very delicate internal structure which does tolerate fast discharge/charge or rough/high vibration environments.

If you can charge overnight,want to be able to charge a bunch and leave them sitting around and are using them in flashlights, remotes, etc they will be great.

If you want to use them in something like a power tool you will kill them fast. If you want to fast charge (under 2 hr) you will kill them fast. In that case try regular Sanyo NiMH or better yet old fashion NiCads.


The Eneloop brand 4 cell charger will recharge a set in 4hr which is about as fast as you want to do with these cells and still get decent lifetime from them. An overnight (10-16 hr) charger will give you a few more years life.


[Edit]
I buy a lot of my household rehcargables at the same sources I get RC batteries.

http://www.radicalrc.com/category/NiMH-Single-Cells-69
- Scroll to the bottom for Enelopp single AAs. Better prices to buy in multi placks elsewhere.
- If you need a high dishcharge rate cell look in the middle of hte page for the 1650mAh HR-AAU cell/
- Or for something that takes a lot of abuse get a Sanyo AA Nicad (http://www.radicalrc.com/category/NiCad-Single-Cells-71 top of page) Those will tolerate discharging at a few amps and 30 minute recharge cycles.

 

[Sprinter]

It depends on the application. Eneloops have a much longer self-discharge rate, but less capacity as a trade-off. Depending on the variables, it seems like around 3 months in the device is about the point where it becomes better to use eneloops or regular, higher capacity. That is, if the battery is going to sit in, for example, a seldom used DVD remote control box for 3 months or more, then an Eneloop would be the better choice. But if it's in a device where it will have to be charged pretty soon anyway, then you may as well enjoy the extra capacity of a regular one, especially if it's a high discharge device like jharkin said.

Personally, I like Eneloops for the long shelf life. I can just take one out of the drawer and know it's pretty fresh and they seem to have enough capacity for most household applications. But there are good reasons to use regular, higher capacity ones, in some applications.

 

[jebatty]

I didn't realize I had 2 Eneloops, not knowing they were any different from other NiMh batteries. I had put them in my camera, which sits idle most of the time, and now have noticed that the batteries last much longer than my other rechargeables. Based on info on the Eneloops, the slow self-discharge/voltage loss of Eneloops over regular NiMh rechargeables appears to be the factor in this longer battery life.

I was at Cosco on Monday, and saw that they had 10-packs of AA (1900 mah) for $20. Seems like a good price.

 

[ihookem]

I'm going with Eneloops cause the Rayovac and Energizer AA I had no luck with them at all. So far the 20 eneloops I've bought are all good. They are cheeper to boot if ya get them at Cosco, 2 bucks each is cheap. They last plenty long in my trail cams.