AA NiMH batteries top-up

[EOS Man]

I charge my set of AA NiMH batteries in a 6 hour Sony charger - and that is a freakin long time. Is it possible to 'top up' AA batteries like we can do with li-ions? Like if the batteries are down by 1/3 juice, then would it take 2 hours to top up or need to go through another 6 hour charge cycle?

[Jon]

Yes, you can "top off" NiMH - unlike NiCds they don't have a "memory effect".

[gasrocks]

Thomasdistributing.com is the best place I have found for batteries, chargers and info. Sounds like a very long time to me. Maybe a better charger?

[Jon]

Fast chargers tend to get the batteries hot - and that breaks the electrolyte down faster, so the batteries don't last as long. It's a tradeoff. Generally, I won't use a fast charger unless I need to get a set charged ASAP. I carry enough to get me through the day and have several recharging at night or the next day.

[i2iSTUDIOS]

I have found that the Energizer 2500 rechargeables work great!

[asysin2leads]

I have the Duracell rechargables (black and green) that are 2650 mA and they seem to do very well. I carry a charger with me and have 24 batteries with me just in case. I've ran out of juice once and there won't be a twice. I missed some great shots by running out of battery.

[Rudy M.]

6 hours isn't bad for 2500mAH cells--that's 500mAH of charge per hour with some top-off, assuming dead cells. OTOH, if you are topping off and the charge time lasts 6 hours, you need a better, SMARTER charger. You would be overcharging your cells. Overnight, slow charging is best for your cells. Fast charge only when you need to. As a rule of thumb, if a NiCd cell could get cycled over its useful life a 1,000 cycles, then an equivelent NiMH cell should be good for about half that, and a Lithium Ion cell about half that. Each time you use the battery, then charge it, even if "topping off", it is considered a cycle. You will get a very short life from your Lion camera packs if you keep topping off--but at $12.00 a pack from Sterlingtech--who cares. In typical consumer applications, it is highly unlikely NiCd cells would develope a "memory" effect--I have some NiCd packs that are about 8 years old that still function fine--I just run them down every 10 cycles or so.

[tunin]

http://www.batteryspace.com/

[Raymate]

Thomasdistributing.com is the best place I have found for batteries, chargers and info. Sounds like a very long time to me. Maybe a better charger?

Second Thomas Dist...

Get a quality charger that can do different charging speeds then you can do whatever you like. Like the Powerx or the Lacrosse

But slower is better, if you want to fast charge make sure you also do some slow ones as well.