AA NiMH batteries top-up

EOS Man · 24th of October 2007 (Wed)

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 · 25th of October 2007 (Thu)

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

gasrocks · 25th of October 2007 (Thu)

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 · 25th of October 2007 (Thu)

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 · 25th of October 2007 (Thu)

I have found that the Energizer 2500 rechargeables work great!

asysin2leads · 26th of October 2007 (Fri)

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. · 26th of October 2007 (Fri)

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 · 27th of October 2007 (Sat)

http://www.batteryspace.com/

Raymate · 27th of October 2007 (Sat)

Quote:

Originally Posted by 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?

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.

24th of October 2007 (Wed)	#1
EOS Man Happy Lucky 888 EOS Join Date: Feb 2007 Posts: 644	AA NiMH batteries top-up 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? __________________ My EOS Gearlist

25th of October 2007 (Thu)	#2
Jon Moderator Cocker Spaniel Mod Join Date: Jun 2004 Location: Kensington, MD USA Posts: 65,125	Re: AA NiMH batteries top-up Yes, you can "top off" NiMH - unlike NiCds they don't have a "memory effect". __________________ Jon ---------- EOS, Powershot and Domke - it doesn't get any better than this! T90 and stuff \| F-1n, New F-1, FTb and more stuff out on loan Cocker Spaniels Maryland and Virginia activities *DC Cherry Blossoms* Image Posting Rules and Image Posting FAQ Report SPAM, Don't Answer It! (link) PERSONAL MESSAGING REGARDING SELLING OR BUYING ITEMS WITH MEMBERS WHO HAVE NO POSTS IN FORUMS AND/OR WHO YOU DO NOT KNOW FROM FORUMS IS HEREBY DECLARED STRICTLY STUPID AND YOU WILL GET BURNED.

25th of October 2007 (Thu)	#3
gasrocks Cream of the Crop Join Date: Mar 2005 Location: Portage, Wisconsin USA Posts: 12,491	Re: AA NiMH batteries top-up 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? __________________ GEAR LIST http://photography-on-the.net/forum/...&postcount=842

25th of October 2007 (Thu)	#4
Jon Moderator Cocker Spaniel Mod Join Date: Jun 2004 Location: Kensington, MD USA Posts: 65,125	Re: AA NiMH batteries top-up 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. __________________ Jon ---------- EOS, Powershot and Domke - it doesn't get any better than this! T90 and stuff \| F-1n, New F-1, FTb and more stuff out on loan Cocker Spaniels Maryland and Virginia activities *DC Cherry Blossoms* Image Posting Rules and Image Posting FAQ Report SPAM, Don't Answer It! (link) PERSONAL MESSAGING REGARDING SELLING OR BUYING ITEMS WITH MEMBERS WHO HAVE NO POSTS IN FORUMS AND/OR WHO YOU DO NOT KNOW FROM FORUMS IS HEREBY DECLARED STRICTLY STUPID AND YOU WILL GET BURNED.

25th of October 2007 (Thu)	#5
i2iSTUDIOS Senior Member Join Date: Feb 2004 Location: Cincinnati, Ohio Posts: 1,009	Re: AA NiMH batteries top-up I have found that the Energizer 2500 rechargeables work great! __________________ i2iSTUDIOS.com My Blog D800 D3

26th of October 2007 (Fri)	#6
asysin2leads I'm kissing arse Join Date: Dec 2006 Location: Lebanon, OH Posts: 6,317 IMAGE EDITING OK	Re: AA NiMH batteries top-up 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. __________________ Kevin Gear List \| 7M Photography \| Sports Galleries \| My Facebook \| Ohio POTN Facebook \| Custom White Balance \| Ohio POTN Google Calendar

26th of October 2007 (Fri)	#7
Rudy M. Member Join Date: Feb 2007 Posts: 489	Re: AA NiMH batteries top-up 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. __________________ Rudy M.---Thanks to this site, I'm learning something new all the time!

27th of October 2007 (Sat)	#8
tunin Senior Member Join Date: May 2007 Location: New York, NY - Medjugorje, BiH Posts: 1,128	Re: AA NiMH batteries top-up http://www.batteryspace.com/ __________________ I am not young enough to know everything. O.W. www.medjugorje.net * Amateur tools *

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