Is this bad for my rechargable AA's?

Sagitta · 05-28-2011, 05:51 PM

Basically I own two chargers - a quick charging Polaroid charger and a more expensive Energizer brand that takes 8 hours or so to go from flat dead to fully charged.

I was lazy and allowed myself to run out of charged batteries a while back (and I own 5 or 6 sets of 4....) so I slapped some in one charger, and some in the other, and plugged them both in.

The Polaroid charger read 'ready' after only an hour or so, while the Energizer was working its set for another 6 according to its readout. Impatient, I yanked the batteries from each charger and swapped them. The 'charged' batteries that were in the Polaroid still read as having 2 hours to go when I first put them in, but the Energizer 'topped off' the batteries in about 30 minutes. I was able to go from dead to fully charged in less than 2 hours this way.

SO.

My question is will this shorten the life of the batteries enough to warrant my caring about it or is this safe enough to do if I'm in a hurry?

aleonx3 · 05-28-2011, 06:01 PM

If you use the Eneloop or Duraloop AA batteries, you don't need to rush... you can always pre-charge them with a few sets so they are ready to go for a gig. I prefer not to use the so-call 'fast' chargers since they 'may' (no scientific proof) shorten the life of these batteries.

K57XR · 05-28-2011, 06:44 PM

Rapid chargers in general are bad for rechargeables, as the high current charge rate required to complete a “fast charge” causes the battery to heat up and shorten its life. Some rechargeables are even hot to touch right out of a rapid charge cycle.

I don’t think you killed your batteries by doing what you did but I wouldn’t recommend doing it often. You can always carry a set of new Lithium batteries (which will get you >1000 shots on a K-x) as back up in case you get “lazy” again.

hcc · 05-28-2011, 07:30 PM

+1 with k57xr. Fast charge is bad for rechargeable batteries...

Plan ahead and always recharge your batteries after use.

wlachan · 05-29-2011, 02:50 AM

NiMH can be killed by heat during charging or overcharge. Otherwise, you can do whatever you want.

Sagitta · 05-29-2011, 09:44 AM

OK, the fast charger is basically an emergency backup for me from now on.

Thanks for the advice everyone!

epqwerty · 05-29-2011, 01:10 PM

Using a slow charger is definitely better than a quick charger. I've used a quick charger once before and it gave very inaccurate results. The battery would say full on the meter but the camera would drain it after a couple of shots.

05-28-2011, 05:51 PM	#1
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081	Is this bad for my rechargable AA's? Basically I own two chargers - a quick charging Polaroid charger and a more expensive Energizer brand that takes 8 hours or so to go from flat dead to fully charged. I was lazy and allowed myself to run out of charged batteries a while back (and I own 5 or 6 sets of 4....) so I slapped some in one charger, and some in the other, and plugged them both in. The Polaroid charger read 'ready' after only an hour or so, while the Energizer was working its set for another 6 according to its readout. Impatient, I yanked the batteries from each charger and swapped them. The 'charged' batteries that were in the Polaroid still read as having 2 hours to go when I first put them in, but the Energizer 'topped off' the batteries in about 30 minutes. I was able to go from dead to fully charged in less than 2 hours this way. SO. My question is will this shorten the life of the batteries enough to warrant my caring about it or is this safe enough to do if I'm in a hurry?

05-28-2011, 06:44 PM	#3
K57XR Veteran Member Join Date: Feb 2011 Location: Colorado, USA Posts: 830	Rapid chargers in general are bad for rechargeables, as the high current charge rate required to complete a “fast charge” causes the battery to heat up and shorten its life. Some rechargeables are even hot to touch right out of a rapid charge cycle. I don’t think you killed your batteries by doing what you did but I wouldn’t recommend doing it often. You can always carry a set of new Lithium batteries (which will get you >1000 shots on a K-x) as back up in case you get “lazy” again. Last edited by K57XR; 05-28-2011 at 06:51 PM.

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05-28-2011, 06:01 PM	#2
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	If you use the Eneloop or Duraloop AA batteries, you don't need to rush... you can always pre-charge them with a few sets so they are ready to go for a gig. I prefer not to use the so-call 'fast' chargers since they 'may' (no scientific proof) shorten the life of these batteries.

05-28-2011, 07:30 PM	#4
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,005	+1 with k57xr. Fast charge is bad for rechargeable batteries... Plan ahead and always recharge your batteries after use.

05-29-2011, 02:50 AM	#5
wlachan Veteran Member Join Date: Sep 2006 Location: Canada Photos: Albums Posts: 2,625	NiMH can be killed by heat during charging or overcharge. Otherwise, you can do whatever you want.

05-29-2011, 09:44 AM	#6
Sagitta Veteran Member Join Date: Feb 2011 Location: Maine Photos: Gallery Posts: 3,081 Original Poster	OK, the fast charger is basically an emergency backup for me from now on. Thanks for the advice everyone!

05-29-2011, 01:10 PM	#7
epqwerty Veteran Member Join Date: Dec 2009 Location: Ontario Posts: 550	Using a slow charger is definitely better than a quick charger. I've used a quick charger once before and it gave very inaccurate results. The battery would say full on the meter but the camera would drain it after a couple of shots.