Question re trickle charge NiMH’s

Hello,
I've been leaving my NiMH AA's on trickle charge, but have got to wondering if that decreases their life? I've got a medium quality charger that charges them relatively fast (2 hours or so for AA's) and then switches back to a trickle charge. I know NiMH batteries only have a limited number of charge/recharge cycles, but does permanently leaving them on trickle charge make them last longer, or wear out quicker?
What's the best way to store and prolong my NiMH battery's life?
Thanks.

thei said:

Hello,
I've been leaving my NiMH AA's on trickle charge, but have got to wondering if that decreases their life? I've got a medium quality charger that charges them relatively fast (2 hours or so for AA's) and then switches back to a trickle charge. I know NiMH batteries only have a limited number of charge/recharge cycles, but does permanently leaving them on trickle charge make them last longer, or wear out quicker?
What's the best way to store and prolong my NiMH battery's life?
Thanks.

Click to expand...

1. Don't leave them on trickle charger indefinitely

2. Don't discharge them so completely far to the point of over cells going into reverse polarity

Handlobraesing said:

1. Don't leave them on trickle charger indefinitely

2. Don't discharge them so completely far to the point of over cells going into reverse polarity

Click to expand...

In that case, how often should I charge them? If I take them off the trickle charger, they'll start self-discharging, and if I want to have them fresh for use, I'll need to charge them, so how often should I recharge them?
Yeah, I know that sounds very anal… but I might as well ask.

Hello Thei,

I agree that it is not best to leave your cells on trickle charge all the time.

It would be better if you had just enough cells to last you a month. Cells work best when they are used and seem to develop more problems when they are stored. A one month turn around, with a few primaries for emergencies, is a good interval.

If you have lots of cells, you will have to do some maintenance. Schulze recommends discharging your cells for long term storage at 1 amp down to 1 volt per cell. Then you do a charge/discharge cycle every 30 days to keep them fresh. The other end of the spectrum is that at room temperature a cell will have self discharged down to around 50% in 90 days, so a 90 day charge interval should keep you above 50% all of the time. If you let the cells self discharge all the time, you may find that it takes a few charge/discharge cycles to bring them back up to full capacity.

Tom