quick battery question

[midwestdvr]

Do you completely deplete you rechargeable AAs before recharging or do you just charge it? Been doing both but I'd like to know the right way before I damage my batteries. Thanks.

midwestdvr

 

[devolution365]

Depends on what type of rechargeable batteries you are using.

See: http://is.med.ohio-state.edu/policies/battery.htm

or even better: http://www.batteryuniversity.com/partone-23.htm (4th question down, but the site has pretty much everything you'd ever want to know about batteries.)

 

[midwestdvr]

Depends on what type of rechargeable batteries you are using.

See: http://is.med.ohio-state.edu/policies/battery.htm

or even better: http://www.batteryuniversity.com/partone-23.htm (4th question down, but the site has pretty much everything you'd ever want to know about batteries.)

Thanks. That second site was exactly what I needed. BTW, I like your icon. Wouldn't mind being able to breath underwater...

midwestdvr

 

[justleesa]

I remember that I somewhere read that it isn't good to run a battery all the way down, can't remember they why though.
After a dive day mine go back on the charger. Right now my batteries are 2 years old and still going strong. I use them in my surface and UW cameras and you can pretty much say they get used everyday. I get 4+ dives with the camera batteries and I can get 8+ dives out of the ones I have in my strobe.

 

[pants!]

Running a battery all the way down depletes its life. This applies to all chemistries I believe.

NiMH is not susceptible to the memory effect so do not run them down periodically.

 

[justleesa]

Running a battery all the way down depletes its life. This applies to all chemistries I believe.

There you go, I knew someone that has a better memory than I do will come along...Thanks pants!

 

[ChillyWaters]

Running a battery all the way down depletes its life. This applies to all chemistries I believe.

NiMH is not susceptible to the memory effect so do not run them down periodically.

I read somewhere about the memory effect being mostly myth. The batteries actually had to be run down to the exact some level repeatedly, which is unlikely to occur for consumer applications.

Again, this is what I read a while ago. I really don't know about the matter personally. But you are right, there is supposed to be no memory effect with NiMH, so don't worry about intentionally running them down.

- ChillyWaters

 

[Orlando Eric]

Give them to your wife.

 

[Charlie99]

I read somewhere about the memory effect being mostly myth. The batteries actually had to be run down to the exact some level repeatedly, which is unlikely to occur for consumer applications.

1. It was early generation NiCd where the chemistry wasn't as pure as modern (post 1985!) cells.

2. It was a satellite application with repeated indentical charge/discharge cycles as the satellite went into and out of the earth's shadow.

3. The "memory effect" was just a minor voltage depression, i.e. just a bump on the voltage vs. time discharge curve that didn't greatly affect energy storage.

The strength of this myth is amazing.

-------------------------------

Lead Acid / Gel cells / SLA batteries are greatly damaged by overdischarge. Irreversible chemical changes.

All of the various Lithium Ion chemistries I know of are similarly damaged if discharged below a certain voltage.

NiCd and NiMH cells can aren't damaged too badly for a full discharge and can be stored fully discharged. Their life is reduced, but it isn't a totally destructive thing as with lead acid or LiIon.

OTOH, NiCd and NiMH cells don't like to be reverse charged. Fully discharging a NiCd or NiMH battery (a bunch of cells in series) will reverse charge the weakest cell(s), thereby significantly damaging it. That's why a lot of electronics has low voltage cutoffs which shut down the system at (N-1) * 1.1V ----- that's the voltage you will have with most cells fully discharged and 1 cell just getting to the point of being reverse charged by the others in series.

 

[Dee]

Like Leesa, mine get recharged at the end of every dive day. I could probably get 4 dives on the camera batteries, I just haven't pushed it. I commonly get 6+ dives on the strobe batteries.

I think it also depends on the type of recharger you use.