Topic: Battery question

[Karl]

I have a general question about rechargeable batteries.   Say that you use a device daily, and let's say it could go for 5 days on a single charge.  Is it better for the batteries to recharge every night, or once every 5 days? 

And then, would it be different for different types of rechargeables?

[dnsacks]

depends on the battery type.  SLA (sealed lead acid) batteries HATE to be fully/deeply discharged and should be topped off as frequently as possible.  NiCad batteries don't take well to being partially discharged and then recharged -- they llike to be pretty fully discharged before being re-charged (or they develop "memory effect") NIMH and Li-ion are somewhat inbetween, but it's generally a good idea with these to NOT recharge them if they're real close to fully charged.

If this doesn't help, give us some more specific info on the batteries youuse

[Karl]

ALL batteries hate to be deep discharged.  Many players/recorders that use lithium or NiMh generally don't have that problem, because they have protection circuitry that shuts off power when the batteries get too low.  But the batteries themselves still have the problem.

[dnsacks]

Karl:

Agreed with Lithium batteries, but I thought nimh batteries actually "liked" being deep discharged from time to time -- isn't that what "conditioning" a nimh battery does?  (i.e. fully discharge and then recharge it?)

Actually, a bit of research showed that "deep discharge" is a matter of degree -- never discharge one below 1v per cell or risk permanent damage. 

So, I'll rephrase -- never use rechargables with a device like a flashlight that can allow them to fully discharge, as discharging a 1.2v nimh to below 1v can cause severe damage to the cell.  However, if a nimh will no longer hold a charge/run like it used to, a "conditioning" discharge in a charger that's designed to charge nimh batteries (maha c204f) could work wonders on the batteries.