Battery charging time question for electronics people

[MelancholyMutt]

Hey all,

I got some new batteries (Ni-Cd and Ni-MH) for a piece of electronics and I've got to figure out something...

Charger #1 puts out 200 milliamps per hour and takes 6 hours to charge fully.

Charger #2 puts out 500 mah, but does not have charging time information.

THC induced logic tells me that it takes then, 1200milliamp/hour to charge the battery... 1200, then divided by the 500 of charger #2 is 2.4 hours or 2 hours and 24 minutes....

Is that correct or is that too simple?

 

[Chris "Anagarika"]

it's that simple for general purpose

battery charging = energy.

electricity energy is: volt x ampere x time lapsed = energy (remember kilowatthour = kilo volt ampere hour?) you pay your electricity bill by kwh and not by the kw (capacity / power output available, determined by the ampere, thus the incoming line fuse/breaker capacity)

in your equation, the voltage is fixed, so ampere and time is the variable determining energy stored.

hope that doesn't confuse you

HOWEVER, some charger has the fast charging (pumping slightly higher voltage and ampere) for initial chargin, with ripple effect built in to 'shake' the battery for maximum filling the cells. that alters the equation, but i believe only a bit.

 

[MelancholyMutt]

Thank you Chris