To determine the charging time of a battery at a given current is a simple matter, determined
by the Formula:-    Time to charge = Capacity/Amps. eg., to charge a 1500mah battery at a
charging rate of 5 amps, is 18 minutes.

In the formula, you get 1500mah/5 amps. Convert the mah to amps and you get
1.5amps/5amps = .3 hours.

There are 60 minutes in an hour, so multiply .3 x 60 and you get the amount of 18 minutes.

You can also use the formula to work the charging rate for a given length of time. eg. Amps
= Capacity/Time, so to charge the 1200mah battery for 20 minutes, you get 1200mah/.33
hours (20 mins), which is 1.2 amps/.33 =3.6 amps. You would have to charge at that rate for
20 minutes.

Confused? A peak detection charger comes into its own here as it does it all automatically. It
is easy to cook (overcharge) your battery pack, and most of us do so regularly, thus
shortening the life and leading to possible Personal Disasters.