Batteries and Mila amps per hour

[chikenman31]

i was just wondering if using a battery of the same size, like a nimh c cell battery, but of different Mila amps per hour to connect it to a pre-configured battery, would it affect how long the battery would last if there were a couple batteries of higher Mah hooked up in series/ parallel connection.

Say i had a couple batteries of 2000 Mah in series/parallel.
If i needed just one more battery to increase the voltage from the pre-configured volts of 6.8 to 8 volts,
would a battery of the same voltage but of decreased Mah, last as long as the batteries of 2000 Mah.

sorry if i wasn't clear enough

[tom61]

The voltage will drop as each cell gets low. The less than 2000mAh battery would limit your run time.