What brand of batteries do you have ?
how old - stamped on Battery posts ?
Do you own a digital Volt meter, if not get a DIGITAL Meter.
Take Voltage reading across entire pack , + on Battery #1 to - on Battery #6
If pack Voltage is low , then measure each Battery
If you have a battery Hydrometer then check cells on weak batteries.
Here is a chart to help .
http://www.buggiesgonewild.com/elect...-readings.html
Post results back here
PS do not POST same ? more than once