IDENTIFYING A BAD BATTERY
Here's a method:
· Charge all batteries
· After one hour record the voltage of each battery, using a digital voltmeter.
· Do close to the maximum range miles
· Quickly take the voltage of each battery with digital voltmeter.
· Compare the voltages - the bad battery should be 1-2 volts lower.
· Charge the batteries again.
· Bypass the bad battery so that it is not in circuit
· Drive again and see if range increases. This confirms that you have identified the bad battery.
· Put bad battery back in circuit
· Then replace bad battery.
If you have an infrared thermometer, the bad battery will be 15-30F hotter after the first run at maximum range. This is a nice confirmation.