MULTIPLE BATTERIES IN CARS

Connection as shown on the attached drawing.

If multiple batteries are required to power consumers used while the engine is not running (a fridge, TV set, etc.), the AH/RC of the battery (batteries) must be calculated so that the battery voltage does not drop much below 11 Volts before the engine needs to be started (for simplicity, and if possible, preference should be given to single battery with sufficient AH/RC).

With reference to ALTERNATOR RATING IN CARS above, 20% must be added to the alternator rating figure for every additional battery (or a battery with substantially higher AH/RC than standard).