extra battery

[jcys13310]

as i use loads of extras on my van, inverters extra interior lights etc etc, how would i wire up an extra battery please

[homer75]

You need to wire it in parallel to maintain 12 volts i.e. plus terminal to plus terminal and negative to negative using heavy cable.

[Eddiecurrent]

It may be a better option to use a totally separate charging method and separate the vehicle battery from the accesories battery. This would enable you to protect the vehicle's battery from running low.
To do this you would need to purchase a 'split charge' relay (available from Caravan spares shops). This will allow the alternator to charge the vehicle's battery before applying a charge to the separate battery. To wire the second battery up would require you to observe the instructions on the relay. It would be better to use a leisure battery as the second battery as they are designed to withstand the constant charge / discharge cycle that would otherwise damage a standard car battery. Obviously the accesories would be wired onto the leisure battery.

[markja]

exactly as eddie said. remember, if you wire them in parallel you drain both batteries flat if used with the motor turned off. with a leisure battery and a seperate charging system if you flatten the leisure battery the vehicle battery is not affected (as long as everything is wired up corectly )
and as a bonus, if the leisure battery is in a sensible place it can be used to help jump start the standard battery if it's a bit weak/sluggish one morning.
leisure batteries are more expensive but worth it. i know 'cos i have a campervan with this set up.

[homer75]

Are we talking about a van here or a mobile home ? extra battery would be my option on a working van - no need for rocket science on drainage and all that jazz