Solenoid dual battery system

It would depend on how it is switched. The best is to switch it with the accessories position of the ignition so that it is off when the key is removed so your fridge etc can keep running off the aux and leave the main fully charged (this can be done by tapping into the wiper motor harness). You don't want the solenoid to stay engaged as it will keep the batteries linked and the fridge etc will drain both as well as the solenoid drawing the batteries down (Approx 0.3 to 0.6A /h). The advantage of the accessories position is that it is normally off during cranking so that the aux is not linked to the main during cranking.

I can email you a instruction sheet if you wish.

Most batteries will charge together with no problem if they are similar in size.

Regards

Derek.

Hi Poida,

I purchased a unit from Supercheap for $99.00.

It came with heavy duty wires to connect the 2 batteries and a control device which disconnects the aux battery from the starting battery when the voltage in the starting battery drops below 11.5 and will not reconnect the aux battery till the voltage in the starting battery gets up to 12.5 volts or there abouts.

It also comes with a good set of instructions.

It is in a neat little package, solenoid and activation circuit, and I thought it was excellent value for that money.

I have been using it for about a year now, 5 days a week at least and I am very pleased with it.

Derrick from ABR might have a better quality unit so I would seek his advice, or where offered, consider it in depth. It is free advice and is worth a whole lot more than you pay for it.

Regards,
Gazal.