drivesafe wrote:

Hi britindus, it depends on how you want to use your winch as to how you set up your dual battery system.

If you are only going to use your cranking battery, most controller will isolate as soon as the voltage drops once you start to winch but you may need to look at the operation of what ever type of controller you are planning to fit.

Many DBS controllers that are fitted with an optional manual switching set up to allow jump starting and will only tolerate very short periods of high current operations but are not suitable for using the same set up for winching and MUST be isolated in some way.

On the other hand, if you intend to use both batteries while winching then you will need some form of DBS controller bypass, again as very VERY few DBS controllers can handle the 200+ amps for prolonged periods of time.

The now accepted best practice for using a winch is to have the motor on high idle and winch for 60 seconds and rest for 90 seconds, then repeat.

Having the motor in high idle while resting give the battery(s) and chance to get some of the bulk charge replaced and lowers the chance of damaging the battery and continually provides high voltage during winching.

If you intend to use both batteries then it is necessary to fit some form of DBS Controller bypass device and the best form of bypass device is a marine battery switch, because of their high current carrying capacity.

Also if you intend to use both batteries while winching then both batteries must be cranking or dual purpose type batteries. Using a dedicated deep cycle battery for winching will guaranty a very sort operating life for any deep cycle type battery.

Again if you intend to use both batteries, you will also need to fit much thicker cables than would be necessary with a DBS set up.