Monday, Feb 17, 2020 at 09:45
Most winch setups are across the cranking
battery, so if you flatten the winch
battery you can't start the car anyway unless you have another
battery.
Many using
winches have alternators around the 100A output, you only get 100A with the alternator at max output and this is not going to occur at idle when most winching is done as the alternator can only produce around 60% of its max output at idle. In the case of a 100A alternator allowing around 30A to run the vehicles electrics it only leaves another 70A with the alternator at flat chat, not much difference to the charger. With the alternator at idle probably around 30A.
Race the engine you say, hot under bonnet temperature with motor racing means little cooling air for the alternator, old type alternators without temperature compensation could overload and burn out, newer alternators will heat up and reduce their output to protect themselves so even less current becomes available for winching.
How you set it up is up to the individual, personally I have the winch connected to the aux, the aux is charged via an isolator that has overload protection built into it, it also isolates the aux from the main during wincing to prevent the winch draining the cranker. Not much point having a winch if can't start the motor anyway.
The OP setup is interesting, depending on how the DCDC charger is setup it may continue to charge the ignition
battery even if the engine is not running so may actually be a better setup than most use anyway.
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