Re: [Amel Yacht Owners] DC cable sizing for larger charger
Bill Kinney <greatketch@...>
There isn’t a hard and fast simple answer to this question, but here are the things to consider.toggle quoted messageShow quoted text
For this application, the normally recommended voltage drop would be 3%. I am guessing that the run of wire from the charger to the batteries is 25 feet.
Pushing 100 AMPS through 3 AWG wire for this distance will give a voltage drop of about 1 volt or 4% of 24 volts.
To drop this number down to below 3% would take 1 AWG wire (0.62 volts/2.6%)
To give you a feel for the design criteria used in the original installation, pushing 50 amps through 3AWG wire 25 feet would give a drop of 0.5 volts or 2%.