Barbara Mortimer writes: “I have a motorboat with three battery banks (engine, house and anchor winch) charged by the alternator via a Sterling ProSplit R.

“I also have a mains battery charger but have moved the boat to a swinging mooring so plan to add solar panels to keep the batteries topped up between trips.

“What is your advice on connecting boat solar panel chargers? Is it best to connect via the ProSplit, or should the connection be direct to one set of batteries?”

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PBO electrics expert Duncan Kent replies: “The ProSplit is only a little smarter than the run of the mill alternator charge splitter/isolator, so I’d avoid confusing it by feeding a variable solar output into it.

“Though it might work, it’s better to take the output from a solar charge controller directly to a battery or battery bank.

“Personally I’d connect it to the engine start battery. That way you will always be able to start the engine and charge the other batteries via the alternator.

“If you do this you won’t need to worry about disconnecting the solar before running the engine as they will work alongside each other without a problem.”

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