12V Supply

[cubaneight]

We are close to buying our first caravan and I'm gathering as much info as I can to be better informed.

I'd like a little more information on the issue of charging the caravan's battery from the car. Information on the 'net and in the Haynes caravan manual is very useful, but I'd be grateful of a few points to be clarified please.

When it's said that the caravan is charged from the car's alternator, I'm assuming that the battery is charged from an appropriate 12V feed direct from the car's wiring. Are the batteries used in caravans (leisure batteries?) similar in construction to a standard car battery (with the same charging criteria)or are they sealed gel types that require special constant voltage charging?

Am I right in thinking that protection relays are used to prevent a massive current draw from the caravan's battery when the cars's starter motor is used?

Thanks

kevin.

 

[Damian]

Kevin, the battery charging from the car is done through the 12S (or Grey)or 13pin socket, as is fridge operation on 12v.

The feed from the car is via a relay which only switches over to providing power to the battery when the engine is runing and the alternator producing around 14v, so there is never any drain on the leisure battery when starting the car, nor does any power from the leisure battery go back thorugh the 12S to power anything in the car.

Leisure batteries are similar in construction to car batteries but they ar emade to withstand long discharge rates, unlike a car battery which is designed to allow massive amp draw for a short period of time.

It is unlikely to damage a leisure battery when being charged from the car, and as with all batteries they need charging to 14.8v to maintain their peak performance

 

[cubaneight]

Kevin, the battery charging from the car is done through the 12S (or Grey)or 13pin socket, as is fridge operation on 12v.

The feed from the car is via a relay which only switches over to providing power to the battery when the engine is runing and the alternator producing around 14v, so there is never any drain on the leisure battery when starting the car, nor does any power from the leisure battery go back thorugh the 12S to power anything in the car.

Leisure batteries are similar in construction to car batteries but they ar emade to withstand long discharge rates, unlike a car battery which is designed to allow massive amp draw for a short period of time.

It is unlikely to damage a leisure battery when being charged from the car, and as with all batteries they need charging to 14.8v to maintain their peak performance

thanks for the quick reply. The 14V voltage sensing relay, I now realise, is the key to it - very clever!

Cheers.

Kevin.