Two Batteries

[Culagh]

Hi

I'm in the lucky position to have two new Leisure Batteries. As I'm contemplating buying a Jockey Wheel caravan mover I was wondering if I could link the two batteries together, on the caravan, and therefore give me double the 12v power available, if I needed it.

 

[Murdan]

If you link 2 batteries together the output will be 24V

 

[Viking1]

Hi Jim

I seem to thick that it was in the the mag so mouths ago.

Mark

 

[Damian]

Jim, if you link the batteries parallell, + to +, - to -, then you will have 12v but double the amps available, assuming the batteries are the same amp/hr rating.

If you wire in series, then you keep the same amps but increase the voltage to 24 v

 

[Tankie]

I have always been told not to use 2 batteries together. Its far better to use them singularly and keep the one not in use on charge in the car and just change them over when required.

Tankie

 

[rob_jax]

Jim,

You need to keep both batteries charged (once a month at least or a solar panel trickle charge into both) otherwise you'll soon have at least one dead battery.

Even the real caravan movers - that drive the caravan wheels - aren't that hungry on battery power - and a jockey wheel mover is lower in power usage.

If the two batteries are identical in power rating, then yes you can link them in parallel, but charging is a problem - they MUST be charged independently or (high current) blocking diodes need to be fitted

Best advice - use them one at a time

Robert

 

[Dave_374230619]

This topic has been discussed many times, with extreme views of DONT do it, to you CAN do it.

I have had two 110amp batteries (purchased together and of the same make, VARTA) wired together for nearly two years using short lengths of heavy duty cable. The advice was given to me by the owner (and a friend of mine) of a battery supply shop. Thats all he sells (South Yorkshire Batteries). I did this because I have the need for mains supply (via a 1000w inverter) but only camp on rally fields and do this nearly every weekend of the year. The batteries get charged by one of those 'inteligent' chargers (wired direct to the batteries) from Monday to Friday then the van is out over the weekend then back on charge. I can only speak about my experience, but I have never had any trouble with this set up at all.

 

[EmmanuelMuldoon]

I would never connect two high power batteries in parallel, if one has a different terminal voltage than the other, then a very large current will flow, which could easilly result in a fire and/or burning out the cables. Thats one reason "blocking" diodes re used.

I once saw a film (yes film, before the days of video tape)to demonstrate the power of lead acid batteries. IIRC it was a 50V supply as used in telephone exchanges. They put this bank of cells in a brick building and put a dead short on the bank with a contactor (remote operation of course). It took the roof off the building!