My van, a 2001 swift suntor 590 RS is fitted with a 85ah leisure battery. I intend to add a further battery of the same make and ah. (my existing battery is new). Can anyone offer advice on connecting them in tandem, also offer advice as to whether the alternator and charger on hook up will be able to cope with the extra charging demand.
the alternator will not give you good service you may have a 125/50 amp hour alternator fitted now but then you want it to give you another 85amp hour charge that,s a lot to ask .I think you would be better leaving it as it is.
------------- you may be frustrated now but infront of me there is a big incline . yeh it may be slow but it is in front
We had this query recently, if I remember right it got very complicated and the result was that he decided to charge the spare battery up at home and swap it over if he ever needed it.
I think we disagreed about wether the batteries would both charge up together , or discharge together.
The arrangement of two leisure batteries in parallel is very common on narrowboats. All also have a separate starter battery for the engine which is isolated from the leisure batteries. For further info try a boatyard or google it. A split charging relay works between the leisure and starter batteries. But, if I remember correctly, the two leisure batteries were simply connected in parallel. However, two batteries in parallel is never as much capacity as twice one battery, due to losses and differences. Two might only be 1 1/2 times one on its own. What about the extra weight? The suggestion of charging one up at home and then simply swapping over might be the best one as it involves the least loss of capacity. If you are on hook up why do you need another battery? A charged one should last for a few days. Other threads tell of folks who regularly go away for weekends without hook up and manage. Hope you find an answer that suits you.
Thanks to everyone for their contributions, I have taken it all on board and decided on a comprimise. I have managed to buy a 110ah battery which fits into the space nicely. I think that this will give me a little extra capacity without complications. Cheers.
I always favour keeping a spare fully charged battery this way if you get taken by surprise with a flat battery you can swap them. If you have them both in parallel and you run out of power, it might have taken longer, but you have two flat batteries and no backup.