Question about charging 12v battery from transformer

[fitzy89]

Hi all

I'll start by explaining my situation. I have a caravan in the front yard which I am using as a work area for probably a couple of years. When I got it (from ebay, £50) it was in a bit of a state but had plenty of life in it yet. At the moment I am refitting the interior and redoing the electrics which had been ripped out by the previous owner. I have a consumer unit fitted in there and at the moment a couple of sockets and mains lights. Am I right in thinking as this is not the main consumer unit powering the house I can play with it till my hearts content without breaking any regulations?

There are some 12v bits and bobs remaining such as the odd lights here and there, so I would also like to keep a 12v system in there as well as mains (which will also be very useful for the work I will be using the caravan for). My question is, how to keep a 12v 65AH battery charged. I would prefer to have all the cabling all out of sight, also, the mains will be connected almost all the time so a normal car battery charger is out of the question as it would ruin the battery.

I have been looking at bell transformers which fit inside a consumer unit mainly due to their size and the fact that I won't need cables and crocodile clips trailing all over the place, something like this linked up to a charge controller such as this and a 65AH sealed lead acid battery. My current draw on the battery side will never be very high, probably never over 1A and not for long periods even then. I realise that bell transformers don't put out much current but I'm wondering if it will be enough to keep the battery topped up when needed and not have to worry about it cooking the battery?

Any advice would be appreciated, I guess for many of you that you don't deal with 12v items very often or even at all in some cases but as the battery was originally from an alarm system which some of you may have had experience with I hope someone can offer advice.

Thanks
Rob

 

[Deleted member 26818]

I would consider not using a battery at all, just a 12V transformer.

 

[telectrix]

what type of battery. you say a 65AH , but then you say it's from an alarm system. is it a car battery, or an alarm battery?

 

[pushrod]

You could try one of THESE or similar on the roof of the caravan

 

[Des 56]

If its a lead acid battery you have, 65 ampere hour,it would be larger than most common 51 ampere hour standard car batteries
With just a few items of the 12 volt system left, then it appears way over the capacity thats needed

They should charge at the 12 hour rate,so the charger should be capable of supplying the 6 amp current,so fairly large charger needed

Because of the need for a charging system, and maintenance of the battery,the storage etc,I would agree with others and say go down the transformer route, unless you wanted the 12 volt as a back up for the loss of mains supply as well as functional use

 

[Marvo]

I would also suggest a little PV set up on the roof of the caravan would be sufficient if you're not running much 12v stuff.