Leasure battery in normal car

[Sp0_0k]

Hi. Trying to solve a fridge problem in our current car while we waiting for cali.
The goal is to have a 12v fridge on a gel battery which is charged during the ride and powers the fridge during stops.
Ideally want the whole system to charge from 240v as well.
So far trying to find a good gel battery charger for 12v and then build a switch so the battery is charged during drive and fridge runs directly from 12v car socket.
Anybody seen decent ready solutions for that?
Thanks.

 

[SlidePods]

You would ideally need to install a split charge relay between your engine battery and your gel battery to get a trickle charge from your car's alternator whilst driving. You can then fuse appropriately from your gel battery to run the desired 12v accessories.
With the 240v charging.... I would recommend you at least install a breaker between your charger and the external supply (if you plan to use unfamiliar supplys).

 

[Californiaman]

http://www.12voltplanet.co.uk/split-charging.html

 

[sidepod]

To run the fridge from a "12v car socket" you'd need to install an additional one as the "cigarette lighter" (if that's what you're refering to) is likely to be wired from the starter battery and as such may be isolated from the leisure battery via a split charge relay.

Regarding isolation/protection between mains input and sockets/charger you wil need a RCBO rated at 30mA max.

Getting nicely comlicated already isn't it

 

[TwentyOneThirtyFive]

Assuming this is a temporary solution, the simplest way would seem to be:

Charge leisure battery at home off of 240v.

During journey, plug a small (150w?) invertor into the ciggy lighter. Plug a battery charger (< 150w) into the invertor. Charge leisure battery during journey. Probably best to fashion some proper connections, not use crocodile clips.

Stop, unplug charger and invertor.

Enjoy cold beer until leisure battery is flat.

Plug invertor/charger in whenever you are driving about.

I've done the opposite (charged my cranking battery from the leisure battery via an invertor/charger) when my aux belt failed in Ireland. Kept us going until we found a garage.