Connecting fridge directly to battery

[ditchcrawler]

I have a Waeco portable fridge/freezer which runs off mains when in marina & 12v when not.I have one 12v socket in my rear cabin & I usually run my plotter off this.I cannot run both at the same time(when fridge cuts in plotter goes off).
I intend to run a 12v socket (fused) with heavier gauge wire direct from my batteries as this is the shortest & easiest routeThe question is, as I have two 110amp batteries in parallel as my domestics(they are the same age & type) can I connect just to one domestic battery or do I need to connect to the neg of one & pos of other.I ask because one of the 110 batteries is easier to connect to than the other.Do the two domestics balance their capacity out i.e. act as one battery.Just to make it clear I have a separate Red Flash starter battery.

 

[Csail]

Well the marine lecky that did ours connected to just one of the bats.

 

[Anonymous]

If your batteries are actually in parallel - i.e. heavy leads connecting neg to neg and pos to pos, then you can wire your extra socket to wherever is convenient in the battery box. If you are running a fridge it is worth making sure that you have a way to monitor battery volts - fridges have a habit of over-discharging batteries and ideally you don't want to let your battery volts fall below 12V off load. Your two batteries connected in parallel will both be charged correctly if you have a modern charger provided one of them does not have a shorted cell pulling the volts down. Check your charger spec and every so often make sure that what is happening is what is supposed to happen - sometimes it depends on how the charger was set, often by switches or links inside the box.

 

[Salty John]

No problem, you can take both connections off the one battery.

 

[Slipstream 34]

If you are worried about draining your battery, try one of these:
http://cgi.ebay.co.uk/BATTERY-GUARD-PROT...1QQcmdZViewItem

 

[Malcb]

As far as I know the Waeco has a built in battery guard. You can set the switch to Starter or Leisure and it will stop taking from the battery if it falls below a pre-determined level. At least my 18litre Waeco does.

 

[Csail]

Excellent.....just bought one, always leaving the freezer on.

 

[jeremyshaw]

There's also the JW Marine Fridge Mate (jwmarine.co.uk) which seems to be a bit more sophisticated - though quite a bit more expensive too. Not tried either personally, though am thinking about it.

 

[ditchcrawler]

Thank you all for your advice.I will be connecting to one battery in the next few days.My Waeco box does have an automatic cut out at low voltage.I also have a 20amp Sterling mains charger & an alternator management system.Should keep the Chablis nicely cool.