I am in the UK and have a 1994/5 southwind 33 a class petrol
I have been having problems getting the generator going think it may be a faulty earth lead as I can start it directly if I connect a slave battery direct to the generator and a separate fuel supply (main tank low) - starter a bit suspect though
Anyway, the batteries - engine starts ok but the leisure/coach batteries seem to be bad
I thought I would change all three as a precaution
Only one of the batteries has a label on it, and that is an 85amp leisure - the other two have nothing on them
As I look from the front, there are two lower batteries and one higher up on the left
The left one of the lower two is marked as a leisure battery
After removing the lower two, I assumed the higher left one was for the engine and left that connected but there is now no power to the ignition so I assume one of the lower ones is the engine battery
I would like to find out which one is the engine, what amp/cranking power it should be, and which ones are the leisure/house batteries and what amps they should be
The upper left battery in my 97 Bounder is the engine starting battery. With a 460 cubic inch engine, they recommend 1.5 cold cranking amps per cubic inch, or about 700 CCA rating.
I don't know how they rate batteries over there.
My two coach batteries are both 6 volts, with 3 battery caps per battery.
I don't know why your engine battery might have suddenly lost voltage. If you have a voltmeter, you can check it out.
We use 6 volt golf cart batteries to get the most amp hours of battery storage in the coach batteries, however 12 volt group 27 deep cycle batteries will work fine, as long as you can add water to the batteries as it gets used up while being recharged. Only add distilled water to the batteries.
It sounds like someone installed group 24 batteries where the factory 6 volt deep cell batteries where located. Group 24 is rated at about 85 amp hours storage capacity, while group 27 is about 100 amp hours. The golf cart batteries are rated at 220 amp hours, and you need the pair to get 12 volts at 220 amp hours.
You should test the engine battery to see it's voltage. It should be about 12.5 - 12.8 VDC.
Also my motorhome uses about 1.5 amp per hour to run the carbon monoxide and propane leak detectors, along with the refrigerator. So the RV really needs to be plugged in all the time, or the batteries disconnected from the coach (you should have a switch to disconnect the batteries by the door) so they don't run down the batteries and short out the cells.
The coach batteries are tied together, so if you look at the wiring, you can tell what pair are tied together, and what battery is separate.
The 6 volt batteries have an added bonus, only 6 cells to add water to, instead of 6 cells per battery.