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Quote: Originally posted by Grampian91 on 21/6/2017

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I would want a minimum or 2 decent brand 110Ah batteries to run a load that big. A single battery may not like it.

Leisure batteries are designed for small loads and to be kept topped up.

Your going to be draining and charging above the average usage level. You may need to topup the electrolyte quite often. Or risk buckling the plates in the battery.

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Quote: Originally posted by fleck2 on 21/6/2017

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Your 240g per day fridge gas usage is the same as mine.
Have you got refillable gas bottles? I calculated our 3 way fridge would use about £9 worth of gas a month and the fridges work better/colder on gas.

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Quote: Originally posted by insiorc on 22/6/2017

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I've overlooked a few things with getting focused on the fridge loads and changeover etc.
I appreciate the prompts.

On further digging on the Numax CXV35MF I see the 120Ah is calculated by a 6A load over 20 hours. While a 10A load isn't likely to cause any harm whatsoever, it will reduce the battery capacity to less than 120Ah.

Also the battery charge rate, which with a 120Ah battery and aiming for ideal max of 10% then the 150W panel at peak will deliver 12.5A - close enough to 10%, and is why I chose the original 150W size. But this reminds me that if fitting another 150W panel in parallel then it'd be best with a 2nd battery in parallel (series connected panels would be better for longer charging hours, especially where I live with the longer daylight but the CTek D250S cannot take the increased voltage).

My initial reasons for not wanting to parallel the batteries was thinking if the (mistaken) RM7271 fridge could be converted to AES then it'd only be a few hours through the night running on gas, especially if the 12V is thermostatically switched. This would leave my existing system independent. But I now know I have a manual changeover RM6291.
Also battery cable sizes, although possible space ways it's not ideal to fit the 2 batteries beside each other as it's to the front of the axles therefore increased noseweight, so I'd hoped to fit a 2nd in a locker behind the axles on the opposite side. Still possible but much longer cables so sizes go up to overcome Volt metre losses. Also cross connecting the caravan load cables adds cable length.

As I'm sure anyone reading this already knows, the costs for gained benefit is looking less attractive. My dream of free chilling for beers is starting to look less likely
But I'm a stubborn and don't like to give up too easily.

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