Without getting too technical let’s take our setup of batteries in the caravan which is:

 3 x 12 volt AGM Deep cycle batteries. Each battery is 120ah (amp hour).

 The key to a battery is the ah reading. Ah is short for Amp hours. So for simplicity reasons, a 100ah battery means you can use 1 amp of electricity from that battery for 100 hours before the battery is totally flat. Connecting batteries in series doubles the voltage but keeps the amp hours the same. Connecting batteries in parallel maintains the voltage and increases the amp hours. Refer to google if you want to know more but in general for caravans you’ll be connecting in parallel.

Caravan’s use AGM deep cycle batteries (or better like the recent  Lithium 12 volt battery). They do not use the  standard lead acid starter battery that you use in your car. There’s a reason for this that I won’t explain here but for now just be aware that there is a difference.

​Connecting batteries



Having 3 x 120ah batteries connected in parallel gives us a total of 360ah of current we could use. however, a deep cycle battery does NOT like to go less than %50 charge or else the life expectancy of the battery drops dramatically. There’s a chemical reason for that which I won’t go into either  but feel free to read the battery university website if your curious. Therefore our 360ah battery system is effectively 180ah "useable" amps.  Which means in one day if we used 180amps of electricity, our batteries would be %50 flat. That’s as low as we would want them to ever be, which equals 7.5amps per hour usage.



Like everything its up to the individual to decide what's right for your needs. To help guide you in your decision try entering different battery AH ratings  in the below excel spreadsheet and see what results you get.
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