My little boat is a 30 footer. She has no inverter/hook-up to mains, and I would like to toddle off soon and do some exploring She has.a new starter battery, and a bank of 3 leisure batteries which have been left for the best part of year, and I am about to accept that they have had it, (have topped up cells, put bataid tabs in - yes, have been told not to bother). Batteries charge when engine running, and provide some power for a short time afterwards, but as predicted, then fail. Have had on slow charge and they read about 10.1 v after boat has been left for a couple of days (it was 4!).
Someone said they wondered if I needed three batteries for such a small boat, so my question is - how do you calculate how many batteries you need, and of what capacity please?
The power is needed for the following:-
Lights
Computer
Water pump
Charging mobile phone
Hairdryer (not daily)
I have a 12v TV on boat - not currently working - but would liike to include it in my list of power needs for the future.
Any advice/guidance much appreciated.