I disagree. The charger just needs to provide as much in any given period, say 24 hours, as you will draw from it in the same period. Chances are your peak draw will come in the evening, with nothing overnight and next to nothing during the day, but if your charger is left switched on all the time it doesn't need to match the peak draw - that's what the battery is for. So the question should be, is 5A times 24 hours equal to the number of amp-hours I use in a day? Most people with a solar setup don't use hook-ups at all, yet those typically only supply a few amps for a third to a half of the 24 hour cycle. A big charger is useful for the odd occasion when you need to get a lot of amps into a flat leisure battery quickly, but how often does that happen? My 90A alternator is perhaps the biggest charger I have for that situation.California Dreamin wrote:Plus, you seem to be missing the point, which is that the leisure charger output needs to be higher than the 'possible' discharge. ie: more going in than being taken out, otherwise you are ultimately going to be running directly from the charger, which is not a good thing to happen.
At the risk of sounding like a cheerleader for this CTEK fan club, note that some of the CTEK units - the MXS7 and MXS10 I think - have a 'supply' mode which does just this. Mine has it, and it seemed like a good idea at the time I bought it (allowing the 12V electrics to work even without a leisure battery installed), but I've never used it - if the hook-up is available, then why not let it look after the leisure battery at the same time? I take your point about a big supply allowing the use of a smaller charger though.CovKid wrote:Assuming that (inverters aside) 240v supply needed to even run the CTEK, Numax etc, another solution is to fit an additional dedicated 240v to 12v supply which you can switch over to.
). I too am a retired electronics engineer and sadly I am well over 50 