New leisure battery last autumn, charging via a Ctek MXS 5.0 . Always been fine but while on Isle of Wight, the Ctek refused to go past 1st green light which indicates trying to sort out a sulphate battery. On the basis that the bus is always plugged into the mains at home, I presumed that the short journeys/ long periods off mains while on Isle of Wight had drained the battery, so bought a simple charger from Argos to get some charge into battery so Ctek could cope. On hour round trip for a charger, when I got back to site, fridge was nice and cold....went out for day with friends, leaving battery on charge ( with Argos charger). Got home 6 hours later ... fridge not even cold. Checked Ctek on starter battery, works fine. Anyone any ideas, as hate throwing food away and hate buying a new battery every year even more!
I've had a CTEK fail to start charging if the battery is very flat, but it did recover and start charging after several attempts, on, off, on etc. Probably doesn't help you, however, coz it sounds like the battery isn't holding charge
Strange that fridge gets cold on run, but won't run off battery .... thought split charger sent power to leisure battery when running.....so fridge is surely fed from leisure battery running or not.
You're net minus it sounds. The charger can't cope with the draw from the fridge. You need at least a 7 to 10amp charger to keep an absorption fridge happy when on mains, and put back into the battery what else you've taken out by normal camping. IE lights, music, charging etc. The ctek, or any voltage sensing charger, needs to be able to see voltage at the battery terminal or it just won't work. You can kid them by either running the engine or connecting the SB in parallel and connecting the charger. Be aware though, the in rush current from the alternator can blow the split charge relay if the leisure battery is properly flat. (depending on the rating of the split relay) It's possible you are asking too much of a 5amp ctek if you are expecting it to keep a battery fully charged that is running an absorption fridge
As @theBusmonkey says, there's your problem, you need a bigger CTEK for camping, when you're running other appliances, or get a compressor fridge.
I think what I'd do is remove all the connections off the SB and the LB. Connect + to + and - to - with my jump leads, connect the charger to the LB and switch it on. Remove jump leads and let the charger do its thing. Eat what's in the fridge and let the charger just charge up the battery overnight. It'll need at least 15 hours if it's a 75amp battery being fed by a 5 amp charger! It may yet be goosed as lead acid batteries do not like being fully discharged. Remember to reconnect the SB lol.
Whoops, missed that, so it is, poor thing won't keep an absorption fridge going full time, will it? I use a 300watt CTEK to run mine, and all my other stuff, a bit over spec but in the 30+ degree C heat of France two summers ago, it was still getting quite warm.
I assume your absorption fridge usually runs okay off the 12v when you're not driving? Stupid question, I know, but I ask because the wiring for my 3 way absorption fridge (gas, 12v, 240v) is done to only work off the leisure battery whilst the ignition is on and the engine is running. Ergo, cold fridge at the end of the journey to a campsite, but won't stay cold unless I hook up to the mains directly, or fire up the gas. Hopefully your issue is easily sorted, and just requires a bigger ctek
I suffered the same thing for years. Old Westy fridge on over night and the leisure battery flat in the morning . That was with an old 12amp charger on all the time. Check out my thread on the new system I have now. That way you could keep the ctek but run the fridge off a totally separate 20amp power supply
Just got my head back straight, after a chill and a beer. Talking out of my a##e ...it's a compressor fridge .... so Ctek might by adequate? Rarely use anything else 12v other than the tap. Still can't understand why the battery didn't last a year, may try using my "spare" starter battery ....or is that a bad idea ?
A 5 amp charger will be close enough, I wouldn't have thought that it couldn't keep up What is the Halfords charger rated at? How about running an experiment? Charge the battery, test its voltage, then switch on both the fridge and the charger and then come back the next day and see what's what?
6w one, not got a multimeter with me ...got to take Argos charger back, left it charging this morning with needle on low battery, came back teatime to (apparently) charged battery, well according to gauge anyway....disconnected and needle stayed at fully charged.
