Battery charging

[GeorgenRuth]

Our Bongo is fitted with both a car battery and a leisure battery. It has a PMS3V/H Power Management system .Q. When the bongo is hooked up to an external electric supply and the pwer supply/charger switched on does it charge both batteries or just the leisure battery.. if so can it also charge the car battery ? thanks George

[dreamwarrioruk]

it depends how its wired up. if there is a split charge relay between the sb and lb then the idea is that the lb will not discharge the sb. so therefore the pms3v will only charge the lb

[Simon Jones]

I can't comment on the PM3 unit. but on a Zig CF8, you manually have to switch it from 'Touring' to 'On Site' to charge both batteries (as far as I can recall)

[GeorgenRuth]

Thanks folks...unfortunately I don't know if we have a split charge relay ... is there anyway I can find out ? cheers George

[dreamwarrioruk]

look under the bonnet and see if you have any wires that go between the two batteries for a start or if possible take a photo of it all so we can have a look

[GeorgenRuth]

That's very kind of you..will do.. Cheers George

[GeorgenRuth]

Dear Mike,Jo and Emma..had a look under bonnet..there is awire connecting the two batteries ..it runs from the leisure battery to a small black box at back of car battery and then wires from said box connect to terminals of car battery .. does this make sense .. it's all a mystery to me..Cheers George

[dreamwarrioruk]

it sounds like there is a split unit in there, any chance you could post a picture as that would make it clearer.
also from the black box is there any more wires. and what wires have you got connected to the lb +
if there is a split charge unit there should be some fuses on the wires going to the sb and lb, 50 amp size

sb = starter battery
lb = leisure battery

[GeorgenRuth]

Thanks again... yes there are fuses to at least one wire of both batteries..not sure about other wires there certainly are a few !! I' ll try and take a picture tomorrow..it's a bit cold and wet here at moment . regards George

[dreamwarrioruk]

i not too clued up on the unit, think ill need to read up on the power unit.
im gonna have to play with the panel i have in the caravan to see if it charges up the lb on the bongo when plugged into the mains.
there is a 3 way switch on the unit you have on the power unit car/off/van this will in a caravan select which battery you use but not sure how it gets wired in a bongo, have they taken a feed from the sb (car) and from lb (van) if so will it charge up both depending which way you have the switch.
hopefully geoff might pick up on this thread and put some input in as well.
if its wired only to the lb and there is a split charge relay in from the sb then you shouldnt be able to charge the sb as the relay will click off when the engine is stopped preventing anything from draining both the lb and then the sb.
hope im not getting you confused.

[madmile]

The PMS unit if wired according to the instructions (BIG IF, going on the mess someone showed me earlier this week ) anyway......
As Mike says, the CAR/OFF/VAN selector switches the battery from which the unit takes its power. As there are no other wiring configurations possible then the charger will charge either the van(leisure) battery, or car (main) battery so long as the charger is switched on and hookup provided.

Just as an aside, although not possible via the PMS unit alone, you can charge both batteries at once if you have a voltage sensing split charge relay.
If you chose 'car' battery then the relay switches at say 13.3v and splits the charge......however if the battery is quite low then its possible the relay will click in and out for a while as the low charge of the leisure battery brings the main battery down as they connect and so it falls below the switching voltage of the relay and then swiches off. I use this to keep a vehicle topped up if in storage for a while.

[dreamwarrioruk]

cheers ed
ive not had much to do with these units

[GeorgenRuth]

Thanks for all your helpful advice..it does seem quite complicated to my non-technical mind..good news is that having started Bongo with a spare battery and jump leads and taken it for a run all seems well and SB now charged..however just to see if it helps clarify the matter I have taken photos of said batteries as was suggested in an attempt to show you the wireing..my prowess as a photographer not much better than my lack f prowess as a Bongo technition but if I can attach the images and if they mean anything to you happy to receive comments..by the way if it is relevant I found a label stuck under the bonnet which states that batteries are wired in parallel ? regards George.. oops not sure how to attach images ..never mind maybe I'll try again later..thanks again for your advice

[mister munkey]

oops not sure how to attach images ..never mind maybe I'll try again later..thanks again for your advice

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[Aethelric]

If the black box you mentioned is a voltage sensing relay, then you may be able to charge both batteries at once.
The relay is designed to disconnect the main battery from the leisure battery when the voltage drops below around 12.4V. This happens when the batteries go "off charge.
If the charger is charging the leisure battery, and you momentarily start the engine, this should close the relay which will than stay closed when you switch off the engine as long the charger can keep the voltage above 12.4.

But you may not have a voltage sensing relay.