12v electrics - operation and charging the leisure battery

[HW182]

Hi all,

Having recently picked up a T25 we're struggling a little with the 12v Electrics and charging the battery from the mains hook up.



we have the above control panel, if we select the "battery selector" to van, the 12v system doesnt work - am i right in assuming by putting the switch in this posision it should draw power from the leisure battery?

If we select "car" then the 12v system works, am i right in guessing this is drawing the power from the T25 main battery?

Similarly, we've plugged in the main hook up, switched the charger supply to on and the battery selector to Van - but it doesnt appear to have charged the battery - in the car position, the battery indicator comes on and shows the condition of that...

Any help greatly appreciated - if any of you have instructions etc and are happy to share that would be amazing - unfortunately when we picked up the camper all of this was lacking.

Thanks.

[bigherb]

Have you got a leisure battery fitted? Usually under the left front seat.

[937carrera]

That's a pretty decent PMS system you have fitted - same as I have in my truck.

I never touch that switch, pretty sure it is set to van permanently for me, unless I want to make the whole system dead. As Bigherb says first thing is to discover where the leisure battery actually is and make sure it is connected / servicable.

Manual for you

http://www.olearymotorhomes.co.uk/ekmps ... ctions.pdf

[HW182]

Hi both, there's a leisure battery fitted behind the drivers seat (the main vehicle battery is in the engine bay) and it *looks* new(ish). Next thing to test would be the battery itself by the sounds of it, and to test if it's been wired to the "car" switch...

Thanks for the link to the manual too - hugely appreciated.

[937carrera]

The car and van never made sense to me because I'm not dragging a shed behind either.

Car = starter battery

Van = leisure battery

Try this:

PMS off check voltage in leisure battery with a meter. Switch to van, how many lights & what colour on the battery indicator. Plug 240 in, check the voltage again.

You should see, 12.6v, 5 bars up to green, about 14v

[Mocki]

The car and van never made sense to me because I'm not dragging a shed behind either.

Car = starter battery

Van = leisure battery

Try this:

PMS off check voltage in leisure battery with a meter. Switch to van, how many lights & what colour on the battery indicator. Plug 240 in, check the voltage again.

You should see, 12.6v, 5 bars up to green, about 14v

its "car" and "van" because its a carAvan control box, not a camper one... most are not camper ones....

[bigherb]

Next thing to test would be the battery itself by the sounds of it, and to test if it's been wired to the "car" switch...

There should also be a main fuse for the leisure battery located near to the leisure battery.

Put the van year and engine in your signature so everybody knows which type of vehicle you have, stops us having to guess where your batteries are, Diesels are in different places to petrol engines, and a lot of things on these vans are year specific.

[HW182]

Thanks all, signature updated to save any confusion.

A bit of an update, we had the leisure battery on charge all day yesterday and tested it in the "van" position. It began showing 11.5v and this steadily decreased. In comparison the engine battery was showing 12.5v and remained constant.

It seems the leisure battery is not working as it should. We left it switched to "van" with the lights on for 3 hours in an attempt to draing hte battery completely flat (the idea being to drain it fully then re-charge it to see if the battery is faulty). After 3 hours it was showing only 5v on the leisure battery... i'm guessing this is not great considering we only left the lights on!

Conclusion, i'll fully drain and recharge the battery to see what voltage it puts out once fully charged from flat but am guessing its past its best so a new one may be fitted.

[937carrera]

Draining a lead acid battery is what kills them so that's a bad idea.

11.5v is no good for a leisure battery on charge so I would say that the PMS system is not charging. What happens if you move the switch to car and measure voltage at the leisure battery ? ....... maybe it's wired incorrectly ?

Do you have another way to charge your leisure battery, if no battery charger then jump leads from a running vehicle will work.

[LeeME3]

Frankly you're starting to damage a battery below 12v (ish - opinions / experience / manufacturers vary, but basically by 12v it is down to 50% capacity) so if it got down to 5v it is highly likely a dead 'un. I suspect it has been dead for a while so likely not your fault. Before putting a new one in you need to find out why it is not charging on hook up and also if there is something drawing on it the whole time. A lot of vans have (entirely sensibly) been wired so as things like the stereo / 12v sockets take from leisure battery not starter but if done badly (or your stereo has a high residual draw for example) this could be killing the battery over time.

Also, do you know if you have a split charge relay system? i.e. does the leisure battery get charged by the vehicle alternator when the engine is running? Easy way to tell...measure voltage across the battery with the engine off. Start the engine. Wait a few minutes for the split charge system to top up the starter battery first and then it should switch over to the leisure battery whereupon you'll see a voltage jump at that leisure battery.

You may find the following chart helpful, apologies if I'm teaching you to suck eggs but a lot of folk don't realize that a 12v battery showing 12v is only 50% full!!! It is a little counter intuitive...!