# Leisure battery not charging when hooked up to mains ..



## nsr500rossi

Hi

This is my first post

i have recently picked up an old Renault auto sleeper (1985) and have been doing her up ..new floor, curtains, fixed propex heater, fixed boiler, fitted led lights etc etc, she is looking lovely and all is working well accept ...

When i hook up to the mains the battery does not seem to charge, the charge light is not coming on.

All lights etc work of 12v as they should, but the better is not charging

Any ideas as to why?

Just to add, if it helps .. i have a auto with relay fitted between the van and leisure battery.

Thanks

Mike


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## Firefox

The obvious thing is the mains charger fitted is not working. Also check leisure battery earth. A faulty earth can allow things like operation of lights but not be able to take higher charging currents.

If you have a multimeter, connect it across the top of the leisure battery, note the voltage. Now plug in the hook up... does the voltage change to about 13.5v or similar? Maybe the battery is charging but the charging light is blown. Check and replace any charging fuse if fitted.

If you don't have a multimeter then get one from Maplins or somewhere. They are essential to diagnose electrical faults.


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## nsr500rossi

Firefox said:


> The obvious thing is the mains charger fitted is not working. Also check leisure battery earth. A faulty earth can allow things like operation of lights but not be able to take higher charging currents.
> 
> If you have a multimeter, connect it across the top of the leisure battery, note the voltage. Now plug in the hook up... does the voltage change to about 13.5v or similar? Maybe the battery is charging but the charging light is blown. Check and replace any charging fuse if fitted.
> 
> If you don't have a multimeter then get one from Maplins or somewhere. They are essential to diagnose electrical faults.



Hi

thanks for the reply

I will test the voltage today (i have a meter)

You say it could be a problem with the battery earth, but the battery charges when the engine is running, so could it still be the battery earth

Thanks

Mike


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## Firefox

Probably not in that case, but still worth checking. Loose earths are the cause of many strange problems because they can take some currents but not others. A common example is the car lights work, but it just clicks when starting as the earth wont take the starter motor current. Check the voltage across the top of the battery, then check the voltage across the +ve and some bare metal point on the chassis. If these are different the earth is faulty, but check the solidity of fixing/corrosion of the earth cable at both ends anyway.

Your battery fully charged up should read about 12.7-12.8V across the top. Then start your engine and confirm the reading across the top terminals is about 13.5-14.5v to confirm the alternator is charging properly. Then switch off the engine and plug in your mains and see if you get a 13.5 - 14.5v reading. If you do, suspect the charging light. If you don't then suspect the 240v charger and/or fuses in the charging circuit. Someone who has an older Renault AS could probably tell you where to look


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## activecampers

Agree with all of above.

But also, if you are renevating, get familiar with all your wiring 

I'd disconnect the charger from the battery and check the voltage it is giving out closer to the charger. Also ensure teh 12v- from the charger (if earthed) is a good earth.  I have seen a (new) van where the charger worked, the batteries okay, but the connector block connecting the charger to teh batteries was disconnected.

There will be fuses between the charger and batterry, so check these are okay and the voltages are okay at both sides of the fuse. (I have seen a loose fuse before stopping it working)


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## nsr500rossi

Ok, so did some tests

Bearing in mind i have not driven the van for over a month, just started and ran in driveway, also the battery is only a few months old .

Voltage without engine running 11.8v

with engine running 12.4v and rising as engine runs

Now, with the mains plugged in.

The mains plugged in light comes on (red) on the zig unit, the charging light does not come on ..unless i flick one of the rcd's (one of the smaller ones, there are 2 small and one master) on and off, sometimes then the charging light will come on but only for 20 secs max, tested voltage when light on is 12.4v

Also, if i plus the mains in i can not light the propex heater when i have my lights on ..suggesting the mains is not supplying the power to the heater fan.

To add this is the same as when i am running from 12v, i have to turn the lights of to get enough power to start the heater, but this is because the battery is a little under charged.

Any ideas, why would flicking the rcd on and off make the charging light come on


Also tested the earth, red on battery, black on good bodywork earth, no change in voltage, so all fine there ..

Confussed??

Mike


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## Firefox

11.8v is a severely discharged battery. It should never get down to this level.

12.4v is not enough to charge the battery properly. What is the voltage at say 2500 revs? Suspect weak alternator if it isn't at least 13.5v. Also check voltage across top of engine battery  at 2500 revs to make sure proper voltage is getting through to leisure battery.

Again, 12.4 v from the 240v charger is not enough. This has to be at least 13.5v for effective charging. Bear in mind, battery fully charged is 12.8 volts so charging voltage has to be considerably greater to push the charge back in eg 13.5-14v

It's possible your battery may already have been damaged at these low voltage levels. Give it a good run off the engine or use an external battery charger overnight to see if you can get it up to 12.8v or thereabouts.


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## nsr500rossi

Just tested again after running van for 5 mins

12.15v engine not running

12.75 engine running

Panel light are: fully charged (green)
normal (yellow)
low recharge (red)

plus, mains on (red)
charging (red)

After running van for 5 mins lights go from yellow normal to green and yellow, fully charged and normal

when van is running lights just show green fully charged


Would the mains charger not kick in because the panel is showing the battery as normal?


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## nsr500rossi

Firefox said:


> 11.8v is a severely discharged battery. It should never get down to this level.
> 
> 12.4v is not enough to charge the battery properly. What is the voltage at say 2500 revs? Suspect weak alternator if it isn't at least 13.5v. Also check voltage across top of engine battery  at 2500 revs to make sure proper voltage is getting through to leisure battery.
> 
> Again, 12.4 v from the 240v charger is not enough. This has to be at least 13.5v for effective charging. Bear in mind, battery fully charged is 12.8 volts so charging voltage has to be considerably greater to push the charge back in eg 13.5-14v
> 
> It's possible your battery may already have been damaged at these low voltage levels. Give it a good run off the engine or use an external battery charger overnight to see if you can get it up to 12.8v or thereabouts.




Ok voltage on leisure battery when running with choke out is 12.84v

Same test on van battery is 14.4v

Mike


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## nsr500rossi

So power is not getting to the leisure battery, or not enough, either from mains or from van battery it is fine to the van battery at 14.4v, so alternator is ok?

Could it be something simple?

Also i have a car battery charger, a halfords job, says for 12v lead batteries, has normal and fast charge up to 1200cc, will this be ok to charge the leisure battery o normal, or will it damage it

Thanks

Mike


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## Firefox

The battery voltage will never get to fully charged with a 12.75 charging voltage. The lights may go to green, but I'd check them after half an hour when the battery has had time to rest.

Sorry to say it, but the whole system seems shot to me, if the readings from your multimeter are right. If you have another vehicle try calibrating the meter by checking the the voltage across a charged battery on that and then see what it changes to when the engine is running. Or try it on a friend's car if you don't have another vehicle. You should get about 12.8V at rest and 14.0v alternator running at reasonable revs if your multimeter is correct

The voltages on your van are all very very low, I don't think the battery is getting charged much at all by either the engine or your charger. It may work after a fashion but you'll get all kinds of strange faults if the voltage is that low. Those red, yellow and green LED can also be very misleading. They are quite crude and also the zig unit may be 26 years old if it is 1985 build. 

If your meter is working properly, I'd try giving the battery a good couple of hours charge on a drive to somewhere. Then see if you can get it to 12.8 V and it stays there after you let the battery rest for a couple of hours. Then see how long you can operate the lights and heater and other accessories before the leisure battery gives up. See if the performance is satisfactory for your needs. If not it would be time to think about replacing some components. At the moment, your alternator, 240V charger, and Zig unit all look suspect, if your multimeter is correct.


Edit - Just saw your other post. Yes your van battery is giving the correct voltage at 14.4V on the alternator so that seems OK, and multimeter seems OK. Charge your leisure battery off the other charger you have - it will be fine but give it overnight as the charger may only be for small batteries (1200 cc engine?) See if you can get the battery to 12.8 v and do the performance test above. Maybe it is the charging relay is faulty and not giving you the full alternator voltage)


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## Bigpeetee

Could be that there is a resistance between the vehicle battery and the leisure battery.

If the leisure battery is quite flat, it will try to draw quite a few amps, basic ohms law states that voltage = current X resistance, so the more current you try to draw, the greater the voltage drop or loss, eventually, the leisure batt voltage may rise as it gets a charge.

You could have resistance in:

a the positive feed to the batt
b the negative feed to the batt
c both a+b

With the engine running measure with the voltmeter between the two negatives, then the two positives. You might want to switch to a lower voltage range say 2v or 2000mV

To do this will mean that the meter leads will need extending, a length of household flex is useful, insulate where you make the joint.

You will find that possibly there is a greater voltage drop on the positive lead as it goes through a relay and a fuse. Try unplugging the relay and reseating it, same with the fuse, making sure there's no corrosion.

Of course, if the converter didnt use big enough wire, then at high current that alone can cause the voltage drop.

If you find that there is a voltage drop on the negative lead, there is usually a vehicle earth return. Measure between the leisure batt negative and a clean part of the body. Ideally there shouldn't be any voltage showing, if there is, remove the earth cable from the body attachment and clean, going back to bright metal. A smear of vaseline helps keep the connection.

I presume that the batt terminals are clean and have a smear of vaseline on the faces.

Try that and let us know.


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## nsr500rossi

Bigpeetee said:


> Could be that there is a resistance between the vehicle battery and the leisure battery.
> 
> If the leisure battery is quite flat, it will try to draw quite a few amps, basic ohms law states that voltage = current X resistance, so the more current you try to draw, the greater the voltage drop or loss, eventually, the leisure batt voltage may rise as it gets a charge.
> 
> You could have resistance in:
> 
> a the positive feed to the batt
> b the negative feed to the batt
> c both a+b
> 
> With the engine running measure with the voltmeter between the two negatives, then the two positives. You might want to switch to a lower voltage range say 2v or 2000mV
> 
> To do this will mean that the meter leads will need extending, a length of household flex is useful, insulate where you make the joint.
> 
> You will find that possibly there is a greater voltage drop on the positive lead as it goes through a relay and a fuse. Try unplugging the relay and reseating it, same with the fuse, making sure there's no corrosion.
> 
> Of course, if the converter didnt use big enough wire, then at high current that alone can cause the voltage drop.
> 
> If you find that there is a voltage drop on the negative lead, there is usually a vehicle earth return. Measure between the leisure batt negative and a clean part of the body. Ideally there shouldn't be any voltage showing, if there is, remove the earth cable from the body attachment and clean, going back to bright metal. A smear of vaseline helps keep the connection.
> 
> I presume that the batt terminals are clean and have a smear of vaseline on the faces.
> 
> Try that and let us know.



Ok thanks for your reply

Just tested with meter set to 20v still

Neg to neg reads 1.30v

Positive to positive reads 0.35

Leisure neg to body reads 1.30v

Battery has been on charge with halfords charger for 1-2 hours battery reads 12.4v

So what does all this mean

Many thanks

Mike


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## nsr500rossi

Anyone there ... ;-)


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## MartianTom

Wish I could help out, but I've got the same problem.  A brand new battery went flat on me after just a week of lots of miles, electrical hook-ups and minimal usage.  Still trying to figure it out.  The volt meter should show something when you're running the engine or on EHU.  If not, the on-board charger may be faulty, or you might have a fuse gone somewhere.  I think I'm just going to end up getting an auto electrician to look at it.

Good luck.

PS Here's my thread in case it contains any useful information

http://www.wildcamping.co.uk/forums/motorhome-problems/15026-leisure-battery-flattened-fridge.html


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## nsr500rossi

MartianTom said:


> Wish I could help out, but I've got the same problem.  A brand new battery went flat on me after just a week of lots of miles, electrical hook-ups and minimal usage.  Still trying to figure it out.  The volt meter should show something when you're running the engine or on EHU.  If not, the on-board charger may be faulty, or you might have a fuse gone somewhere.  I think I'm just going to end up getting an auto electrician to look at it.
> 
> Good luck.
> 
> PS Here's my thread in case it contains any useful information
> 
> http://www.wildcamping.co.uk/forums/motorhome-problems/15026-leisure-battery-flattened-fridge.html



Sorry to hear about your problems, it's all fun and games yeah!!

I have charged the battery overnight, it is now showing 13.8v, although i guess this will go down after disconnecting the charger for a couple of hours..

i have looked at the wiring and fuses under the bonnet, the fuses from the zig splitter and from the starter to leisure battery are both pretty corroded..

I am hoping this could be the problem, of to halfrauds in a mo to get replacement inline fuse holders and fuses, think i need a 30A from battery to battery and maybe 5A from zig relay to alternator, hope this is correct

Will let you know how i get on ..

Mike


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## Bigpeetee

Been to a gig last night with daughter singing so been away from PC.

Looking at the voltage drop on the neg lead looks like you've got earth issues.

Follow the negative lead to where it connects to the chassis, prob bolted to body.

Remove fixing, clean and re assemble.

Just check from the main engine batt to chassis, sometimes it goes via the engine, so that it starts well but there is a voltage loss for the rest of the equipment, lighting etc.

The positive loss is probably due the resistance of the feed cable/fuse etc not so much of an issue just yet.

You could always just run an extra wire from the neg to neg terminals to help. Try an old piece of mains flex just to try it out


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## nsr500rossi

Hi Pete

Well i cleaned the earth cable where it attaches to the engine (my leisure battery is under the bonnet next to the engine battery)

Also attached a spare earth cable between the neg terminals

Has not made any difference to the problem, i plug the mains hook up in and the battery charging light comes on for about 30 secs (sometimes less) then goes out

My battery has been off charge for 24 hours, when i did a volt reading it showed 12.9v, so i guess the battery is fine

When i start the engine and measure between the terminals it reads 14.25 volts so alternator charge is fine.

When i plug the mains in the voltage jumps up to 13.4volts, the mains then cuts out and the voltage starts to drop down again

Obviously 13.4volts is not enough

I have bought new connectors for the batteries and new fuse holders, i will fit them all today.

When i plug the mains inI can here a humming noise from under the fridge, behind a panel, guess that is the charger (i can not see it) humming noise stops when charge light goes out, i wonder if there is a problem with the charger ..

I will do some more resistance tests in a mo and post them for you

Cheers

Mike


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## nsr500rossi

Battery show 12.93v and is stable at that voltage now

Resistance tests

Engine running slightly fast idle choke on a bit

Meter set to 2000M

neg to neg with extra earth cable running between terminals 011

positive to positive   -112

Leisure earth to body 10

Engine neg terminal to body -001

Between terminal leisure battery 14.25v

Any ideas, could it be a zig switcher relay problem?

thanks again

mike


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## nsr500rossi

Update

I am going backwards .. ;-(

I have cleaned all the connectors on the zig relay, fitted new spade connectors to the wires that connect to the relay

Replaced the 2 inline fuses (they were corroded) with mini 25amp fuses (the square type with 2 prongs)

Cleaned the area on the body where the earth wire from the engine battery connects, this also has a wire from the zig relay and a wire from the coil ( think) these were all cleaned and vas aline applied

Replaced both battery terminal connectors on the engine starter battery, cut all wires going in (positive and negative included) so they are fresh and clean

Now the mains hook up does not come on at all, well it says mains connected but no charging light, it flashes on and off sometimes when i plug in the mains

Also now when the engine is running, i do not get the reading of 14.4vs as i did before, i now get 13.3v!!!!

if i run the spare earth from the engine battery to leisure battery earth it jumps up to 14.4v again

The resistance reading from leisure earth terminal to body is now 586 when on 2000 ion the meter, so resistance is a lot more now

I have removed and checked all connectors several times, all seems fine

What have i done wrong, am lost

Heeeelllllppppp

Mike

To add i even tried running the spare earth from the engine neg terminal to a place on the body, to check if i had a bad connection on there original neg to body cable ...this made no difference


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## Bigpeetee

Looks like there is still an issue with the earth lead on the leisure batt, I don't know how thick it is.

Obviously it's difficult without seeing it, but you are getting 0.6v drop at least. Why not just make a permanent connection between the two negative poles, a short length of suitable cable should do it.

I don't know your charger unit, but is it one that only operates when the battery voltage starts to drop?  It may be slightly intelligent and think, "well the battery is charged, it doesn't need me" so that when you first connect it to the mains it shows a charge, but recognises that the batt is full and switches off.

Try just running a load for a while until to leisure batt voltage drops, then try the charger.

Just switch everything 12v on, lights, TV etc.


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## nsr500rossi

Thanks Pete

Well the leisure battery does not have an earth on it, just a black thin wire from the negative terminal that goes into the van ..i guess to the zig panel and a red wire that also goes into the van, i also believe there is a red wire going to the positive terminal from the zig relay.

So a permanent earth wire between the terminals would be ok?

I will try your suggestion for running the battery down, although the van was made in 1986 so am not sure if the charger would be intelligent, if i remember rightly, when the battery was not fully charged the mains hook up still did not work, although i never had the neg to neg cable attached

I really appreciate all your help Pete, you are the only one with suggestions

Mike


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## Bigpeetee

No probs, but the leisure batt should have a substantial earth, connecting the two negs together is perfectly ok.


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## nsr500rossi

Cool

I wonder why i does not have an earth already, how was it supposed to work ...very strange!


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## nsr500rossi

Bigpeetee said:


> Looks like there is still an issue with the earth lead on the leisure batt, I don't know how thick it is.
> 
> Obviously it's difficult without seeing it, but you are getting 0.6v drop at least. Why not just make a permanent connection between the two negative poles, a short length of suitable cable should do it.
> 
> I don't know your charger unit, but is it one that only operates when the battery voltage starts to drop?  It may be slightly intelligent and think, "well the battery is charged, it doesn't need me" so that when you first connect it to the mains it shows a charge, but recognises that the batt is full and switches off.
> 
> Try just running a load for a while until to leisure batt voltage drops, then try the charger.
> 
> Just switch everything 12v on, lights, TV etc.



Hi Pete

Well, i have reconnected the neg to neg terminals, voltage up to 14.3v when engine on

I have tried leaving the lights heater etc on, voltage drops steadily, when down to 12.5v i turned the mains on, it comes on for a few seconds then goes of, when connected and on the voltage does not jump up to 14v like when the engine is on, it just slowly rises 

This does not seem right, surly when i am down to 12.5v with everything on i should get a charge from the mains

Maybe time for an auto electrician 

Mike


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