Leisure battery charging problem

Hi all
I have a problem with my leisure battery charging on my 1999 Harmony.  I have done some trouble shooting tests but not sure if I have covered anything or missed something!

Problem was first noticed yesterday evening - running on 12v the internal lights only lit one tube and the spot lights didn't come on.
I thought this was strange as I had had the van on electric hook up all day sunday (all 12v stuff turned off) so only the battery charger and 240v light was on.   The green light for the charger on the panel was on, the charger on/off switch was on but orange light not working.

I have been out tonight with a multimeter and done some test, results are below:

1) The battery charger on off switch is working ok - the orange light wasn't working as the wire connecting it was loose - tightened screw and it is now lighting up along with the green light on the charge panel.

2) With all 12v turned off I tested the battery with a multimeter across the terminals and it read 10.2v

3) I turned on the engine and the voltage on the battery jumped to 13.4v - this to me proves that the alternator is charging the battery - I left it running for a bit and then retested with engine off and battery charge had jumped to 11.3 - which I think shows the battery is charging and keeping a charge as it remains at 11.3 after the next set of tests and putting lights on for a bit.

4) Turned off the engine, connected the 240v supply and turned on the battery charger - multimeter across terminals still read 11.3 - this I think shows that there is no charge coming from the battery charger as I would have thought it would jump up to 13v or there about.

5) Checked the fuses in the bonnet - there are actually two near the engine battery - not sure why there's two but there both 30a and both look okay

6) Checked the 30a and 15a fuse near leisure battery under drivers seat - both ok

7) Checked that the fridge works on 12v when engine is running - it does and orange 12v light on fridge lights up - when engine turned off the orange light on fridge goes off - which is how it should work

To me this looked like the battery charger wasn't working.   Found the charger in the bottom of the cupboard - it seems to be ok.
There is a green light light on the charger when its turned on.

It has 2 red wires, a black and a brown coming from it.   According to the wiring diagram from the back of the unit:

First red goes to the leisure battery via 30a fuse and a relay
Second red goes somewhere that i am not sure where but when disconnected all 12v goes out in van
Black it the negative
Brown is the green LED in the control panel.

Putting a multimeter across these gets the following:

First red and black - 11.3v (same as the battery voltage)
Second red and black - 13.4v

So thats all the testing i've done.
I am not sure what the problem is as I don't really know what the charger red wires are supposed to read.

I am not sure if the problem could be the 2nd battery relay under the drivers seat thats not working - can't really get to it to pull it out and even if I did not sure how to test it - does anyone know what the relay is so I can try and get a new one just incase - halfords or similar shop?

Does anyone know what the voltage output from the chargers first red wire should be - should this also have a 13.4v(ish) output to charge the battery?  To me, as it is reading 11.3v is the same as the battery it looks like its not working properly and I am just getting a back feed from the battery.

Any help appreciated.

Richard

(On a positive note I have also tested the heating, water heater, cooker and fridge on both gas and electric and all are working fine - at last something works properly!)

blimy talk about blinding with science.seriously i would check the fuses under the bonnet that looked ok.sometimes looks can be deceiving.one of mine looked ok untill properly checked.the fuses nearest the battery go quite often.good luck g.

If I put all the 12v lights, the 2 spots, the fridge and TV on they all work when on 240v hook up.  If the leisure battery is charge up by running the engine then they all work fine on the just the leisure battery - have been working in the van for a couple of hours each night last week without running the engine or hookup with just a couple of the lights and TV on, so I think the battery itself is ok.

Richard

They tested ok with a multimeter but will double check tomorrow and also try and work out why there are two 30a fuses - just looking at the manuals I got with the van and it says only one!  
Maybe there is a split charge thingy in there somewhere...although not sure how I can tell if there is or not...
Richard

The voltage shouldn’t jump up.  At [b]“normal”[/b] charge currents the terminal voltage should only rise very slightly initially and then go up very slowly as the battery charges up. If it jumped from 11.3V to 13V immediately it would be a sign of a duff battery - it simply can’t charge up that quickly.  The best way to check is to actually measure the charge current (or wait several hours before rechecking the terminal voltage).

First red and black - 11.3v (same as the battery voltage)
Second red and black - 13.4v [/quote][b]This bit is a guess[/b] ( you don't say which system is fitted), no doubt if anyone knows better they will chip in shortly.

It sounds as if you may have two outputs, one charging the battery and another supplying the van. That would mean the control unit was disconnecting the battery from the van and taking over the 12V supply while using a second output to charge the battery.  The charger voltage will be almost the same as the battery voltage. The fact that it is 11.3V is not a problem in itself but if it doesn’t rise slowly it indicates that the battery isn’t charging.

So what to do next.  

My advice would be to do another couple of measurements.  Firstly measure the current from the 11.3 volt output. If it’s several amps the battery is almost certainly being charged. If not disconnect the output and see if the voltage jumps to 14(ish) volts. If it goes to zero the charger is probably faulty.
One thing to bear in mind is that some designs of charger will not provide an output if no battery is present which complicates fault finding a bit. I doubt if this type of charger is fitted to your van.

Brod.

One other possible cause could be the relay, loose or dirty contacts.

How do I measure what amps are being used? I have a digital multimeter but the only way I know to use it is either to measure AC or DC voltage or make it beep for a continuous circuit!

The battery tonight still measures 11.3v so it's kept what charge it has - I can't test the output on the charger tongiht as its too dark to see!

I will try and test it tomorrow before it gets dark and I can't see - I might also go for a ride in the van and let the van charge the battery up and see if that will kick-start the charger when I get back.

Richard

Hi if you have a normal battery charger why not charge the battery and then see if the on board charger will maintain it

Hi. Don't have one although may need to get one - years of having a company car that just goes to the dealers when there is a problem means my vehicle maintenance tools are some what limited!

To get better access to the battery I think I need to take the drivers swivel seat out - is there a simple way to get it out or just a couple of bolts somewhere - does anyone know how to do this before I end up stripping it down too much!

thanks
R

Are both red wires fairly fat or is one much thinner than the other? Can you easily get to either end of the red wires? If one is thick (the one with the 30A fuse) and th eother is much thinner then it is likely that the thinner red wire is to let the van electrics know that you are on mains - ie it would feed a changeover relay. What make is the charger? - you can probably find full instructions somewhere on the web and others on this forum will have the same charger and may be able to help.

The charger is a Zig X7.  Both the red and black wire are the same size - the brown is quite thin but I think that just drives the bulb the lights green on the control panel.
I can't really trace the wires as they go under the floor and disappear - the charger is in a cupboard at the back of the van and the battery is under the drivers seat
Richard

The manual is available here
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Looking at the diagram it seems to me that Pins 1 and 2 on your ZIG are the 2 red wires. Pin 1 goes to the leisure battery via a fuse (30A for you as opposed to 25A in diagram).
Pin2 is fed from the alternator via the split charge relay (RM14? on the diagram).  That closes when the ignition is on and thus gives power to the fridge  (Pin 6 on 12S) and to pin 2 to charge the leisure battery. I presume that there is switching in the ZIG to connect 1 to 2 at appropriate times (appropriate to ZIG manufacturer that is!). The diagram is intended for caravan and towcar, hence the 12S socket.  You can assume that those conections are permanent and for Car battery read vehicle battery.
Aux on the control panel means that the van electrics are being powered by leisure battery, car by vehicle battery.  Mains comes into the ZIG which then directs 12V to either the leisure battery or the vehicle battery but, I suspect, not both.  The two fuses near the vehicle battery are one for alternator charging leisure battery (middle 25A on left of diagram) and th eother may be the fridge (15A) or the van electrics when powered by vehicle battery, bottom 25A on diagram).  If you play with the three fuses that you have found then you should be able to trace what wires do what, which will help in isolating the fault.  But there may not be a fault.  If the leisure battery was down to around 10V a 25A charge from the alternator would lift it quickly.  Just 3 or 4 amps from the mains charger would take MUCH longer to make a difference.
Just try leaving the mains charger on overnight and see what that does to leisure battery voltage as a first step.

Sorry this is rambling - I'm thinking on my feet and the edit was to let me look again at your first post.

Hi  



Personally I'd still prefer to go down the measurement route because it will quickly prove whether the charger is working.

However, to answer he previous question about measuring the current:

To measure voltage you connect the meter from positive to negative since the voltage is across the cables. To measure current you connect the meter in line with the cable since the current is flowing through the cable . The actual settings vary a bit from meter to meter.

First look at the range change switch, hopefully there will be a 10A (or similar) range.  Switch to it. Make sure the meter is switched to 10A DC (not AC).  

Then look at the sockets that the leads plug in to. The black lead will be in a socket marked  “common”.   Look for a socket marked “10A” or something  similar and move the [b]red[/b] lead to it.

Disconnect the positive (i.e. red) cable from the charger and connect the back meter lead to it. Then connect red meter lead to the charger output (the one you disconnected). The meter will read the current.

It goes without saying that from the safety point of view you need to make sure that there is no possibility of any cable shorting to earth during the process.

It's much simpler to do than to explain. Here is a video that might make it a bit clearer.
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A couple of warnings though.

I don’t know what type of meter you have but the cheaper meters usually have no form of protection against excess current on the high current range. If they are accidentally connected across the supply it’s usually “end of meter” - on the current ranges anyway  .  Move the red lead back to the voltage socket as soon s you’ve finished the current measurement.

For the same reason I wouldn’t recommend trying to measure the alternator charge current unless the battery is known to be reasonably well charged.  If the battery is flat the charge current will be well over 10A.

It’s very unlikely that the mains charger fitted to the van will supply over 10A but if you want to be absolutely sure you could connect a 10A  fuse before you connect the meter. Then wait for a [b]few minutes[/b]. If the fuse doesn’t blow the current isn’t significantly over 10A.

Brod.

[quote="RichardB"] To get better access to the battery I think I need to take the drivers swivel seat out - is there a simple way to get it out or just a couple of bolts somewhere - does anyone know how to do this before I end up stripping it down too much! [/quote]

Held in place with 4 countersunk Allen bolts.
Two in the front and two at the rear.
You will need to swivel the seat around to gain access to the rear ones, one at a time.

The seat will 'lift' off.
Get someone to help you as it is ****** heavy. (done my back in last time)

PB

It certainly looks like you are right and it has been incorrectly wired up.

The only uncertainty in the manual is what (in your numbering) terminal 6 does - it seems to be shown in their wiring diagram but not described. Using your numbering, terminal 1 is (as marked) the charging LED, terminal 2 the leisure battery -ve, terminal 3 the vehicle battery -ve, terminal 4 the vehicle battery +ve (via fuse) and terminal 5 the leisure battery +ve (via fuse).

Hopefully you will find that the existing wire on terminal 4 (your numbering) is the feed from the vehicle battery, and all that needs doing is moving the leisure +ve connection from terminal 6 to 5 (your numbering).

Hi  
   

-mojo- wrote:all that needs doing is moving the leisure +ve connection from terminal 6 to 5 (your numbering).

I’ve done a bit of investigating and I think that’s right  

Looking at the wiring diagram the X7 and X70 look very similar. My van is fitted with an X7 so I pulled it out this afternoon to confirm the wiring.

It is (using your convention from the left):

1 LED (thin wire to the control panel).
2 Earth (battery negative)
3 Earth (battery negative)
4 13.8V
5 13.8V
6 Aux (don’t know what it does but it’s not connected)

Pins 4 and 5 are connected together inside the unit.  There is only a single output with no separate battery charger so both the leisure battery and the output to the van are connected to this point.

I’m not sure what the orange light mentioned in the original post indicates so I still have a tiny nagging doubt about these conclusions. I’ve looked at the Zig control panel manual and as far as I can see there is no orange light mentioned there either.  
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Brod.

OK - a few more things to check IMHO. All terminals using your numbering.

First - unplug the mains

Disconnect the red battery lead from your terminal 6 (or remove the battery fuse which might be easier) and measure voltages between 2 or 3 and 4 or 5 or 6
What voltages do you get?

Then start the engine and again check the voltage across 2 or 3 and 4, 5 or 6.  What are they? 

I might expect around 13.8V on 6 based on your first post which gave 13.4V with the battery connected.  If 6 has a voltage around that level then the ZIG is putting alternator output onto terminal 6, even though the diagram does not say so, probably via an internal relay that would be energised from terminal 4 which I think should only have power when the ignition is on and, preferably, when the engine is running.

Then remove both the 30A fuses by the vehicle battery and check the voltages again with eengine and ignition off and with the Mains connected and with the ZIG switched on. You may have some switches on the ZIG control panel which will change charging between leisure and vehicle batteries which will affect those voltages.

If you can report back with all those voltages then we will have more to go on - reading the notes on the freewebs pages the the circuit diagrams that we have found on freewebs are just a subset of the units around which explains the discrepancies between the diagrams we have looked at and your unit.

I think that there may possibly be a couple of relays inside the ZIG which put power onto 6 from either the alternator or the mains transformer.  It may be that the relay for the mains side has failed. If that is the case then moving the red from 6 to 5 may be the wrong thing to do.

Have fun!

Brod posted while I was composing! Although 4 & 5 are connected that does not explain how your battery was being charged by the engine when on 6 - unless "Aux" is connected to 5 when 4 is energised.

brodco wrote:Hi  
   

-mojo- wrote:all that needs doing is moving the leisure +ve connection from terminal 6 to 5 (your numbering).

I’ve done a bit of investigating and I think that’s right  

Looking at the wiring diagram the X7 and X70 look very similar. My van is fitted with an X7 so I pulled it out this afternoon to confirm the wiring.

It is (using your convention from the left):

1 LED (thin wire to the control panel).
2 Earth (battery negative)
3 Earth (battery negative)
4 13.8V
5 13.8V
6 Aux (don’t know what it does but it’s not connected)

I’m not sure what the orange light mentioned in the original post indicates so I still have a tiny nagging doubt about these conclusions. I’ve 

Hi.  That seems to match how I have it setup at the moment and it looks to be ok but will do some more testing tomorrow.

How I have it, there are 4 wires that connect to the it - brown, black, and 2 reds

I have brown to my Pin 1 which is the LED
Black to my pin 2 with I am presuming is the earth
Red to pin 4 - when this is feeding the van 12v because all 12v goes off if I have this unplugged
Red to pin 5 - this is from the leisure battery as a test between this and the black shows the leisure battery voltage
Pin 6 has nothing connected to it (it did have the red now on pin 5) - it has no voltage on it when tested with pin 3

The orange light I refer to is on the mains switch under the cupboard for turning the charger on/off - it wasn't working but a wire had fallen out - its now fixed and lights orange when the mains for the charger is turned on

Richard

inspiredron
Disconnect the red battery lead from your terminal 6 (or remove the battery fuse which might be easier) and measure voltages between 2 or 3 and 4 or 5 or 6
What voltages do you get?

Between 3 and 4 and 3 and 5 I get 13.8v, between 3 and 6 it is 0.   With the red lead from 6 disconnected testing the wire with the black on 3 I get the same voltage as the battery

inspiredron
Then start the engine and again check the voltage across 2 or 3 and 4, 5 or 6.  What are they?  

I can't remember what it did when i tested this before but I will do it tomorrow morning

inspiredron
I might expect around 13.8V on 6 based on your first post which gave 13.4V with the battery connected.  If 6 has a voltage around that level then the ZIG is putting alternator output onto terminal 6, even though the diagram does not say so, probably via an internal relay that would be energised from terminal 4 which I think should only have power when the ignition is on and, preferably, when the engine is running.

I seem to thing that with the engine on 3 and 6 showed the same as the battery.

inspiredron
Brod posted while I was composing! Although 4 & 5 are connected that does not explain how your battery was being charged by the engine when on 6 - unless "Aux" is connected to 5 when 4 is energised.

The battery definitely shows 13.8v (or around that) when the engine is running and I disconnect all the red wires from the charger - on that basis could the battery be connected to the alternator via the relays under the drivers seat and the wire that I presume is going from the charger to the battery actually goes via a relay that switches between the alternator and charger?

Talk about confused.com…

richard

Sorry I have not come back sooner.
Remove all 3 fuses.
Turn on charger and set switch to vehicle battery.
Under bonnet:
Measure voltage across battery negative and the fuseholder terminal remote from the battery for each of the two fuseholders. One should show 13.8V and the other will probably be zero.
Turn switch to habitation battery - both voltages should be zero.
Turn off charger - both still zero
The fuseholder that showed 13.8V will be one of the reds at the Zig, the one that is attached to 4.

Replace both fuses and remove fuse by habitation battery. 
You may not be able to reach battery negative but you can use any bright metal bolt on the seat instead for the meter negative. 
Charger on and switch to habitation battery. Side of fuseholder remote from battery should be at 13.8V. 
Turn off charger and start engine - again the voltage across same points should be around 14V. That shows that habitaton battery is being chrged from alternator.
Replace fuse.
If you get my expected voltages and if the fridge light comes on with the engine then all should be OK.
I am still mystified by terminal 6. As I read previous posts you have no output on 6 from Zig but you do have around 14V when engine is running. Maybe you should check the voltages across 2 or 3 and 6 again with Zig on, and then with Zig off plus ignition on and then engine running. If all 3 measurements are zero then all is well with red to 5 - otherwise ???

Hi  

inspiredron wrote: Although 4 & 5 are connected that does not explain how your battery was being charged by the engine when on 6 - unless "Aux" is connected to 5 when 4 is energised.

I strongly suspect that it never did.  It’s pure conjecture I know but  I suspect that there may have been an X7 fitted originally, that has been replaced with an X70 at some time, and wired up wrongly in the process.  Since the alternator is charging the leisure battery normally you probably wouldn’t even notice that the EHU wasn’t doing so.

I’ve re-read both manuals and I think I’m beginning to see the light. I may be just me but I didn’t find the Zig manual very clear. OK they give you a suggested wiring diagram but nowhere do the actually tell you what the connections do.  I think pin 6 is an input.  

The  text in the X70 manual refers to an “Auto Power Diode Circuit”  as a connection to an alternate power system such as a solar  panel or wind generator.  Since we have accounted for the other five connections this would seem a likely function for pin 6 (still using the convention of counting from the left). That would also explain why the leisure battery was powering the van but not being charged by the Zig unit.
In the X7 manual the text refers to the extra connection as connected to a Schottky diode to be connected to the vehicle battery if a split charge relay is not used.

In either case it appears that connecting it to the leisure battery is incorrect.

I searched around the web for some AS wiring diagrams and one thing is for sure, there are several variations. From the original post It seems that both Richard’s and my van are wired more like this example from a  clubman (page 53).

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Brod.

Eureka! I was trying to think why 6 was marked aux and how the leisure battery could have powered the van from 6. Your explanation of solar panel and a diode explains it.