Help needed!! Electrical system problem

[Rocky_7]

Hi All,

Me and my friend are currently parked outside a train station in Bologna in Italy abusing their wifi!
We are having a major problem with our van battery, in that it seems to keep discharging. I am going to take photos or maybe even a video so you guys can see the system.
It appears that both our van battery and leisure battery are working in combination but me and my friend are complete novices. We literally bought the van and set off haha.

Brief description of the problem:

We drive for say 100km and park up for the night. Use the interior lights for say 2 hours max. Get up in the morning and the van needs a jump start because the battery has drained.

Things we have tested:

We bought a battery tester from a store over here. After every drive the van battery reads 70%. The checker has an alternator checker on it too and this reads that everything is ok.
We removed the link up wires from the leisure battery and tested that, it appeared to have no charge whatsoever.
With the leisure battery out of the loop, we tested everything inside and it all still worked??
We have a cable running off the main battery that looks like it goes into the main fuse box, we took this off and everything still worked.
We have another cable which appears to go to some sort of relay near the leisure battery, when we took this off, nothing worked.
If we leave this cable on, regardless of whether we use anything in the van (interior lights etc) it still seems to discharge the battery??

As I say, we are completely clueless when it comes to all this stuff, so any help would be massively appreciated. I will try and get a video or pictures up of the batteries etc.

[walt1984]

It sounds like a couple of problems. The relay if wired correctly should put power to the leisure battery from the main battery when the engine is running. But if its not switching and letting power go to the leisure battery and the leisure batt is knackered that could be your problem.
If u put on what van, is the set up factory fitted or DIY and possibly photos people on here will be able to help u.

[walt1984]

Another thought. Do u have a fridge ?

[duvet]

instead of taking off wires .. take out fuses

[Rocky_7]

Thanks for the replies guys.. We wouldn't have a clue what we were doing with regards to removing fuses.. as I say, clueless.

We do have a fridge and had been running it off 12v (spairingly and mainly when driving). We quickly realised this was draining power massively.
We believe the leisure battery is knackered and old, so that could be at least one issue.

The van is a Transit 190 LWB 1991 H reg, I think its a 2.4DI? Its supposed to have been professionally converted but the wiring on the engine certainly doesn't look professional!! Maybe someones added some stuff?

Pictures: (we were trying to test stuff hence a couple of the wires are disconnected in the pics)

[walt1984]

Looks like a rip it out and start again. Where do the wire go when they are in the van ? Do they just go straight to lights etc or a panel with switches on ?

[ake]

Hi All,

Me and my friend are currently parked outside a train station in Bologna in Italy abusing their wifi!
We are having a major problem with our van battery, in that it seems to keep discharging. I am going to take photos or maybe even a video so you guys can see the system.
It appears that both our van battery and leisure battery are working in combination but me and my friend are complete novices. We literally bought the van and set off haha.

Brief description of the problem:

We drive for say 100km and park up for the night. Use the interior lights for say 2 hours max. Get up in the morning and the van needs a jump start because the battery has drained.

Things we have tested:

We bought a battery tester from a store over here. After every drive the van battery reads 70%. The checker has an alternator checker on it too and this reads that everything is ok.
We removed the link up wires from the leisure battery and tested that, it appeared to have no charge whatsoever.
With the leisure battery out of the loop, we tested everything inside and it all still worked??
We have a cable running off the main battery that looks like it goes into the main fuse box, we took this off and everything still worked.
We have another cable which appears to go to some sort of relay near the leisure battery, when we took this off, nothing worked.
If we leave this cable on, regardless of whether we use anything in the van (interior lights etc) it still seems to discharge the battery??

As I say, we are completely clueless when it comes to all this stuff, so any help would be massively appreciated. I will try and get a video or pictures up of the batteries etc.

Battery should read more than 70% after a decent drive.

[Kedishen]

So lets help you sort it out. Sorry there are soo many words.

First of all, if you don't have a multimeter, get one and if you are not familiar with using it, read this: http://www.wikihow.com/Use-a-Multimeter. Only section 3 & 4 apply, measuring voltage and amperes. Also remember 12v circuits are DC, not AC. Get a multimeter with a digital display, they are easier to read.

Secondly, you engine battery looks fairly new. There will be a date stamp on it somewhere. Some may also be marked when they were fitted. Heres a link to decipher date stamp: http://www.batteries-faq.com/activekb/q ... stionid=53

thirdly, your leisure battery looks quite old. However, it is not maintenance free like your engine battery and can easily be topped off with distilled water.
- Remove the 6 big plastic screws on top (a 50p works well) and sign a torch in.
- The metal plates in bottom should only just be covered.
- If you see bare metal, top up with DISTILLED WATER until the plates are JUST covered.
Ideally you would then charge the battery with a 3 stage pulse charger...


--------

The biggest question i have is:

With the leisure battery completely disconnected, and the wire to the box behind the leisure battery disconnected (so that nothing works inside van)... does the engine battery still drain?

If yes, when you are looking at voltage on engine battery, does turning the fridger 12v on and off change the voltage?
I am guessing it will since you suggested you have been using it without engine running.

Normally it would have its own relay to isolate it from both batteries.. When I got my van it didn't have a 2nd relay, just went straight to the leisure battery. I just added an old 30amp 4 pin car relay (normally open).

Take a better photo of the relay behind engine battery and the box behind leisure battery.


---------

Heres a run through of things you may want to do to find out what is going on with the wiring.

In the pics, it looks like there is a split charge relay (SCR) behind the engine battery (with the red cable on it going to leisure battery). This will keep the batteries isolated from each other when the engine is not running. When it is on, it either uses another cable to the alternator or does something electronic to sense an increase of voltage at the engine battery and allows charging current through the cable to leisure battery.

You SCR looks like it has a dial on the front to control at which voltage it will allow current to flow. As such, I will presume it is a electronic voltage sensing relay and not a mechanical switching relay.

You will need to do a bit of voltage testing to find out what is going on

Before you start, I would expect you to find and disconnect any cables connecting the ENGINE battery to circuits inside the van for lights etc... unless it has a zig type panel which has a switch to select which battery to use... Even if there is, still disconnect it. Will help with diagnosis

You will want to establish the following:

Are the batteries connected to each other and when?

1: With the engine off
- test the voltage of each battery. Is the voltage same?
- now switch on a few lights in the van, retest voltage on both batteries.. are they the same?

IF NOT THE SAME
- The batteries are isolated. This is good. Move to step 2.

IF THEY ARE THE SAME
- the is SCR set too low and you need to turn it up to at least 13.3v on the dial.
- or it is not connected at all and there is a wire running directly between the two batteries... somehow. Will most likely be a THICK wire or it would have melted by now (because of engine starting). Ideally this wire will be removed.

2: Are both batteries being charged from alternator?

- Run engine and give it a little rev to get the red dash light out.
- Test each battery, both should be at 13v+...
- are they both over 13v with engine running?

IF NO
- Your SCR is not working or is not connected somehow. (check fuses in any inline holders between engine battery - SCR - leisure battery)

IF YES
- This sounds good but lets not jump the gun.

3: Is the SCR working correctly?

With engine running:
- Disconnect the red wire at the SCR that runs from the leisure battery. (test leisure battery, voltage should have dropped)
- Now test the voltage at the SCR (on empty connection) with your negative going to exposed metal or negative terminal of engine battery.
- Are you getting 13v+?

IF YES
- All is well so far

IF NOT
- try testing the terminal on the other side, maybe the wire from engine battery at fault (or the fuse has blown if there is an inline holder)

4: Is anything drawing a load from batteries when everything is turned off?
(Since we know the batteries are isolated, they cannot be drawing power from eachother. Also, as have already found and disconnected any wires running to the camper electrics, we know the engine battery should be being under load).

- pull fuses in main fuse box for radio and dash clock.
- Disconnect the negative terminal of ENGINE BATTERY and test for amps between negative cable and terminal. You can do this at any point in the circuit if you want to.

IF THERE ARE AMPS

- Double check none of the van electrics are running.. heaters, headlights, radios, OPEN DOOR LIGHTS etc. If still drawing, looks like your van electrics are faulty

- Now do same for LEISURE BATTERY

IF THERE ARE AMPS
- pull fuses in the back to individual equipment and test for amps across fuse connections.
- If you can't find any leaks, may be a chafed wire somewhere, but that would likely blow fuses when equipment is running.

IF THERE ARE NO AMPS
- This indicates that one of your batteries is knackered since you were having to jumpstart van in morning. If leisure batt is knackered, it would have been draining the engine battery continuously... or visa versa as soon power was taken from it. Dead cells are annoying.

5: Are either of the batteries knackered?

(AFTER ESTABLISHING YOUR SCR IS WORKING AND BOTH BATTERIES ARE BEING CHARGED WITH ENGINE RUNNING AND NOTHING IS DRAWING LOAD)
- Drive with both batteries connected so they are charged.
- after stopping for the day, AND BEFORE USING ANYYTHIGN INSIDE VAN - disconnect the ENGINE battery (at the battery terminals themselves) .
- Read the voltage at each batteries after disconnecting engine battery (give them a few minutes to stablise after disconnecting). I would expect the following:

Engine Battery (good condition): 12.7-12.9v FULLY charged.
Leisure Battery (good condition): 12.7-13.1v FULLY charged.

These are based on voltages I get from my batteries.

6: Load test (Leisure battery)

(Don't run your fridge off 12v without the engine running... ever... unless you have at least 7amps of current running into the batteries at the same time (from solar or wind energy perhaps). My 3 way fridge is electrolux RM4200 and draws 6.5amps on 12v).

- Use your lights and everything as you would normally.
1 single flourecesent tube light will use between 0.5-0.9amp.
An average fullsize laptop will use 2-4amps (on a 12v power supply, more if you use an AC inverter)

a 100ah leisure battery will run for 3-4 hours with a 4amp load before running beneath 12.1v (UNDER LOAD)
After turning off the load, it would normally stablise at around 12.3-12.5v depending on how deep into 12.1v you ran it.

a 100ah leisure batt will run for at least 20-24 hours with a 1amp load before hitting 12.1 (UNDER LOAD)

Keep this in mind. Its best not to let your battery run down below 12.3v without load.. ideally never below 12.5v (but this is unrealistic if you want to use laptops and such)

- If your battery runs down in voltage similar to above, its not too bad.

- If you battery runs down in voltage much much much quicker, or at any time drops below 12v... its in a bad state, but it can be saved with a good 3 stage charger and some epsom salts... as long as it has no dead cells. If it drops below 9v fairly easily, it has dead cells

7: Load test (engine battery)

- Make sure everything is turned off inside the van, no lights, door open lights, radios, headlights etc.

- Connect only the van battery. Is there a voltage change? If yes, something is drawing power.
- Start the van (Don't rev engine, leave red alternator light on) whilst you watch voltage on meter. Did it drop to below 12v whilst cranking?

IF YES
Your battery is getting old and needs replacing soon.

If NO
- Switch engine off and restart. Did it drop below 11.5v whilst cranking this time?

IF YES
- Battery is getting old and needs replacing soon.

IF NO
- Battery is fine.


SO what did you find out?

The batteries are isolated from each other
- If one is knackered, it will not draw power from the other overnight or when underload

The SCR is functioning correctly
- Keeping both batteries charged
- Keeping both batteries isolated when appropriate

Roughly what condition each battery is in

Good luck