Leaking current from leisure battery

[rjurgens]

Hello,

Does anybody how to check where current is leaking from the leisure battery? After I fully charge it by power cable, then the leisure batteries run close to flat in a couple of days. The car is one year old and according to the dealer, the batteries are still in good shape. I have quite something about electronics, but where can I measure the current running?

Regards, Rudolf

 

[yossarian]

You can measure the current to the nearest Amp on your control panel. More precision is available on the the canbus.

What does your control panel say?

 

[rjurgens]

It shows the picture below. Do I need a special tool to measure the canbus, or does a regular volt meter suffice?

 

[rjurgens]

The car went to the VW dealer for it today, but they claim even a regular USB cable can wake up the converter and draw current (when only the cable is attached next to the sink). But I’m having a hard time believing that

 

[yossarian]

It shows the picture below.

Your current draw looks normal.

Do I need a special tool to measure the canbus, or does a regular volt meter suffice?

You need a special tool. It's a data network like ethernet.

I suggest you start by checking your cube fuse which can be done with a volt meter. Read this thread and let us know how you get on and ping back if you are still stuck after.

 

[yossarian]

The car went to the VW dealer for it today, but they claim even a regular USB cable can wake up the converter and draw current (when only the cable is attached next to the sink). But I’m having a hard time believing that

I have cables plugged in there all the time with no noticeable increase in quiescent current.

 

[rjurgens]

I’m not sure if the cube fuse is my problem, as right after taking taking the charging cable out of the van, it shows full bars on the display? With a broken cube fuse, you seem to be having half bars in that case, since one leisure battery is not working?

 

[yossarian]

I’m not sure if the cube fuse is my problem, as right after taking taking the charging cable out of the van, it shows full bars on the display? With a broken cube fuse, you seem to be having half bars in that case, since one leisure battery is not working?

Quite possibly not, however around 80% of electrical problems seem to be the cube fuse. It takes about 10 minutes to check.

My van has USB As fitted at that location and simply plugging in a cable will not affect the load. I don't see a microswitch in there either. Unless your charging cable has some electronics or damage to it there should be no way it can affect the load.

 

[GrumpyGranddad]

It shows the picture below. Do I need a special tool to measure the canbus, or does a regular volt meter suffice?


View attachment 102947

As an aside, I notice your display shows >60 hours but the battery graphic doesn't show as full. Mine was showing this last week for the first time ever. When in for a service earlier this week I mentioned it and was advised by the Master Technician that there is a software update to fix this. Had the upgrade done and now all hunky dory.

 

[sidepod]

Pull all of the camping fuses out (fridge/heater/lights/sockets etc) and see if the parasitic draw clears. Replace them one by one and recheck each time to establish which cct is causing the drain.

 

[yossarian]

Pull all of the camping fuses out (fridge/heater/lights/sockets etc) and see if the parasitic draw clears. Replace them one by one and recheck each time to establish which cct is causing the drain.

Except that -1A with the control panel screen on is the normal reading.

 

[Resfeber]

Except that -1A with the control panel screen on is the normal reading.

Talk about amp inflation, the T6 display is 0.2 amps for control panel use only.

No chance any cupboard lights accidentally left on although unsure in T6.1 are they switched via the control panel or switches in the end of the kitchen unit behind the passenger seat?

 

[sidepod]

Except that -1A with the control panel screen on is the normal reading.

Get the ammeter out then.

 

[yossarian]

On mine I see 0 / -1A on the display and 450mA or so reported on the canbus. The control panel could use a little more precision.

 

[kurienp]

Pull all of the camping fuses out (fridge/heater/lights/sockets etc) and see if the parasitic draw clears. Replace them one by one and recheck each time to establish which cct is causing the drain.

Agree. In the absence of any tools or additional methods, I would also do this.

 

[dspuk]

Been a long time since I had to fault find a flat battery in anger, but it was always a PITA. For a one year old van the dealer should do the hard work for you on this - it’s not normal behaviour and your Cali is warranted. Why we buy factory

The one thing that you can say is it’s something behind the drivers seats as it’s leisures only and not the main battery.

The best advice here I can see is to pull fuses and see if the draw drops. Clearly something is connected. Things to check your side is are there any lights on that you can’t see - inside the cupboard is a fave, or the one on the rear door. They can both be on and it’s not obvious. They will eventually drain the battery.

A USB cable can cause a draw, but only when connected to a phone else we’d have a lot of flat car batteries.

Other things I can think about are things like dashcams or Solar, but as you have not mentioned anything extra assume they don’t exist.

 

[sidepod]

Not the old “bendy light in the roof left on” trick?

 

[WelshGas]

Stuck microswitch on the Inverter?

 

[AlanC]

My thought too.

The 12v DC - 240v AC Inverter socket is powered by the leisure batteries. There is a micro switch in the plug socket that switches it on when anything is plugged into it, even if you just have an adaptor plugged in with nothing connected to that, the Inverter will be running and draining the leisure batteries.

Alan

 

[rjurgens]

Okay, something is really fishy here. Checkout the display right after one day of charging:

and now check what the display says 1 day later, with zero usage (no lights, refrigerator, heating)



I brought it to the dealer but they could not find anything. I'll look more in detail to the post above because you guys are of great help!

 

[WelshGas]

Okay, something is really fishy here. Checkout the display right after one day of charging:
View attachment 103109
and now check what the display says 1 day later, with zero usage (no lights, refrigerator, heating)

View attachment 103110

I brought it to the dealer but they could not find anything. I'll look more in detail to the post above because you guys are of great help!

Don’t forget Battery output/capacity drops as the temperature drops.
according to your photos there is a - 3.5 c temperature difference between the two measurements.

Lead acid battery charging in cold weather - Victron Energy

This blog covers lead acid battery charging at low temperatures. A later blog will deal with lithium batteries. Charging lead acid batteries in cold (and indeed hot) weather needs special consideration, primarily due to the fact a higher charge voltage is required at low temperatures and a lower...

www.victronenergy.com

Cold Weather And Your Batteries. - Off Grid Ham

If you have not properly accounted for cold weather, then your equipment will let you down when you may most need it.

offgridham.com

 

[andyinluton]

and now check what the display says 1 day later, with zero usage (no lights, refrigerator, heating)

View attachment 103110

I brought it to the dealer but they could not find anything. I'll look more in detail to the post above because you guys are of great help!

Being pedantic thats a day and a half - using those figures you've lost in round terms 60Ah of charge in 36 hours so on average about 1.7 amps is being pulled, at 12v thats about a 20watt load.

In terms of lights - thats the same as a brake light or 4 interior lights, you would see them so can be ruled out.

Waterpump - if pump was spinning without water for that long it would have burnt out.

Fridge - if you sit in silence in the van you can hear a fridge running so you should be able to rule that out.

Radio / can bus not shutting down - I would expect to flatten the starter battery not the leisure ones.

Aftermarket tracker / dash cam / alarm?

Inverter - sounds possible, to test it without messing around undoing things, just plug in an adapter, if the inverter is not your problem that will make the discharge even worse, if it doesn't make it worse it would suggest you've found your problem.

 

[sidepod]

Okay, something is really fishy here. Checkout the display right after one day of charging:
View attachment 103109

and now check what the display says 1 day later, with zero usage (no lights, refrigerator,

So repeat the above with all fuses removed and see what happens.

 

[rjurgens]

Being pedantic thats a day and a half - using those figures you've lost in round terms 60Ah of charge in 36 hours so on average about 1.7 amps is being pulled, at 12v thats about a 20watt load.

In terms of lights - thats the same as a brake light or 4 interior lights, you would see them so can be ruled out.

Waterpump - if pump was spinning without water for that long it would have burnt out.

Fridge - if you sit in silence in the van you can hear a fridge running so you should be able to rule that out.

Radio / can bus not shutting down - I would expect to flatten the starter battery not the leisure ones.

Aftermarket tracker / dash cam / alarm?

Inverter - sounds possible, to test it without messing around undoing things, just plug in an adapter, if the inverter is not your problem that will make the discharge even worse, if it doesn't make it worse it would suggest you've found your problem.

do you mean the 220V inverter?

 

[rjurgens]

I just checked the 230V socket and there is a green light burning there. Is this normal behaviour or does it mean the inverter is drawing current and is engaged?