Leiusure batery troubles

[zend]

Hi,
I have recently become a new proud owner of a T4 California Coach 1998.
I have found out that the gel battery (140 AH) inside is now 20 years old and very much dead. So I have purchased a new one (Varta 190ah LDF, which has the same dimensions). Unfortunately, the car won't recognize there is a second battery (the battery symbol on the Westfalia unit keeps blinking). So I started investigating, reading through the forum but couldn't reach a solution.

Some facts:
The battery is new.
I can tell that it is charged as the previous owner installed a USB charger directly on the battery, and they show good voltage when the car is off (12.5) as well as when it is on (14.2).
Based on the voltage, I can confirm that the battery is charging and the relay is functioning.
When the car is off, the heater and the fridge won't work. When on, they both work.
I checked the DIP switches on the westfalia unit and they are correctly off, on (for traction battery) , off, off).
I checked the fuses and all seems all right ( except for the water pump (3A), which is burned), but the pump goes directly into the 12v stocket under the 220v stocket and functions all the time with no problem (car on or off).
I check with voltmeter and the fuse box behind the driver shows 12.5v on the left side so I guess it should be fine as well.
I also checked the westy unit, but could not find any "cold" place that would indicate any problem.
I did try to restart the unit by pulling out the 1st fuse (5A) I believe.

Finally, when I did all the checking with the voltmeter, the unit stopped showing the water level in the fresh water tank. (Actually, previously it was showing fine, then it stopped showing the level, despite having some water in it (around 10l) and and then finally the symbol disappeared). It laso stopped showing the battery voltage while driving (previously, when on, it showed some value, and when off it showed --:--). Now it only shows --:-- all the time.

Could anybody help? Cheers!




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[sidepod]

I have a feeling you’ve bought a battery that’s too big, too many Amp Hours.
The original unit is/was 140Ah. I think the system is configured around that size.
I proved this to my own cost when I tried fitting a 180Ah. Things just started misbehaving and ultimately the battery died as the charger wouldn’t work properly. The battery appeared to show a healthy voltage but it just didn’t work.
Once I fitted a correctly sized 140Ah all was well.

 

[camper albert]

There is no way of detecting how big a battery is without doing a full charge/discharge cycle. Since any vehicle will stop about half way to save the battery from damage, the vehicle won't know how big it really is. So I can't imagine that is the root cause of your problem.
If I look at the shunt resistor on the picture it has been overheated once upon a time. Is it still ok?

 

[sidepod]

There is no way of detecting how big a battery is without doing a full charge/discharge cycle. Since any vehicle will stop about half way to save the battery from damage, the vehicle won't know how big it really is. So I can't imagine that is the root cause of your problem.
If I look at the shunt resistor on the picture it has been overheated once upon a time. Is it still ok?

I agree but I promise you when I fitted a larger battery things stopped working.

 

[zend]

@sidepod Could I test your thesis by placing in a clasic small lead battery (from the front) and see if it all works?

@camper albert How could I test it?

 

[camper albert]

Reading your story there is a disconnection of your second battery from the system (no power when motor off). That can be in either the positive or negative wire. So I would take out the battery and measure the resistance between the negative battery clamp and the chassis. It should be almost zero. Second I would measure the positive clamp. There should be almost zero resistance from the clamp to the positive wire of some consumer. E.G the fridge or a cigarette lighter socket centre pole.
I assume one of there will show a non zero value. That is the wire where you have to look further for blown fuses or shunts.

 

[zend]

Little update, Yesterday I tried to swap the batteries ano no difference. So I think I can rule out the battery as the main cause. I Have also tested the 220v stocket and this one does not work when car is off. Today I will try to use a camping plug, to see how it behaves.

The water tank just appierd again (without any bars).

On Monday I am bringing the car to an electrician.

 

[sidepod]

The 220v socket won’t work with engine on or off but only when connected to an external supply.

At least you’ve proved my theory wrong which is good.
It maybe a bad earth?

Please keep us updated.