Leisure Batteries draining?

[Loz]

This chart doesn’t correspond to my control panel display readout.

View attachment 53207

View attachment 53208

I don't expect the control panel has been updated since VW moved to AGM batteries.

 

[AlisonF]

You need to insulate that terminal! So I expect the 80A fuse at the front is now blown if that terminal has touched ground.

They’re sending someone out as I type. I’ve also taken pics and emailed the manager.
I am so so so frustrated, I simply am simply lost for words...

 

[WelshGas]

This chart doesn’t correspond to my control panel display readout.

View attachment 53207

View attachment 53208

Try resetting the Control Panel.

 

[AlisonF]

So apologies received from service receptionist, manager and the guy who came to put the battery back - who is the same person who worked on the 12V issue and again today - so hopefully he now has a better understanding of the issue.
The drain test will be with the computer, but he also wants another Cali at the same time to compare with.
Fingers crossed this time next week we will know why the batteries are draining so quickly and be able to fix it under warranty...

 

[VW Guru]

Hi it maybe worth asking them to check the measuring shunt behind the fridge I’ve had 5 T6 calis now with leisure battery issues and found one of the connections to the shunt overheated due to high resistance from a poor fit in the factory a new connector and shunt was required in each case.

 

[MartG]

Their proposal is to fully charge it, and another Cali, have both overnight with heater on and see what the batteries say in the morning on the two Cali’s... so not exactly what I would call a proper drain test...?

Any more advice on how the battery drain test should be conducted would be welcome.

Sorry Alison, I was away at a concert Friday, back today...
Not exactly a controlled, steady load condition test, as you say, but may show up a difference - the other Cali may be in a worse condition than yours, giving your one a glowing report!
Any decent garage should have a dedicated battery load tester - looks like a voltage meter with a large resistor built into the case, pressing a button once connected puts it under a high load and after 10-15 secs, shows it's voltage drop. This gives a rough indication of ability to deliver current / capacity. Ideally, a lower steady load over an extended time, say 24 / 48 hours, would give a better indication of capacity, maybe using a 10W bulb, then measuring voltage would be ideal.
A point to note is, if the rear fuse was blown, it could be the front battery which will be discharged further in use, causing a reduction in it's life, as well as the rear one not getting a charge if low, reducing it's capacity too, so potentially both batteries should be replaced if a fault was found.

 

[AlisonF]

I’ve received apologies from manager, service manager and service receptionist. Also from the technician himself when he came by to put the battery back.
They are now proposing to replace all 3 batteries (two leisure and main engine battery) this week. I’m not sure that is all necessary, but if it solves the issue then great. If not, then will look into what @VW Guru suggested with the shunts behind the fridge.
And it seems they are going to discipline the technician (which I am not comfortable with as feel there as been miscommunication at all levels and no one individual to blame, and I have emailed to say so...)
From one extreme to the other? When just good communication and good service would have avoided any issues?
Fingers crossed, this time next week I can report all is well. How come I don’t believe that...

 

[MartG]

That's good news Alison, hopefully they won't botch the replacement!

I would guess your shunt resistor is fine as the trouble started when it was with them, they shouldn't have disturbed it and it was working before. Keep an eye on the control panel battery state and see how they perform, I'd give them a good test using the fridge & heater as soon as you can.

Martin

 

[AlisonF]

The van went in for the battery replacements on Thursday. I was slightly surprised not to receive any documentation detailing the batteries (as would need receipts, etc. if I sell it). Then I received an email saying the service manager would be sending me a technical email with the results from their tests. This surprised me as I was under the impression they were simply replacing all the batteries.
Decided to wait over the weekend. Drove 90+miles on Friday for agility training and batteries showing 100%. 2 miles Saturday and 100%. Put the heater on level 4 for 10 mins on Sunday to defrost the van and they batteries dropped to 50% (12.2 Volts). So does that mean they didn’t replace the batteries after all?
I’m dumbfounded...

 

[Lightning]

The van went in for the battery replacements on Thursday. I was slightly surprised not to receive any documentation detailing the batteries (as would need receipts, etc. if I sell it). Then I received an email saying the service manager would be sending me a technical email with the results from their tests. This surprised me as I was under the impression they were simply replacing all the batteries.
Decided to wait over the weekend. Drove 90+miles on Friday for agility training and batteries showing 100%. 2 miles Saturday and 100%. Put the heater on level 4 for 10 mins on Sunday to defrost the van and they batteries dropped to 50% (12.2 Volts). So does that mean they didn’t replace the batteries after all?
I’m dumbfounded...

My leisure batteries went completely flat (0%) for a few days at a festival where I could not charge them. They have never been the same since. I can charge them up on a long drive and they immediately drop to 12.2V. Your batteries sound as if they behave like mine. I was told the VW battery test passed but the dealer seemed unconvincing and their technical competency didn’t extend to answering some simple questions about the test.
I think your batteries are probably damaged by the deep discharge they had and as you suspect have not been replaced.

 

[MartG]

. Put the heater on level 4 for 10 mins on Sunday to defrost the van and they batteries dropped to 50% (12.2 Volts). So does that mean they didn’t replace the batteries after all?
I’m dumbfounded...

I would say not Alison, I'm afraid, unless you still have a fault somewhere. They should have shown around 80-90%, 12.6 - 12.7V, the lower value if only 1 battery was supplying and the higher value if both were working, based on the heater drawing 15A for 15-20 mins. Did you read the % / V right at the end of the heating? The battery voltage can recover slightly once the load has been removed, say 20 mins later...

 

[AlisonF]

I would say not Alison, I'm afraid, unless you still have a fault somewhere. They should have shown around 80-90%, 12.6 - 12.7V, the lower value if only 1 battery was supplying and the higher value if both were working, based on the heater drawing 15A for 15-20 mins. Did you read the % / V right at the end of the heating? The battery voltage can recover slightly once the load has been removed, say 20 mins later...

It was definitely 50%, voltage might have been 12.7 - that’s what I made a mental note of but wrote down 12.2V - so I could have noted it incorrectly.
I’ve put on hook up overnight and will see what happens when I put the heater on tomorrow morning before heading off to agility...

 

[MartG]

Is it possible for you to have a look at the rear battery, by opening the cover? You should see if the battery looks new (clean and possibly see a date marking), of course, your original battery may have been clean too!
The dealer could have had some 'older' new batteries which haven't been kept fully charged, they should be kept above 60% ideally for long life. As @Lightning mentioned above, once they are discharged below 12.4 V and not re-charged for a while, they can permanently loose capacity.

 

[AlisonF]

Is it possible for you to have a look at the rear battery, by opening the cover? You should see if the battery looks new (clean and possibly see a date marking), of course, your original battery may have been clean too!
The dealer could have had some 'older' new batteries which haven't been kept fully charged, they should be kept above 60% ideally for long life. As @Lightning mentioned above, once they are discharged below 12.4 V and not re-charged for a while, they can permanently loose capacity.

If I don’t get a good response from them tomorrow I will take a look. I have always kept them charged regularly on hook up and drive a lot. Even when I didn’t drive with back problems last year I regularly had them on hook up and had a neighbour start the engine and leave it running for 15 mins. They were still working fine when I camped in September...

 

[Loz]

I know its a bit after the fact now, but if I asked the dealer to change my batteries, I would have "marked" them so that I knew the work had been done.

 

[AlisonF]

I know its a bit after the fact now, but if I asked the dealer to change my batteries, I would have "marked" them so that I knew the work had been done.

Good tip! I’m still refusing to touch anything whilst under warranty as simply do not trust this dealership.
But I am russling up an old engineering colleague / friend to take along this week as I sadly feel they are not taking me seriously. Even though my engineering qualifications are higher than my friends, but that doesn’t seem relevant at the moment...

 

[AlisonF]

Sunday eve and just received this reply...

Apologies for the belated reply, I am still awaiting VW to come back to me regarding some questions about the algorithm used by the onboard voltmeter.

The tests carried out on the charging system current draw, on the vehicle showed the following
Stage 1; 0-15 Mins 0.9 -0.11 amps
Stage 2; 15-30 Mins 0.03 amps
Stage 3 30+ mins 0.005 amps
All these readings are within specification.

Charging voltages on these systems run at about 14.3 volts, with a resting battery top of charge voltage of an absolute maximum of 12.8 volts. (Theoretically a battery of this type could show a resting voltage of 13.2 volts, but this would need to be un lab’ conditions) (6 x 2.2volt cells)
I will check with VW as to what the calibration of the on board voltmeter is set to for 12.20 volts. If I was testing a battery personally and saw a reading of 12.20 volts, my view would be a 95% charged battery.
Looking at the spec sheet on the aux heater it will work down to a voltage of 7.7 volts.
If 12.70 volts is 100% charged and 7.70 volts being classed as 0% charged, 50% should be about 10.20 volts, but I will need to verify this with VW.
It could be that we are chasing an issue with the onboard meter rather than any charging issues.

Once VW respond I will be in touch.

Kind Regards

 

[MartG]

Sunday eve and just received this reply...

Apologies for the belated reply, I am still awaiting VW to come back to me regarding some questions about the algorithm used by the onboard voltmeter.

The tests carried out on the charging system current draw, on the vehicle showed the following
Stage 1; 0-15 Mins 0.9 -0.11 amps
Stage 2; 15-30 Mins 0.03 amps
Stage 3 30+ mins 0.005 amps
All these readings are within specification.

Charging voltages on these systems run at about 14.3 volts, with a resting battery top of charge voltage of an absolute maximum of 12.8 volts. (Theoretically a battery of this type could show a resting voltage of 13.2 volts, but this would need to be un lab’ conditions) (6 x 2.2volt cells)
I will check with VW as to what the calibration of the on board voltmeter is set to for 12.20 volts. If I was testing a battery personally and saw a reading of 12.20 volts, my view would be a 95% charged battery.
Looking at the spec sheet on the aux heater it will work down to a voltage of 7.7 volts.
If 12.70 volts is 100% charged and 7.70 volts being classed as 0% charged, 50% should be about 10.20 volts, but I will need to verify this with VW.
It could be that we are chasing an issue with the onboard meter rather than any charging issues.

Once VW respond I will be in touch.

Kind Regards

???

I have no idea what the stage tests are, charging currents? which have no bearing on the battery capacity state. Charging voltage is correct, around 14.3V.

I would say that the voltage range for a Varta AGM battery would be (no load connected);
12.8V 100%
12.6V 75%
12.3V 50%
12.0V 25%
11.8V 0%

I agree that the display isn't particularly accurate.

If the aux heater took the battery down to 7.7V, the battery would very quickly be U/S!

 

[Loz]

I posted this earlier.


AGM batteries mustn't be left below 10.6 volts or that are not recoverable.

The camper control module may need a few cycles to get the percentage correct.

 

[Lightning]

???

I have no idea what the stage tests are, charging currents? which have no bearing on the battery capacity state. Charging voltage is correct, around 14.3V.

I would say that the voltage range for any AGM battery would be (no load connected);
12.8V 100%
12.6V 75%
12.3V 50%
12.0V 25%
11.8V 0%

I agree that the display isn't particularly accurate.

If the aux heater took the battery down to 7.7V, the battery would very quickly be U/S!

Just my 2 cents and I'd be happy if anyone was to contradict or agree, but I'm sure Clarks man doesn't know his batteries!

VW Guru has stated in the past that the VW test does use charging current as an acceptance parameter.
The values he has given are very very low currents, which you would only see on an almost fully charged battery. I would ask them to explain: What are the stages? What are the allowable limits for each stage? What does the test process entail?
The display percentage is hopeless but the voltage on the display is accurate. The heater turns off when the voltage gets down to about 11 V to 10.5 V on my van.
VW are very reluctant to change batteries under warranty in my experience. I know my batteries have degraded significantly but they still passed the VW test...

 

[Lightning]

One more question you could ask them if they still refuse to change them is:
How does the remaining capacity of each battery compare with its specification?
I think the VW batteries are specified as 115Amp hours each. So what are they now? This just means that they theoretically should be able to continuously deliver 11.5A for 10hrs or 115A for 1hr for example.
If they cannot tell you what their actual capacity is, then how have they demonstrated that the batteries are ok to your satisfaction?

 

[WelshGas]

One more question you could ask them if they still refuse to change them is:
How does the remaining capacity of each battery compare with its specification?
I think the VW batteries are specified as 115Amp hours each. So what are they now? This just means that they theoretically should be able to continuously deliver 11.5A for 10hrs or 115A for 1hr for example.
If they cannot tell you what their actual capacity is, then how have they demonstrated that the batteries are ok to your satisfaction?

80 amp hour batteries.
these are the exact Varta replacements. The batteries supplied to VW by Varta are black. Those sold by Varta are silver.

LA80 Varta Professional Dual Purpose AGM Leisure Battery 840 080 080

LA80 VARTA Professional Dual Purpose AGM Leisure Battery <i>Innovation with Purpose, Premium Experience, Powerful History</i> VARTA was founded in 1887 Germany, and was established fully in 1904 by delivering the first electric vehicle battery, famously driven by Thomas Edison. Soon after, VARTA...

www.tayna.co.uk

 

[Lightning]

80 amp hour batteries.
these are the exact Varta replacements. The batteries supplied to VW by Varta are black. Those sold by Varta are silver.

LA80 Varta Professional Dual Purpose AGM Leisure Battery 840 080 080

LA80 VARTA Professional Dual Purpose AGM Leisure Battery <i>Innovation with Purpose, Premium Experience, Powerful History</i> VARTA was founded in 1887 Germany, and was established fully in 1904 by delivering the first electric vehicle battery, famously driven by Thomas Edison. Soon after, VARTA...

www.tayna.co.uk

Thanks, I’ve just ordered a pair. This thread has reminded me how annoying my batteries are.

 

[Lightning]

Battery care advice from the Varta site. It says if the voltage drops below 12.4V then sulphation begins.


1. Never leave your battery in a discharged state
When a battery has been fully charged it can quite happily be stored away for 2-3 months. However when a battery is flat, storing it for this period would almost certainly damage it beyond repair.
The reason behind this is a chemical process called sulphation. When a battery is charged this chemical process cannot take place. However, when the battery's voltage falls below 12.4V this process begins. The process causes sulphur crystals to form on the lead plates inside the battery, which in turn increases the battery's electrical resistance. The longer this process is allowed to continue the worse the effect. Eventually the battery will become so electrically resistant, that you will be unable to charge the battery, let alone draw power from it.
If this process is caught early you may be able to salvage the battery using a battery charger with a pulse charge function. This will partially break down the sulphur crystals but the battery will never reach its full capacity again.
Remember that if your battery fails due to sulphation it will not be covered under warranty. This kind of failure is classed as damage caused by the user through neglect.
2. Never overcharge your battery
Although you must always keep your battery as charged as possible when not in use, you must never overcharge it. Overcharging will cause the battery to heat up and its electrolyte will start to evaporate. In turn this will cause the battery's plates to break down, severely reducing the battery's ability to yield power.
Overcharging can be caused by a faulty regulator on a vehicle's charging system or by a manual charger being left on continuously at a high charging rate.
Fortunately, most chargers these days are now automatic and will turn themselves off once the battery has reached the end of a charging cycle.
This type of damage is also not covered under warranty, as the battery is clearly not at fault.
3. Avoid deep discharging when possible
Everybody knows that all batteries will deteriorate over time, and will eventually have to be replaced. Every time you use your battery then recharge it, its performance is ever so slightly decreased. This cannot be avoided. However, the severity of this decrement can be limited.
The way to achieve this is to not discharge your battery too deeply. Deep discharging causes the performance decrement to be more severe. Therefore once you have used the battery for the day, it is best to recharge rather than use it until it becomes flat.
Obviously, in the real world this is not always possible as the battery may be fully drained with one days use. But when you can, recharge the battery before it's fully discharged.

 

[MartG]

12.4V is around 60%, which they recommend staying above for long life. Any lower will of course work fine but with progressively reducing cycle life. The more you keep the discharge above 60% AND / OR re-charge as soon as possible, the better life expectancy. Sulfation occurs when the cells discharge at ANY point below full charge, minor & reversible when above 12.4V, while below 12.4V then more likely that permanent sulfation occurs, getting progressively worse with lower voltage and longer time.

That's life for all lead acid cells...

edit - just found this interesting article on load testing... https://www.jefftk.com/p/load-testing-a-battery

and this youtube vid -

Alisons problem will be proving the good condition of the batteries prior to the dealerships 'intervention' and the fact that batteries are a wear and tear item, so the original 80Ah capacity will have inevitably dropped during normal good use over the years...

edit 2 - thinking of the dealers logic(!), the aux heater may well operate at 7.7V, but that is the heaters specs voltage range minimum, nothing to do with the vans 12V system.