Coachman VIP with Truma Solar setup overcharging

Yes it is a known issue with VIP owners.You have to contact your dealer for a quick recalibration or programming of the indicator panel.

Hi

There are three areas that are a problem.

One the early control panels were set with a low warning level re overcharging. A new panel with higher level has been fitted. Still shows 15V and warnings re dealer recall.

Two On removal of the Solar fuse the level drops to 13.2 v from 15v. Why is the regulator not dumping the overcharge?

Three the voltage measured with a multimeter at the battery is 13.2v and 15v so the battery is receiving the charge even though it is fully charger? Why and is this damaging the battery.

Peter

Might be worth setting the controller to gel battery, this usually charges at a lower voltage.

Seeing 15 volts or even a little above on a battery under charge is in itself not a reason for concern. It depends on what part of the charging cycle the battery is undergoing and the sophistication of the charger.

It is bad news if once fully charged it does not back off to a typical float level of 13.2  to 13.4 volts.

See the section on " Battery Charging" part down the page here:

https://www.solar-electric.com/learning-center/batteries-and-charging/deep-cycle-battery-faq.html#Battery%20Voltages.

It is also to be expected that on pulling the charging supply fuse the battery, that directly before was under a significant charge will show far more volts than the 12.7 to 12.9 volts a fully charged battery once rested should show. There is a so called "surface charge" that holds up this higher voltage, it will decay over time or if subjected to a reasonable load.

With both my Morningstar solar controllers I occasionally record just over 15 volts, but still have achieved exceptionally long life from the batteries each is used on.

Thank you

That is how I understand it.

I agree 15v charge is ok but not what appears to be constant? The truma regulator is supposed to charge for 2 hours a month a 15+ v to de sulphurise the battery, but it seems to be constant. This morning it was 14.6v which dropped to 13.4v on removing the fuse. It does not seem to be dumping. Unless this is the surface charge that you mention. But the control panel has a warning over 3 screen that there is a overcharge that it will damage the battery and contact the dealer who is baffled. Feel a bit like a bouncing ball between Coachman who say they don't have a technical manage! Truma who deny its a problem,! The control panel manufacturers who have replaced the panel but no change and the dealer who is stumped.

Are you convinced the battery has reached fully charged, and so ought to have dropped from these higher levels into the float mode? The solar could well be capable of charging it to a higher capacity level than the van's inbuilt charger, and what you are seeing is it simply be completing a full charge. In built chargers often don't fully recharge batteries, not being that sophisticated.

I would be inclined to measure the current, expecting this once fully charged to be minimal,

That "surface charge" will hang in for some hours after disconnecting from a charge; leave it at least 24 hours or use the mover over a short distance if needing to top it off quickly; then see its resting voltage.

The van has been in store for several weeks, so i assume that the reading with a multimeter directly off the battery with the fuse out of the solar input should be 12.7v? not 13.4v and with the fuse in 15v.It must be fully charged I think.

The only output is the Alarm and what appears to be a display on the control panel indicating a overcharge before the panel is switched on or any drain turned on. Interestingly the Truma rep was interested in the fact that there was a continuous draw on the systemm. But surly all modern vans have such?

But why when the solar is connected fuse in does the reading at the control panel (Replaced) read 15V but on turning on the panel and a light drop to 13.4V?

If it has been on charge, and fully charged then on disconnection of that charge it will be way over 12.7 volts, as said charging leaves a superficial "surface charge" which will take a fair while to naturally dissipate.

It can be wiped off quickly when it takes a large load, say like working a mover. If that is brief then despite the high load the duration is short very little energy is taken and so the battery will still be "all but full".

I suspect turning on the light dropping from 15 to 13.4 hints the 15 volts is there with no associated current.

If it sticks up at 15 volts, which is suggesting the battery is being seen by the controller as not fully charged, I would be trying to put a different known good and fully charged battery there to see it that gives the same issues, given three or four hours. But then I have several batteries to hand, which might not be so in your case.

Brand new battery?

But just again there is a sergeant Coachman fitted alarm that draws a small level all the time when on, and the panel has this pre display? 

Could this be fooling the regulator?

I have had the regulator checked by truma. OK Also the control panel manufacturing company have replace the panel as they did have in the early 2019 supply where the warning level set too low.Hopefully the new one is set ok but it's still complaining.

Its a little concerning when every time you check the first three panel screen say Overcharge,May damage your Battery and Contact your Dealer?

Thanks for your help appreciated. 

Just wondering if you ever resolved the issue which was causing the warning messages on the control panel?  

I have recently purchased a new 2019 Coachman VIP 575 and I continually get the same 3 warning messages which say Overcharging, May damage battery, Contact dealer.  The dealer has attempted various fixes regarding re-wiring of the solar panel, and raising the calibration for the limits on the control panel, but they remain baffled as the problem with the warning messages still occurs each time I tow the caravan.