Leisure Battery Circuit Issues

[Gavinskii]

10 minutes ago was at 8:30pm. No solar energy.

12.5 volts is 0.1 volts from full for a leisure battery at rest.

Your battery is 99% full. The fact that the VW panel says 75% is not true. 12.5 volts is small a fraction off full.

As I said above, I don't know how the VW panel calculates "full", but I can tell you with 100% certainty, 12.5 volts is as near to full as possible without being 12.6 volts. I imagine the VW system sees 13.8v as "full" - which is true, but only under charge.

You have had your fridge running all day and more, and your battery is full at 8:30pm in the evening. Which seems ideal.

You have emailed me regarding the AGM batteries. AGM batteries are charged with the same profile as "sealed" lead acid batteries. You can also use the "gel" profile as this is the same, except it skips the equalisation charging phase.

Ok Roger, thanks you are convincing me that maybe my Cali isn't sick!

Out of interest how do I check / change the cell type on my solar set up - just to make sure I am optimised?

 

[MattBW]

One quick question, did you charge both of your new batteries up fully before installing them? Always a good call for 2 batteries as it can impede charging and effect battery life if they are of slightly different voltages before installation.

 

[Gavinskii]

One quick question, did you charge both of your new batteries up fully before installing them? Always a good call for 2 batteries as it can impede charging and effect battery life if they are of slightly different voltages before installation.

Yes Matt, as per original post!

I bought 2 x new upgraded 100w batteries (the ones I took out looked very recent so I don't think in hindsight they were shot), charged them on the hook up cable for 24 hours then drove 40 miles to my UK destination

Following Roger's response regarding expected percentages for "real" state of battery - I am a lot more relaxed about it. I went out and checked my central panel at 8am this morning, and it was already back up to 100% and 12.8v having left the fridge on all night

My hope is that the "newish" looking batteries I replaced were in fact in a poor state as perhaps the previous owner wasn't keeping the batteries regularly charged (something which my solar installation should overcome).

 

[Roger Donoghue]

You can easily kill even new batteries by leaving them under 9v for extended periods.

 

[Dean Oldfield]

My display showed 60% after 5 days on solar however turning the engine on for 1-2 mins max, reset this back to 100%. Don't think a small engine charge can max out the battery so assuming this resets the calculation?

 

[marchugo]

Hi Gavinskii,

I just stumbled upon this two year old thread. From your profile I see you have a 2006 Cali. In these years the charge controller for the hookup loading was built under the fridge. The controller has a safety shut off mecanism that stops charging when the controller gets too hot. This is often the case when:
- hot weather
- charging the batteries
- fridge is working very hard.
The room under the fridge is too small to ventilate, so the charge controller will simply shut off itself.
Solution is to ventilate that area (cupboards open everywhere), put the van in the shade or make shade at the outside where the fridge is inside.
If I remember well this problem was tackled by VW around 2012, by moving the charge controller to the room above the battery in the back.

Don’t know if this covers your problem, but many Cali owners with vans from these years suffered from this heatwave under the fridge.

Regards from Amsterdam,
Marc.