Solar with GC 680 and Votronic leds

DonGraham · Nov 14, 2023

Hi again, my GC680 has factory solar fitted, which does appear to work. The leisure battery shows 100% on the internal display panel when parked on the drive, and with a voltmeter across the battery I can see an increase in voltage when the sun is out.
My query is, while draining the water using the taps in the electric cupboard a week or so ago, I noticed a flashing led on the Votronic MPP250 unit. The LED flashing is "MPP" and according to the instructions it says "Battery Protection". I have had a look a few times since including when quite dark, and it's always been the MPP led flashing. I have never seen any other LED's such as "Batt. Full". Is this normal? I've checked the DIL switches and they are down down up down, which seems correct for a lead Acid / AGM battery.
The instructions describe 2 types of flashing MPP LED. "Flashing" and "Short Flashing". Not sure what mine is, but it is a flash around ever second, ie count 1001, 1002 etc and it flashes in time.
Any advice appreciated...
TIA

DonGraham · Nov 18, 2023

Hi again, just a quick bump of mesage. I sent an e-mail for advice to Votronic at 'service@votronic.de' but so far no reply.
I would appreciate anyone with a similar setup to mine to have a look in the electric cupboard and see what the LED's are saying on a reasonably sunny day. I have a feeling my Votronic unit isn't charging the leisure battery as it should, but it would be good to have more info for when it goes in for its first service.
TIA
Don

GordonH · Nov 18, 2023

DonGraham said:
Hi again, just a quick bump of mesage. I sent an e-mail for advice to Votronic at 'service@votronic.de' but so far no reply.
I would appreciate anyone with a similar setup to mine to have a look in the electric cupboard and see what the LED's are saying on a reasonably sunny day. I have a feeling my Votronic unit isn't charging the leisure battery as it should, but it would be good to have more info for when it goes in for its first service.
TIA
Don

Best way to really check is with the Votronic Bluetooth adapter. It just plugs in and gives you all the data. Without that the info is pretty limited but attached is the manual for the MPPT which outlines what the lights do. Check the DIP switches are set to AGM1. 165 on the GC600, 250 on the GC680.

GordonH · Nov 18, 2023

Apologies if I’ve answered things you already know.

AndrewCook680 · Nov 18, 2023

@GordonH
is this all you need to Bluetooth to work ?
I think it said you need a screen too which this plugs inbetween that and solar controller , but I wasn’t sure

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiWhLiAwc2CAxVgh_0HHQ00AtIQFnoECBIQAQ&url=https%3A%2F%2Fwww.amazon.co.uk%2FVotronic-Bluetooth-Connector-Interface-S-BC%2Fdp%2FB07MN61BMN&usg=AOvVaw3WDl_1HpDFVc9tVXjEPeV4&opi=89978449

AndrewCook680 · Nov 18, 2023

Communication module for a variety of Votronic devices. The Votronic Energy Monitor consists of a special communication module, which in conjunction with a Votronic solar charge controller with LCD solar computer S

GordonH · Nov 18, 2023

AndrewCook680 said:
@GordonH
is this all you need to Bluetooth to work ?
I think it said you need a screen too which this plugs inbetween that and solar controller , but I wasn’t sure

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiWhLiAwc2CAxVgh_0HHQ00AtIQFnoECBIQAQ&url=https%3A%2F%2Fwww.amazon.co.uk%2FVotronic-Bluetooth-Connector-Interface-S-BC%2Fdp%2FB07MN61BMN&usg=AOvVaw3WDl_1HpDFVc9tVXjEPeV4&opi=89978449

That’s all you need. Works with an app.

GordonH · Nov 18, 2023

AndrewCook680 said:
Communication module for a variety of Votronic devices. The Votronic Energy Monitor consists of a special communication module, which in conjunction with a Votronic solar charge controller with LCD solar computer S

Those are additional bits. You only need the Bluetooth bit that plugs directly into the MPPT and you can see what’s going on. See screenshot just taken

GordonH · Nov 18, 2023

If you want even more info around what’s happening to the leisure and starter batteries it’s possible to use the electronics module removed from a 500A Victron shunt wired across the existing VW leisure battery shunt with a rescaling potentiometer to give you total insight into the charge status etc.

AndrewCook680 · Nov 18, 2023

Thanks Gordon

DonGraham · Nov 20, 2023

Thanks for all the previous information!

Just had a reply from Votronic, see below. It looks as though something is not right with MPP flashing all the time, so reported to VW to check on first service. I fear the worst! Somehow van mechanics and solar power units don't seem to fit together too well!

Dear Mr. Graham,
thank you for your inquiry and your interest in our product range. The MPP solar controller starts charging as soon as the voltage level of the solar panels at the input is approx. 1.5V higher than the voltage level at the output of the on-board battery. Judging by your descriptions(MPP LED is blinking), the solar panels may not perform well or at all during sunshine.

If the MPP LED is flashing during night or without sunshine it’s pretty ok (see page 6 - pilot lamps).

To check the solar power, please proceed as follows:

Check the short-circuit current Isc and the open-circuit voltage Uoc / Voc of your solar system on the open lines of your solar module. Compare your measurement results with the technical information provided by the panel manufacturer. In full sunshine, approximately the same values should be found here. The voltage when connected to the solar charger must be nearly the same as the Voc.

If you have any further question, don’t hesitate to contact me.

Kind regards
Eva Seibert

Technical Support