question

sacha avatar image

MPPT 100/30 showing hauting behaviour when being in absorption mode

Hi,

I have installed in my campervan a 315W solar panel + victron MPPT 100/30 + AGM battery 190Ah C10. Everything worked properly during nearly a year. It's been a few days that my MPPT is showing a very strange behaviour when being in Absorption mode.

First of all, the voltage is not kept constant during absorption as it should. The received power keep oscillating between 0W and the maximum power that the PV cell can provide. It looks to me that the MPPT cannot find the maximum power point anymore. Eventually the battery started to make a slight bubbling noise.

I lowered the absorption votlage such that the system could go into float mode and still this strange oscillating behaviour shows up.



Below the configurations and some sceenshots of the status;whatsapp-image-2021-04-17-at-195258.jpeg

whatsapp-image-2021-04-17-at-195259.jpeg

whatsapp-image-2021-04-17-at-1952591.jpeg


whatsapp-image-2021-04-17-at-1952592.jpeg


Could someone help me with this issue? Might it be an MPPT issue, ... ?

Any help woul be very appreciated.


Sacha

mppt smart solaroffgridAGM Battery
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
ripper avatar image
ripper answered ·

I rarely had that. To me it looks like it froze or hung up. Rectifying was only possible by disconnecting both solar and battery and waiting a minute before reattaching. Disconnecting solar or switching charger off via bluetooth did not help. Not sure whether nightfall resets the unit.


Latest software installed? Havent had that in a year.

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

sacha avatar image
sacha answered ·

I swaped the MPPT with a brand new unit and the behaviour is still present. I checked the condition of the battery and it is fine. It really seems that the MPPT cannot impose a voltage to the battery and hence oscillate. The phenomenon happens in float and absorption modes but not when the Orion is in used (connected to the smart alternator of the vehicule).

Does someone have an idea?


2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

pwfarnell avatar image
pwfarnell answered ·

Could there be a poor connection between the battery and the controller so any current flow results in a higher voltage at the controller. Can you measure the actual battery voltage and see if it is the same as at the controller.

1 comment
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

I ve just checked and the voltage at the battery is very close to the voltage at the MPPT output. So it justs keep oscillating. Another strange behaviour is that the MPPT is still driving around 2A in float mode. All the loads have been disconnected. 2A seems high to me for a fully charged battery.


sacha avatar image
sacha answered ·

Hi ripper,

Thanks for showing up. I have disconnected the solar and the battery to reset the unit and nothing changed. I didn't wait for 1 minute before reconnecting them though. Not sure if it is important?

The latest firmware version is installed. Do you think the MPPT unit can be broken?

Or maybe the battery itself? It doubt it to be honnest.



3 comments
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

It could be. The unit needs to be drained of energy. If it was only disconnected for a few seconds it could have had enough juice left in it preventing a full restart.

Yes It could be. But the date has changed when reconnecting so I believe the unit has reset. I will try to swap the MPPT with a new unit and see if it is better

I think it starts a new day fairly easily by just loosing solar