question

izzy010568 avatar image
izzy010568 asked

MPPT Cycle - reaching absorption twice a day

b6f0c545-7a6c-4392-b622-2f1a03af001e.png e4573606-de72-4398-bb02-0fe3d915a211.png 1fd2741d-7fd0-4f7d-aeca-e29ee258f8f0.pngImage Caption

Today for the first time this year (system we inherited in our truck 6 months ago) we achieved absorption via solar and dc-dc charging - I saw this when checking MPPT on app when driving.

About an hour later when we were parked up I noticed that a new day had started before/as the system moved into float - and it seems it then went back into abs.

On the screenshots yesterday and today, both are actually today.

We’ve had problems with the system starting a new day in the middle of the day before, and couldn’t find a fix, so learned to live with it. But obvs, don’t want to be going to absorption twice in a day now we’re getting good solar.

I reckon the MPPT is around 10-12 years old (connected via dongle) - is it on the way out?

My other theory is something to do with re-bulk although I don’t really understand it :)

Any ideas on a fix?

MPPT Controllers
1fd2741d-7fd0-4f7d-aeca-e29ee258f8f0.png (479.7 KiB)
e4573606-de72-4398-bb02-0fe3d915a211.png (492.5 KiB)
b6f0c545-7a6c-4392-b622-2f1a03af001e.png (325.2 KiB)
2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

kevgermany avatar image kevgermany ♦♦ commented ·

The day recognition problem is odd. Do you have extended periods of deep shade or panels being disconnected?

0 Likes 0 ·
izzy010568 avatar image izzy010568 kevgermany ♦♦ commented ·
No. Yesterday we had full sun all day. Panels are never disconnected. We did go through a 2km tunnel at some point, Maybe took 3-4 minutes at most.
0 Likes 0 ·
1 Answer
Paul B avatar image
Paul B answered ·

Please make sure that the MPPT has the latest software installed.

but kevgermanys comment re high shade etc - the new should trigger when the MPPT thinks that its night time - this is done by a reduction in sun to 0 volts.

So also check ALL your panel connections as you could have a brocken/fractured wire and thus the reg then thinks its now night time again - or a connection that say looses connection when you go over a bump - look for that sort of issue


1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

izzy010568 avatar image izzy010568 commented ·
Thanks, we’ll take a look. We’re in Georgia (country) right now and the roads are shocking so it could well be that.
0 Likes 0 ·