question

francesco avatar image

Agm victron 110ah solar charging absorption time

The article say:

"" "full charge is reached when the current decreases to 3–5 percent of the Ah rating. A battery with high

My new victron 110ah, is daily discharged with 15/ 20% DOD(12.6 open circuit voltage).

After various charging tests with different absorption times, these are the results :

absorb 2A at the ond of 1hr of absorbtion at 14.4v. After, the current drop to 0.8/ 1A at the beginning of floating at 13.8v. And after 4hr of floating decrease at 0.4 A.

If I try to extend the absorption time to 3hr (maximum allowed by my mppt controller), the current does not decrease less than 1.5 / 2 A.
In my opinion it means that it is fully charged with 1 hr of absorption, and with 3 hr I am overcharging it by generating only gas.
Other than that, I measured the open circuit voltage after 24 hours of recharging, and it is 13.14v.
Both with 1 hour of absorption, both With 2 hours of absorption, and with 3 hours of absorption.
What should I do?
VRMmppt chargingAGM 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.

1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

Given your history it seems unlikely that you will ever understand basic, or more complex theory regarding battery care and maintenance.

Batteries are consumable devices. Batteries will always eventually wear out. Be it too hot/cold an environment. To high a discharge. Too high a charge rate.

THERE are literally dozens of things that will reduce your batteries LIFESPAN.. Choose which ones you can control, and mitigate the others as best as you can.


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.

My dear .... maybe you don't know that I have carefully read tons of books and articles and manuals of many brands (Victron, epever, nds, cbe .....) on battery theory, solar charging and charging from A.C. And various brands contradict each other on fundamental aspects(for example absorption time). All the variables you mention (temperature, peukert coefficient, etc etc) I know perfectly well, maybe better than you? I do not know.... In fact, I ask what I do not know, which is the time of absorption. it's just what I have doubts about. I have brought my real, practical and very precise examples with all the data necessary to give an answer. While here only general and evasive answers arrive. Honestly it is the first forum on which I happen ... I will turn elsewhere for this question. If someone knows how to answer, he can answer, if he doesn't know, or doesn't understand my question, perhaps for the language of google translate ... let him do without it.