solarsimon avatar image
solarsimon asked

MultiPlus II Absorption

I have a backup system consisting of:

  • MultiPlus II 48/5000/70-50
  • Cerbo GX
  • BSL Battery (B-LFP48-135E) - connected to GX

System is up and running.

My experience is limited, but I have a concern - the MultiPlus stays on "Absorption" even though the battery is charged to 100%. Been like this for several days now. Is this normal? To confirm, grid is on and load is less than 1KVA.

Also seeing the Inverter LED on the MultiPlus come on from time to time.

I'll try to upload video soon.

Multiplus-IIESSLithium Battery
1 comment
2 |3000

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

jacobjned avatar image jacobjned commented ·


Kindly asking if you have setup an ESS programme as well? As this may explain why you see the Mains On LED and Inverter On LED flash together at times.

Over the absorption LEDs, I am quite sure it is normal with most type of in-built BMS controlled Lithium Batteries. Their absorption voltage and float voltage settings are usually very close by that the difference between two is the same (0.2V difference between float and absorption in VE.Config Charger tab settings). So you may see it jump to float at times but for a very short time, and when that happens, SOC values would have to be above 95%+. Therefore, in the order of sequence, absorption stage is before float stage, which is why the LED would glow more often than the float LED.

0 Likes 0 ·
2 Answers
nickdb avatar image
nickdb answered ·

You tagged ESS, did you load the assistant? If so, why, since this is a backup power system without solar.

Make sure you go through the setup guides for BSL, the 135AH is new, it isn't listed yet on the victron compatibility guide so ask your supplier for the relevant guide to check it is configured right.

They generally all have the same settings but it is worth checking.

There is very little difference between float/absorb anyway (0.2V), wouldn't lose sleep over it.

Be aware, they recommend 2 modules for a 5kVA inverter, if you push the system you are really at/beyond the pointy end of that pack's performance.

2 |3000

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

solarsimon avatar image
solarsimon answered ·

Thank you for the quick responses.

I forgot to mention, but I also have ET112 energy meter installed. The plan is to expand the system with solar panels and charge controller.

I believe ESS Assistant was activated by the installer.

Thank you very much, I will check about the compatibility and sizing of the battery. I wanted the Solar MD SS4074, but I believe they are no longer available - I was supplied with the BSL instead.

I am new to Victron and I was expecting the charger to switch off when the battery is full and the mains is on ☺️ sounds like the charger remaining on is normal though.

Thanks again for the replies.

1 comment
2 |3000

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

nickdb avatar image nickdb ♦ commented ·
Perhaps remove the assistant from the multi until you are ready with solar, it is probably just confusing things.
0 Likes 0 ·