question

amcfarl avatar image
amcfarl asked

Distortion in charge mode

I am nearly 79 and have little experience of this sort of installation having had 2 different installers who walked away from their attempts to get it working properly, (probably due to their lack of knowledge) leaving us in the lurch with a half working system which as laymen we have tried (not too successfully) to understand. We have a Multiplus 2 charging 2 paralleled 16 cell 10kWh Meritsun batteries which has 2 problems; First it charges OK for both our 3.6kWp solar and the grid but never discharges below 39% (using a Pace BMS or Victron setup) and this is obviously wasting battery capacity. Minimum SOC is set at 15%. The battery SOC values do not tie up with the Pace or Victron values very well. I heard there is Victron firmware available for 16cell batteries which might cure this problem, so how can this be obtained and loaded?

Second the 4kW charge mode is affecting clocks (including changing the time setting in our zappi charger) and causing them to run fast and triac controlled incandescent lighting to flicker badly presumably due to waveform distortion (there is a 200m heavy duty line to the grid connection transformer); can a capacitor bank be added to the line to cure this problem? If so what size should it be?

Thanks in anticipation.

Lithium Battery
2 |3000

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

2 Answers
mvas avatar image
mvas answered ·

Which device is preventing the Meritsun cells from discharging below 39%? Is the BMS on the Merritsun cells disconnecting from the Multiplus? Is the voltage on one cell too low?


2 |3000

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

amcfarl avatar image
amcfarl answered ·

Thank you mvas. I'm afraid don't know enough about the system to be able to say which is controlling the battery, but it looks like selecting either gives much the same result; it never gets below 39%.There are 2 10kWh batteries in parallel; the master battery has the range from 3.024V/cell to 2.992V/cell and the slave has 3.034 to 2.987. They seem to charge OK from grid or solar with the SOC set in the ESS menu at 90% and the voltage in the DVCC at 54.1. This allows the actual batteries to reach about 94.5%. I'm scared to set these any higher in case I overcharge them and do damage or cause fire. At my age I just don't know enough about batteries and chargers as I had expected to rely on the so-called informed installers to get it all to work but they are gone without a trace....

2 |3000

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

Related Resources