Battery Charging Issue HELP please

Subject: Assistance Needed with Battery Charging Issue

Good day,

My Off-Gridd Installation is running for 6 year now and I have been struggling with the following issue for a few days.
The battery was deeply discharged (there is still a 48 V / 12 V converter connected) on 2 Pylontech US2000 batteries at approximately 8 % state of charge (SOC), which I now understand under the SOC value lag.

With my low-cost 3 kW generator, I was unable to start a charging process (which has worked previously, several times, although this time with extreme cold).

I then procured a Hyundai diesel generator with 5 kW, which was able to start the charging process, charging at 1,000 W at 0 °C. However, this did not last long and the charging stopped; now the input current is no longer detected at all.

Over the following 2–3 days, I noticed that in the morning I was able to charge again, this time with 10 A set. It also failed again, and eventually the system only charges at 5 A even though 10 A is allowed — until the input current is no longer recognized.

bynow the batterie has 30 % and a temperature10 celsius, so it should work charge normaly.

In the VEConfigurator, the AC input is marked in red, and I do not see any frequencies from the generator.
It is also notable that the AC output suddenly dropped. This could also be due to an incorrect ESS configuration.

Steps already taken:

  • Complete system restart, BUS CAN disconnected and reconnected

  • Batteries re-synchronized, LEDs green

  • ESS Assistant run with and without batteries — no solution

I hope you can assist me with this problem.
I have exported my configuration below.

Thank you very much.

TAB: General

System frequency 50Hz

Shore current 16.0 A

Overruled by remote checked

Dynamic current limiter checked

External current sensor connected (see manual) unchecked

State of charge when Bulk finished 95.0 %

Battery capacity 100 Ah

Charge efficiency 0.95

TAB: Grid

Country / grid code standard Other: not compliant to any grid code standard

AC input 1 Above selected gridcode plus LOM B (safe)

Accept wide input frequency range (45-65 Hz) checked

AC low switch mains off 180 V

AC low switch mains on 187 V

AC high switch mains on 265 V

AC high switch mains off 270 V

UPS function unchecked

TAB: Inverter

PowerAssist unchecked

Inverter output voltage 230 V

Inverter DC shut-down voltage 37.20 V

Inverter DC restart voltage 43.60 V

Low DC alarm level 43.60 V

Do not restart after short-circuit (VDE 2510-2 safety) unchecked

enable AES unchecked

TAB: Charger

Enable charger checked

Weak AC input checked

Stop after excessive bulk unchecked

Lithium batteries checked

Charge curve Fixed

Absorption voltage 52.00 V

Float voltage 51.00 V

Charge current 20 A

Repeated absorption time 1.00 Hr

Repeated absorption interval 7.00 Days

Absorption time 1 Hr

TAB: Virtual switch

TAB: Usage

Virtual switch usage Do not use VS

TAB: Assistants

TAB: Assistant Configuration

Assistants not used

I have resolved the issue. As is often the case, the cause was poor wiring: one phase apparently did not have a continuous connection, which ultimately also explains the observed fault pattern. It explains why initially 10 A of charging current were flowing; after approximately 15 minutes the connection had heated up and the MultiPlus allowed only 5 A, and later no current at all.

The Victron MultiPlus did exactly what it was supposed to do.

Greetz

1 Like