Problems automower 220ac after convertion to li-ion battery

[guyc]

I replaced my NI-NH battery by a Li-ion battery.
After the conversion, I have 2 problems;
1. When the mower is in service, the mower motor is not running. With the test procedure the mower motor is running without any problem.
2 When to automower is in the loading station, loading starts (1,7 A) but stops loading after a short time. The battery stays unloaded. Voltage on the display 25,8 V

Personnaly I think both faults are related to each other, but I'm not a specialist.
I think the voltage from the original transformer (26 V) is too high and the BMS of the battery disconnect the battery..

Probably because the battery is not loaded, the electronic board stops the mower motor. Very strange because at that moment the automower should have to go back to the loading station, but he stays running around.

specifications of the BMS :

5S 15A Li-ion Lithium Battery BMS 18650 Charger Protection Board 18V 21V Cell Protection Circuit

Charging voltage: 21 V
Charge MOS pressure value: 35 V
Discharge MOS pressure value: 35 V
Charging current: 56 A
Continuous discharge current: 15 A
Over current protection: 50/55/60 A
Over current protection delay: 20/25/30mS
Single section since the power consumption: 30uA
Single section between the power consumption: 3uA
Single section over charge detection voltage: 4.18- /4.22V
Over charge recovery voltage 4.05- 4.15 V
Over charge detection delay: 0.5/1.0/2.0S
Single section over discharge detection voltage: 2.75-2.85 V
Over discharge recovery voltage: 2.90-3.20 V
Over discharge detection delay: 0.5-2.0S
Short / over / over current protection recovery short circuit / over discharge / over current protection after removal of load auto recovery
Short circuit protection delay 200/500/600uS
The normal working state of B- to P- resistance: 5mΩ
Continuous 15A current maximum temperature rise: 25 ℃
Working environment (humidity) relative humidity: ≥98% (long-term stability under the humidity)
Working environment (temperature) -30 ~ 80℃(in the lower temperature range of long-term stability)

[chercheur]

Hello,

We are missing a lot of in formation regarding how you did the Li-Ion adaptation.
How to you produce the DC voltage ? Etc...

Tx fpr clarifying.