Recent content by Romeo77

The real problem of BYD is fact that they using different approach to balance pack and that fails almost always They BMS look for highest voltage cells at 100% charge, write down their numbers and then discharge them for up to 17 hours when car used Do match how much cells can loose if discharge...

Only warranty for full pack 8 Years if degraded to 70% SOH this cell to pack almost impossible to dissasemble for single cell replacement all glued to base and this long prismatic cells might be deformed easely !!! Now the weather changed and with higher temperatures pack again get 185 mV; damn...

We can`t disable either bottom (if it exist ) or top balancing in case of BYD at least, i think temperature play not last role when it below +25 degree because if temperature varies across pack when cold that greatly changes internal resistance and in my case almost always battery get...

Percentage you say....... Sorry i not belive in percentage displayed by BMS after what i seen happens when battery calibration done on pack with huge imbalance. If you use Car Scanner loock on high and low voltages of cells when you discharging lower then 10%, highly likely when you reach 0% you...

You probably see calendar degradation that occurs to LFP battery regardless of usage.

That little solar panels will not give enough power to ramp up voltage on 12V battery to unsafe range for DC-DC converter; they provide 3-5 watt only. Problems with the DC-DC converter may occur if we connecting an external charger without disconnecting the battery from car; that can at some...

Actualy calculating amp hours with nominal voltage to get kWh just not right because voltage is not constant it changes. almost all time during charging LFP battery stays at same but not nominal voltage in my case of BYD with 126 cells in series and 11 kW OBC i see in car scanner ~420 v with...

I want do warn about charging 12v battery connected to car. This can damage dc-dc converter !!! If charging absolutely needed better to disconnect negative lead before doing that.

That delta i catch at the moment of charging stops (and that delta also stored in BMS for each full charge cycle), then it falls quickly to 87 now, and after 10 minutes of car started it’s already 33 mV, nope BYD balancing cells also when discharge of battery happens in time frame of 17 hours...

This from repair manual for my car about 90mV at 50% , wish to everyone not to reach such situation !!! Meanwhile my battery balancing cells better every cycle, who that idiot that did such dumb balancing procedure in BYD 😡 Now after i found how it works i see 123 mV at moment of finish...

Usually SOH that tech can see during service is from OEM tablet And may differ from what we can see in Car Scanner That because almost always real cells capacity higher then advertised but degradation in OEM tablet judging by comparing advertised and nominal capacity not from factory capacity...

There is a difference between balancing strategies on these two brands !!! On my Atto 3, OBC uses constant power, all it cat get from power source, until “100%” SOC - i.e. until any of the 126 cells reach HVD set voltage of 3.75 V. Then the BMS starts to extra discharge HV cells during usage...

If battery cells only at +3 degrees they loose 8-10% of its available capacity so keepeing battery warmer helps to get more kWh from it and also better charging speed when we need DC charge it.

OEM diagnostic tablet for my car cost like whole car screenshoot will not give you any usable info i think my car is BYD Atto 3 but i can post diagnostic check result in pdf format. "Also while balancing, voltage delta vs time trace" this will be different for different charging current and most...

I might be wrong but I think that for proper calibration and getting best SOH afterwards calibration done the discharge and charge cycles for that purpose should be performed when battery not colder then 25 degrees Celsius because LFP when its temperature less then 25°C will have higher internal...