Turtle with no warning and 25km range remaining

[Trevor Jack]

Mickey thanks tremendously for near real time support. It's SOO helpful.

Cap2 (OBDZero) running. Initially 6.8A. After about 2 hours it was 3.2A and now, half an hour later again, 1.7A - cell voltages (max, avg and min) all near 4.10v. SoC shown in app is 55% (Cap: 26Ah) - vehicle battery charge indicator is also about there (8 of 16 bars). I took a screen shot - unfortunately that seems to have terminated the session.

Are currents on Cap 2 screen at 360v DC (not the 240v AC)? Charge added might be about 2 * 6.8Ah + about 3Ah = 16.6 Ah ~ 5.1kWh.

 

[MickeyS70]

Cap2 (OBDZero) running. Initially 6.8A. After about 2 hours it was 3.2A and now, half an hour later again, 1.7A - cell voltages (max, avg and min) all near 4.10v. SoC shown in app is 55% (Cap: 26Ah) - vehicle battery charge indicator is also about there (8 of 16 bars). I took a screen shot - unfortunately that seems to have terminated the session.

Yes, any interaction with the phone during CAP2 will terminate the session, unfortunately

Are currents on Cap 2 screen at 360v DC (not the 240v AC)? Charge added might be about 2 * 6.8Ah + about 3Ah = 16.6 Ah ~ 5.1kWh.

Yes, current displayed is measured by the DC sensor inside the HV battery pack.

It all points to the BMU ‘thinking’ that there is a lot more in then tank, than actually is.

The tortoise you experienced is therefore caused by the low voltage protection circuit that prevent the cells going into the ‘red’

With HobDrive out of the picture, you will have to look at a laptop based solution (e.g. MUT3-SE/openport clone) to instantly correct the mismatch.

You can of course let the BMU take care of this automatically, but at a max rate of around 2Ah per month this may take a while..

 

[Trevor Jack]

Charging rate got very low so I stopped charging. OBDZero reported 5.2kWh of 9.1kWh "Fully charged battery capacity". This is consistent with both the vehicle display and my estimate (quite approximate) from observed point in time charging currents and times. I disconnected then reconnected the 12v battery. OBDZero then reported 9.0kWh present charge - the vehicle display showed all 16 bars (8, or possibly 9? before disconnecting the 12v battery).

Seems that capacity is probably close to 5kW with range somewhat less than 40km. I'd be very pleased (and surprised) to hear a different conclusion. 40km range will be very difficult to use. But I'll look into MUT3 to at least improve the data.

Fortunately there is a great retirement plan. We have buddies who live on an island with a maximum round trip distance of 8km who would make excellent use of the vehicle.

 

[MickeyS70]

Charging rate got very low so I stopped charging. OBDZero reported 5.2kWh of 9.1kWh "Fully charged battery capacity". This is consistent with both the vehicle display and my estimate (quite approximate) from observed point in time charging currents and times. I disconnected then reconnected the 12v battery. OBDZero then reported 9.0kWh present charge - the vehicle display showed all 16 bars (8, or possibly 9? before disconnecting the 12v battery).

Yes, that makes sense, unfortunately. The battery has an actual capacity of around 5kWh, but the BMU is set to 9kWh.

When you reconnect the 12V aux, the BMU calculates SoC based on battery (cell) voltage (4.1V = 100%) and then uses the wrong SoH multiplier, resulting in a 9kWh capacity.

But I'll look into MUT3 to at least improve the data.

It will only set the capacity to 5kWh, i.e the RR and fuel gauge will be (more) accurate, but that’s about it.

BTW the guy with the MUT could easily do that for you by changing the ‘battery age’ until the capacity shows about 16Ah.

We have buddies who live on an island with a maximum round trip distance of 8km who would make excellent use of the vehicle.

Great idea