People with Evbatmon or Phev watchdog or other please help.

[Trex]

Hi,

As part of my research into the drive battery I need some measurements taken.

Can you provide voltages of the cell in your PHEV when the drive battery is empty.

Now the voltage will "drift" under varying loads so we need a common load on the drive battery and I suggest reading while stopped and place the transmission into Park and no heating and A/C.

There will be still be a small load placed on the battery as most will know but it puts us at a fairly common ground for measuring IMO.

I would especially like some brand new car owner's measurements but all will be taken into consideration. So please give age of PHEV and kms or miles driven.

Now on the apps there will be a max and min cell voltage so provide both if you can. Eg 3.? Max 3.? Min. The apps are very close in their readings from what I have seen last weekend.

My PHEV has been taken on a trip to Sydney by my sons but should be home early next week by the latest so should be able to show my PHEV soon.

If anyone has a better way to compare please let us know. If we measure reasonable quickly when stopped the voltage should be reasonable accurate to compare.

Ok we will need to know the SOC I think as well to allow for the slower speed drift down of the SOC. Ie at higher speeds my PHEV starts the petrol motor around 30% SOC from memory but at slower speeds I think it may go as low as 26 or 27%.

So need SOC, battery cell volt Max and Min, and age and mileage please and App used Evbatmon or Phev watchdog. If the petrol motor starts to run (to charge) wait for it to stop please.

Regards Trex.

 

[HHL]

Hi,

As part of my research into the drive battery I need some measurements taken.

Can you provide voltages of the cell in your PHEV when the drive battery is empty.

Now the voltage will "drift" under varying loads so we need a common load on the drive battery and I suggest reading while stopped and place the transmission into Park and no heating and A/C.

There will be still be a small load placed on the battery as most will know but it puts us at a fairly common ground for measuring IMO.

I would especially like some brand new car owner's measurements but all will be taken into consideration. So please give age of PHEV and kms or miles driven.

Now on the apps there will be a max and min cell voltage so provide both if you can. Eg 3.? Max 3.? Min. The apps are very close in their readings from what I have seen last weekend.

My PHEV has been taken on a trip to Sydney by my sons but should be home early next week by the latest so should be able to show my PHEV soon.

If anyone has a better way to compare please let us know. If we measure reasonable quickly when stopped the voltage should be reasonable accurate to compare.

Ok we will need to know the SOC I think as well to allow for the slower speed drift down of the SOC. Ie at higher speeds my PHEV starts the petrol motor around 30% SOC from memory but at slower speeds I think it may go as low as 26 or 27%.

So need SOC, battery cell volt Max and Min, and age and mileage please and App used Evbatmon or Phev watchdog. If the petrol motor starts to run (to charge) wait for it to stop please.

Regards Trex.

I did this a little while ago:

Capacity SOC Cell voltage
90.53 33 3.84
91.58 31 3.84
90 29.5 3.83
90 28 3.83
89.47 27 3.8
88.95 27 3.81
90 26.5 3.82
89.47 26 3.81
88.16 26 3.81
88.42 23.5 3.79

I think the capacity estimate is a little pessimistic based on the cell voltage, but of course I don't know what exactly it should be for the chemistry in that battery.
Also note that it went down to 23.5% once, I think that time the engine just started as I pulled into my garage. I didn't think the ECU would normally let it go that low.

 

[Trex]

I did this a little while ago:

Capacity SOC Cell voltage
90.53 33 3.84
91.58 31 3.84
90 29.5 3.83
90 28 3.83
89.47 27 3.8
88.95 27 3.81
90 26.5 3.82
89.47 26 3.81
88.16 26 3.81
88.42 23.5 3.79

I think the capacity estimate is a little pessimistic based on the cell voltage, but of course I don't know what exactly it should be for the chemistry in that battery.
Also note that it went down to 23.5% once, I think that time the engine just started as I pulled into my garage. I didn't think the ECU would normally let it go that low.

Well done HHL,

Showing capacity is a good idea I think.

Wow 23.5%. :shock:

Regards Trex.

 

[HHL]

Hi Trex,

I think it would be more useful if the actual cell resistance could be read from the BMU. In my experience with batteries, a small increase in cell resistance does not necessarily indicate capacity loss. In the case of the PHEV, an increase in cell impedance of as little as 1mOhm means an extra 200mV voltage sag at maximum load. This could trigger an engine start earlier, if that is the main criteria for entering serial hybrid mode. As the BMU would keep track of when this happens, i.e. how much energy has been delivered, over time it would slowly reduce the available capacity estimate. So, while I think the reduced SOH indicates something, it may not reflect the true battery capacity.

 

[Trex]

Hi Trex,

I think it would be more useful if the actual cell resistance could be read from the BMU. In my experience with batteries, a small increase in cell resistance does not necessarily indicate capacity loss. In the case of the PHEV, an increase in cell impedance of as little as 1mOhm means an extra 200mV voltage sag at maximum load. This could trigger an engine start earlier, if that is the main criteria for entering serial hybrid mode. As the BMU would keep track of when this happens, i.e. how much energy has been delivered, over time it would slowly reduce the available capacity estimate. So, while I think the reduced SOH indicates something, it may not reflect the true battery capacity.

Hi HHL,

Totally agree about it I think it is not representing a true battery capacity.

But I do not want to comment too much yet until I have done some further research.

On the BMU data list No 16 and 17 from the MUT -III it shows Max and Min Internal resistance in mohm and from memory Evbatmon can show that as a PID that can be brought in.

Regards Trex.

 

[anko]

Turn off electric seat heating. Even though it is 12 volt, the effect is actually visible in the charge current for the main battery :idea:

 

[generaltso]

Turn off electric seat heating. Even though it is 12 volt, the effect is actually visible in the charge current for the main battery :idea:

Why is that? I suppose the same would be true with any 12 volt draw like rear defrost, heated steering wheel, or headlights?

 

[anko]

I can only imagine, the DC/DC converter that recharges the aux battery from the HV battery is active all the time (at least as long as the car is in Ready mode) and rather than recharging the 12 volt battery when it goers low, it directly sources the 12v volt system of the car.

For sure, should be the same for lighting and heated steering wheel (which I don't have). But I never looked at these. I did, however, play with the heated seats while waiting for a traffic light, and my OBD tools could see the difference between 0, 1 or 2 seats active.

 

[HHL]

I can only imagine, the DC/DC converter that recharges the aux battery from the HV battery is active all the time (at least as long as the car is in Ready mode) and rather than recharging the 12 volt battery when it goers low, it directly sources the 12v volt system of the car.

For sure, should be the same for lighting and heated steering wheel (which I don't have). But I never looked at these. I did, however, play with the heated seats while waiting for a traffic light, and my OBD tools could see the difference between 0, 1 or 2 seats active.

The power supply for the 12V system is obviously on all the time the car is in ready mode. It supplies about 14V to keep the aux battery charged and any load on the 12V system would certainly show up, I would imagine a heated seat would be about 100W, at least initially.
I did find the PID for battery resistance in EVBATMON yesterday, mine shows 1.5 mOhm min and max, I wonder if how much difference there is in cars with higher battery degradation.

 

[anko]

I would imagine a heated seat would be about 100W, at least initially.

Haha, not bad. From my tests, I came to the conclusion that it was about 70 watts (in high setting).

 

[ScottyDont]

Here's some data from today.

Range was down to dashes and the car sat for about an hour before I could measure it.

2014 base model, 37,245km and 3.98L/100km total since new.

EvBatMon data

Capacity 33.2Ah, 87.37%
SoC 9.5Ah, 28.5%
Voltage 306V
Cell Voltage Min 3.82V Max 3.83V
Temps Max and Min 32deg C
IR Max and Min 1.5mOhm
Power output in Ready no aircon - 0.31kW

 

[Trex]

Here's some data from today.

Range was down to dashes and the car sat for about an hour before I could measure it.

2014 base model, 37,245km and 3.98L/100km total since new.

EvBatMon data

Capacity 33.2Ah, 87.37%
SoC 9.5Ah, 28.5%
Voltage 306V
Cell Voltage Min 3.82V Max 3.83V
Temps Max and Min 32deg C
IR Max and Min 1.5mOhm
Power output in Ready no aircon - 0.31kW

Thank you ScottyDont ,

This is probably everything we need to compare it properly.

Regards Trex.

 

[AndyH]

Moar datas!

2018 US model with 2050 miles/3370 km on the odometer.

PHEV Watchdog V0.8xxx

100% battery health; 38.0 Ah

29.5% SOC
1 bar on battery gauge

3.817V for the lowest
3.823V average

51°C coolest cell
54°C average pack temp

 

[Trex]

Moar datas!

2018 US model with 2050 miles/3370 km on the odometer.

PHEV Watchdog V0.8xxx

100% battery health; 38.0 Ah

29.5% SOC
1 bar on battery gauge

3.817V for the lowest
3.823V average

51°C coolest cell
54°C average pack temp

AndyH thanks.

A new PHEV's data.

Your battery is running hot.

 

[AndyH]

Moar datas!

2018 US model with 2050 miles/3370 km on the odometer.

PHEV Watchdog V0.8xxx

100% battery health; 38.0 Ah

29.5% SOC
1 bar on battery gauge

3.817V for the lowest
3.823V average

51°C coolest cell
54°C average pack temp

AndyH thanks.

A new PHEV's data.

Your battery is running hot.

Yessir - and it's technically 'winter' in San Antonio (that was an 80°F/27°C day...yay?). Wait until it actually gets hot outside. :lol:

 

[AndyH]

FWIW, here's a new battery with a full charge. Also..some idea of what it takes to cool a battery.

I did my grocery run in EV mode yesterday and plugged the car in for a full charge about 1:30pm. The car had only been driven 6 or so miles/9.8 km. Outside temperature was 77°F/25°C.

Watchdog after the car had been parked for about 6 hours:

99.7% capacity 37.9 Ah
99.2% SOC
327.6 VDC
Min 43°C Max 44°C
Min 4.093 V Max 4.096 V

A cold front passed overnight and it's been raining for about 12 hours. Outside temp is 49°F/9°C The car's been sitting for about 18 hours.

99.7% capacity 37.9 Ah
98.7% SOC (though Watchdog reported a loss of only 0.1 Ah)

Min 36°C Max 39°C
Min 4.092 V max 4.095 V

The battery does hold on to the heat. I wonder if it heats up in a cold climate as slowly as it cools down? I'm going to have to figure out how to force the battery to cool, I think, because the car didn't run the AC when the battery temp was 45°C.



ETA... Took a drive and the battery's discharged.

3PM 42°F/5.5°C
99.7% capacity 37.9 Ah
29.6% SOC

Min 35°C Max 39°C
Min 3.807 Max 3.813

304.8 VDC

I'll let it sit for a few hours and check the numbers again.

9PM 45°F / 7°C
No voltage change 'notice' from the Dog

99.7% capacity 37.9 Ah
29.3% SOC 11.1 Ah

Min 30°C Max 33°C
Min 3.775 Max 3.781

302.5 VDC

 

[Trex]

The battery does hold on to the heat. I wonder if it heats up in a cold climate as slowly as it cools down?

Do you mean the battery case has good thermal insulation?

I'm going to have to figure out how to force the battery to cool, I think, because the car didn't run the AC when the battery temp was 45°C.

Ok, if the PHEV Watchdog is reading those temps correctly I would be starting to worry. I have not seen those temps on my PHEV. Highest I have seen are around 36C from memory on the battery on a 42C (Got to 47C in Penrith which is in western Sydney) ambient temp day here. The A/C on the case was running and could be seen on the MMCS display when cabin A/C was turned off.

But I would not be surprised if Watchdog was reading those temps incorrectly as you have a new model that has been brought into a different market than ours here.

I will be getting a new model PHEV in about a month and will check mine as well.

 

[Trex]

Here is my data.

Early 2014 build about 62000kms.

Phev Watchdog................................................................Evbatmon

Bat health 77.1% 29.3 Ah................................................77.1% 29.3Ah

SOC 25.9% 7.6 Ah..........................................................25.5%

MinV 3.817 MaxV 3.826..................................................MinV 3.82 MaxV 3.82

BatV total 305.7.............................................................305.6

Internal resistance from MUT-III 1.5 mohm Max and Min.

Will do a full charge reading on my PHEV as well and add it here later. Can others do the same for theirs as well ie full battery readings please. Just like AndyH did.

Regards Trex.

 

[ScottyDont]

Finished charging a short while ago.

EvBatMon data

Capacity 33.2Ah, 87.37%
SoC 32.9Ah, 99%
Voltage 327.6V
Cell Voltage Min 4.09V Max 4.10V
Temps Min 28°C and Min 32°C
IR Max and Min 1.5mOhm
Power output in Ready no aircon - 0.33kW

 

[AndyH]

The battery does hold on to the heat. I wonder if it heats up in a cold climate as slowly as it cools down?

Do you mean the battery case has good thermal insulation?

:lol: I'm still not sure about insulation, but there's definitely some thermal mass.

I'm going to have to figure out how to force the battery to cool, I think, because the car didn't run the AC when the battery temp was 45°C.

Ok, if the PHEV Watchdog is reading those temps correctly I would be starting to worry. I have not seen those temps on my PHEV. Highest I have seen are around 36C from memory on the battery on a 42C (Got to 47C in Penrith which is in western Sydney) ambient temp day here. The A/C on the case was running and could be seen on the MMCS display when cabin A/C was turned off.

But I would not be surprised if Watchdog was reading those temps incorrectly as you have a new model that has been brought into a different market than ours here.

I will be getting a new model PHEV in about a month and will check mine as well.

The car's been sitting almost 24 hours and outside temps only hit 72F/22C. When I started the car to make sure Dog 9.2 worked ok, the battery was 39C. Something's odd, that's for sure. I sat with the AC running, then took a short drive with AC and the battery temp went up 2 degrees.

I look forward to your numbers - congrats on the new ride!