Bought a 2017 Bolt EV

[redpoint5]

The Bolt will target something like 70 degrees for the battery while charging, so if it has to burn some electricity to warm it up, it will.

[JSH]

Originally Posted by Piotrsko

Any possibility you have PIDS for battery temps? I am curious about the charge rate below 40f since I know it gets reduced below 60 by my chemistry.

There are something like 35 different PIDs for battery temp.

I'm charging on the Level 2 at work right now.

Air Temp - 46.4F
Battery Coolant Temp - 80.6F
Battery Temp - Avg - 55.4F

So right now as I charge the car is heating the battery coolant and circulating it through the battery attempting to raise the module temperatures.

I can't get a good idea on charge current right now because I'm above 70% SOC and the rate is tapering but I can look at that in the future if our ambient temperates drop below 40F again.

[Piotrsko]

If your pack is anything like my pack, every module has two thermocouples every couple sets of cells, and a couple in the cooling string at exit and entrance. Not suprised they report that many PID since you have that many Bms modules.

you don't charge until you get to 70 degrees so my question is moot.

It also looks like they are using poorer quality cells since your voltage differences are what mine are when it's time to replace

[JSH]

Originally Posted by Piotrsko

If your pack is anything like my pack, every module has two thermocouples every couple sets of cells, and a couple in the cooling string at exit and entrance. Not suprised they report that many PID since you have that many Bms modules.

There are PIDs for every module, average, min, max, ALT average, ALT min, ALT max. These are duplicated (C or F)

Originally Posted by Piotrsko

you don't charge until you get to 70 degrees so my question is moot.

100% of my charging so far has been below 70 degrees. You asked for data charging below 40F. There are no temperatures below 40F in the 10 day forecast.

Originally Posted by Piotrsko

It also looks like they are using poorer quality cells since your voltage differences are what mine are when it's time to replace

I haven't measured cell voltage yet.

[Piotrsko]

Originally Posted by JSH

100% of my charging so far has been below 70 degrees. You asked for data charging below 40F. There are no temperatures below 40F in the 10 day forecast.

You're system is configured such that heaters come on below 70 degrees which did answer one implied question, but not whether your cells would actually charge at colder temps. The Volt pack I have will charge down to 32 but the process elongates horribly from 4 hours to 12

[JSH]

Yesterday the dealership called and said my battery has arrived and I needed to schedule an appointment today or tomorrow. So today at 8 I'm getting a new battery. They say the car will be ready by 5 pm. That is MUCH faster than the 5-6 weeks they said it would take to get the battery - more like 5-6 days.

With this in mind I decided to do a last battery experiment and take my battery down to 0% SOC. I drove to less than 5% SOC and then parked in the driveway and turned the heat and A/C to max. Some early observations

A. The electric resistance heater maxes out at 7500 watts on high and the A/C adds about another 1500 watts.
B. At 5% the last orange bar on the SOC gauge blinks
C. At about 3% the last bar disappears
D. At 0% SOC (0.376%) the RAW number was 5% higher so it looks like GM has a 5% buffer at the bottom.
E. At 0% SOC (5% RAW) my cell voltages were at at 3.2V +/- a bit. I haven't compiled the data from each and done an average or min / max yet

The MyChevy app doesn't work to pull data when a OBDII dongle is installed so I don't have range estimates at low SOC.


Some charging data for Piotrsko.
The Bolt does not slow charging - at least not at temperatures in the 40s.

When I plugged in the Level 2 charger at 0% SOC and 49 degrees it jumped right to 5.78 kW charge rate which is the max for my charge (limited by home wiring not the charger) I charged for a couple hours and then turned it off. This morning at 27% SOC / 43F it jumped right back to charging at 5.78 kW.

[Piotrsko]

Thanks for the experiment. Any idea what the battery temps were while charging? Interesting that it will let you drive the SOC to "0" with the hvac

At those SOC, the battery should absorb every amp you can give it

Other than the obscene quantity of attaching hardware, should only take an hour of labor to swap the pack. Please report the level of charge when they gave it back to you

[JSH]

Originally Posted by Piotrsko

Thanks for the experiment. Any idea what the battery temps were while charging? Interesting that it will let you drive the SOC to "0" with the hvac

Last night the battery temperature was 60.8F. This morning I would expect them to be at ambient as the charger was turn off but I didn't connect and check.

Originally Posted by Piotrsko

Other than the obscene quantity of attaching hardware, should only take an hour of labor to swap the pack. Please report the level of charge when they gave it back to you

Book time is 4.5 hours to 5.5 hours. I dropped off the car at 8:15 am and they called at 11:45 am to say it was done. They charged it on their DC fast charger to 100%

The guess-o-meter is ALL over the place. Started at 200 mile range and then dropped to 135 after driving 25 miles. Average mi / kWh dropped from 4 to 1 and then has been slowly increasing since. The Service Rep said it would take 2-3 full discharge / charge cycles to learn the new capacity.

It is most definitely a new battery pack. The old pack had a flat bottom from sill to sill. The new one isn't so fancy.




When I dropped off the car they had 17 batteries stacked up. When I picked up the car they had 22 batteries. Service Rep said they replace 4 batteries a day

[redpoint5]

Personally I'd have waited another 5 years, then got the new pack.

Jason's in the business and probably more sensitive to those jerk moves.

[JSH]

Originally Posted by redpoint5

Personally I'd have waited another 5 years, then got the new pack.

Jason's in the business and probably more sensitive to those jerk moves.

If I planned to have this car in 5 years I would have seriously considered it. Since I don't plan on keeping the car long term I didn't see any reason to delay getting the new pack with more range.