Battery thermal management?

[voxel]

As mentioned before, a cheap obd2 adapter will show you this information on a smartphone.

How accurate is that monitor because I never saw a single temperature change even when the car was pushing out 630As and 250+ kW. It was always 33C

As for leaving the Mach-E at an airport, I've never heard of any EVs except Teslas with vampire drain (up to 1% a day). A car like the ID.4 has been shown to lose only 1% when parked un-plugged for 14+ days.

Sponsored

 

[Rt1AWD]

How accurate is that monitor because I never saw a single temperature change even when the car was pushing out 630As and 250+ kW. It was always 33C

As for leaving the Mach-E at an airport, I've never heard of any EVs except Teslas with vampire drain (up to 1% a day). A car like the ID.4 has been shown to lose only 1% when parked un-plugged for 14+ days.

If the there is a heatwave then it would make sense for the car to do some cooling to the battery....... That drains the battery

 

[voxel]

If the there is a heatwave then it would make sense for the car to do some cooling to the battery....... That drains the battery

If it car + battery just sits in extreme temperature(within reason... like 40C and say -30C), these li-ion batteries aren't going to explode/rot/disintegrate. They aren't that sensitive to temperature when not in use. When in use they NEED to be in an optimal range - thus pre-conditioning (to be cooled or heated) is required.

 

[Rt1AWD]

If it car + battery just sits in extreme temperature(within reason... like 40C and say -30C), these li-ion batteries aren't going to explode/rot/disintegrate. They aren't that sensitive to temperature when not in use. When in use they NEED to be in an optimal range - thus pre-conditioning (to be cooled or heated) is required.

Ok, let's say heating up the battery to 125 or freezing it to 0 or below when it is not in use doesn't affect the battery in any way (is that what you are trying to say?), in this case when you start the car it needs to pre-condition it somehow. It needs energy for preconditioning, however it obviously can't use its own energy.....

 

[JimmyMachE]

How accurate is that monitor because I never saw a single temperature change even when the car was pushing out 630As and 250+ kW. It was always 33C

Short acceleration bursts will heat up the motor coils but not the battery, as battery pack has large thermal inertia. Battery pack will heat up during DC charging and at highway speed:

 

[phidauex]

How accurate is that monitor because I never saw a single temperature change even when the car was pushing out 630As and 250+ kW. It was always 33C

As for leaving the Mach-E at an airport, I've never heard of any EVs except Teslas with vampire drain (up to 1% a day). A car like the ID.4 has been shown to lose only 1% when parked un-plugged for 14+ days.

I told you the battery cooling was good - you have to drive for a long time to see realistic changes in the battery temperature. Even driving for an hour or more I'll usually only see it go up by 1 to 3C.

If you want a little more granularity then you'll want to watch the HVB Temperature Range Maximum and Minimum points, they'll show what the max and min temps, which will be more responsive to change than the average temperature. I don't think I've seen more than 2C temperature variation in the pack, though I haven't watched those points during more aggressive driving.

 

[SnBGC]

If the there is a heatwave then it would make sense for the car to do some cooling to the battery....... That drains the battery

The car doesn't cool the battery when parked off plug. Even in a heat wave. It just sits there absorbing heat. If hot enough and parked for long enough with exposure then the car will divert more energy to cool the battery when the vehicle is eventually started. You might experience limited drive modes until the battery is cooled down. Usually happens fairly quick but sometimes it can take a while.

 

[voxel]

I told you the battery cooling was good - you have to drive for a long time to see realistic changes in the battery temperature. Even driving for an hour or more I'll usually only see it go up by 1 to 3C.

If you want a little more granularity then you'll want to watch the HVB Temperature Range Maximum and Minimum points, they'll show what the max and min temps, which will be more responsive to change than the average temperature. I don't think I've seen more than 2C temperature variation in the pack, though I haven't watched those points during more aggressive driving.

I'm only a little suspicious of it ("trust but verify") because it's drawing 2.5C and massively dropping voltage (nearly 40V or about 10%) and thus should be generating some heat. It is a short burst so maybe the heat is short-lived OR the cooling is incredible and chilling the battery packs. Dunno.

Bjorn's Ioniq 5 video shows very little voltage drop in comparison (5%) when hammering the accelerator (around 3C/250 kW output with a smaller 77 kWh pack) so we can infer the quality of the packs are excellent (maybe even best in industry - very low battery IR) however that car he tested had thermaling issues and temps went to 40 Celsius (albeit he shows that mostly after charging). Without more info, I can't tell if that car has a terrible battery cooling system or the Mach-E has an excellent one.

 

[phidauex]

I'm only a little suspicious of it ("trust but verify") because it's drawing 2.5C and massively dropping voltage (nearly 40V or about 10%) and thus should be generating some heat. It is a short burst so maybe the heat is short-lived OR the cooling is incredible and chilling the battery packs. Dunno.

Bjorn's Ioniq 5 video shows very little voltage drop in comparison (5%) when hammering the accelerator (around 3C/250 kW output with a smaller 77 kWh pack) so we can infer the quality of the packs are excellent (maybe even best in industry - very low battery IR) however that car he tested had thermaling issues and temps went to 40 Celsius (albeit he shows that mostly after charging). Without more info, I can't tell if that car has a terrible battery cooling system or the Mach-E has an excellent one.

The big battery really spreads the heat out - it takes large batteries a long time to heat up. From the Ioniq numbers you gave (I didn't watch the whole video) a 5% voltage drop on a 380V battery (guessing the SOC) would be 19V of drop while drawing 657A, for an internal resistance of 28 mOhms. That would be a very good value, but plausible, with the MachE ER at 35 mOhms.

I do plan on taking more hard runs on my Premium with all the thermal measurements running (and keep trying to talk some GTPE owners into the same), but just haven't had the time (and it isn't easy to find a safe spot to go fast these days). However, from my several hour datalogs and extended regen sessions I don't have any reason to believe that the MachE cooling isn't working well. I'm not stanning and staying it is the best of all worlds or anything, but I design large scale battery systems for a living and I'm happy with how the MachE has been maintaining battery temp. If anything, the front motor seems to be the least cooled component in the drivetrain.

I think the talk about the "battery overheating" is way overdone - the battery is NOT showing overheating signs, or big differential heating which would be a clear sign of insufficient cooling. Ford is indeed being very conservative about their setpoints, but that says more about their risk tolerance than it does about the battery right now.

 

[phidauex]

Update - sorry for fouling your thread, OP, you were warned that battery geeks were here.

My practical advice is the same as others - don't worry too much about it. Set your charge schedule to start later in the evening so your car has a little time to cool down before charging, and if it is just wicked crazy hot out then maybe wait until later to charge. In the winter plug it in whenever practical, and don't worry too much about it when it isn't practical.

It is good to know what the battery likes (moderate temps, moderate charging speeds, mid-range SOCs), but you don't have to rearrange your life around it.

If you DO want to dig into the details because you enjoy it, then I recommend the Viecar Bluetooth 4 ODBII adapter (~$25) and CarScanner Pro (~$5) for iOS or Android. Low cost, convenient, and easy to use for reading a lot of values from the car.

 

[Rt1AWD]

What about using Mach E in extreme temperatures. I'm talking about !!5-!25..... It doesn't happen very often, but it does happen sometimes in SoCal, Arizona, and even up north lately.........

 

[macchiaz-o]

What about using Mach E in extreme temperatures. I'm talking about !!5-!25..... It doesn't happen very often, but it does happen sometimes in SoCal, Arizona, and even up north lately.........

Greg provided a nice explanation on how this works, a little bit earlier on this page:

https://www.macheforum.com/site/threads/battery-thermal-management.10813/post-270593

 

[voxel]

Warning: More battery nerd talk.

The big battery really spreads the heat out - it takes large batteries a long time to heat up. From the Ioniq numbers you gave (I didn't watch the whole video) a 5% voltage drop on a 380V battery (guessing the SOC) would be 19V of drop while drawing 657A, for an internal resistance of 28 mOhms. That would be a very good value, but plausible, with the MachE ER at 35 mOhms.

Minor correction. Ioniq 5 is a 800V system.

30V drop (734v to 704v) after pushing 345.6As to reach 90-100 km/h (around 60mph). See images I snagged from the YouTube video. Of this is an ideal state because of the SoC over 90% and the temps are in the ideal range for a lithium battery (26-30C)



From what I've seen from Bjorn's spreadsheets the Ioniq 5 is the fastest EV from 0 to 100 km/h beating the Model 3 and Mach-E. For a "family sedan" it's going to wipe the floor in terms of raw acceleration.

 

[voxel]

Short acceleration bursts will heat up the motor coils but not the battery, as battery pack has large thermal inertia. Battery pack will heat up during DC charging and at highway speed:

Finally watched the video. His comments at 5:19 and 7:30 are a bit disturbing. In his drive, the battery pack temps did not drop more than 1 degree in 20mins of driving after charging.

I don’t know what to make of the Mach-E since it generates a crapload of power (approx 250kW with 638A) which a tad more than the Ioniq 5 in the same acceleration tests but is 0.8th a second slower to 100km/h and the Mach-E is barely any faster than the steel boat that is the ID.4 AWD (GTX in Europe). See charts. It just might need a diet.

https://insideevs.com/news/527811/hyundai-ioniq5-bjorn-acceleration-tests

Sponsored