Fast Charging While It's Cold Outside

[SmileyDude]

We're coming into our first winter here with the MME and I'm curious about the effect of cold weather on charging, particularly fast charging in this case. My wife just attempted to use an EA charger while out and never even came close to the theoretical 150kW charging speed. It topped out at 36kW for the entire duration of the charge session. Is this expected? Or did we just get a bad charging station? And before anyone asks -- the heater was turned off while charging. Just the radio was running while attempting to charge.

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[hybrid2bev]

We're coming into our first winter here with the MME and I'm curious about the effect of cold weather on charging, particularly fast charging in this case. My wife just attempted to use an EA charger while out and never even came close to the theoretical 150kW charging speed. It topped out at 36kW for the entire duration of the charge session. Is this expected? Or did we just get a bad charging station? And before anyone asks -- the heater was turned off while charging. Just the radio was running while attempting to charge.

What was the temp outside?

If above 32F then maybe just get a bad charging station.

I've had it max out around 33 kW to 36 kW on both EA and ChargePoint DCFC stations when really cold (15F). I've learned if it's below freezing to yo-yo drive (hard acceleration and full regen) for a bit before arriving at the charger. That seems to allow better charging speeds by warming up the battery.

 

[SmileyDude]

What was the temp outside?

If above 32F then maybe just get a bad charging station.

I've had it max out around 33 kW to 36 kW on both EA and ChargePoint DCFC stations when really cold (15F). I've learned if it's below freezing to yo-yo drive (hard acceleration and full regen) for a bit before arriving at the charger. That seems to allow better charging speeds by warming up the battery.

It was right around 33°F. So not quite freezing, but pretty close.

As far as warming up the battery, I thought I read somewhere that there was a heater in the battery pack for just this sort of thing. Or was that something I imagined instead? ?

 

[hybrid2bev]

It was right around 33°F. So not quite freezing, but pretty close.

As far as warming up the battery, I thought I read somewhere that there was a heater in the battery pack for just this sort of thing. Or was that something I imagined instead? ?

There is a shared coolant loop that will heat the battery and the passenger cabin. Which is why you should turn off the cabin heater for the first 10 minutes (per Ford) to allow all the heat to go to the battery if it's cold.

Being close to freezing temps I would guess it could have been either a thermal issue or just a slow station or a bit of both. ?‍ Since it lasted the whole charging session (assuming you charged for >15 minutes with the cabin heat off) I would lean towards a bad station.

 

[breeves002]

36kW sounds like a bad EA charger unfortunately. I've been able to get 40kW+ off of a 50kW charger at 15ºF before.

 

[Brutakus]

36kW is generally failure mode on an EA charger. If you look on your EA app and find that station, it should show its capped at 50kW but will only give out 36 or less.

EA has been TERRIBLE with station maintenance in my area lately. There's only 3 locations in my whole area and 1 has been out of commission for a month now and before that only 2 chargers worked. The other 2 locations only have 1-2 good chargers at each location with one charger being in failure mode for a month.

 

[06VistaGT]

I did my first fast charge today. EA 350kW charger.

39F when I charged. Car was warm when I pulled up. At 26% charge.

Plug and charge worked perfectly, which was a nice surprise. The charge started slowly but quickly went up to about 65 kW after maybe 30-60 seconds. I then went back into the car, turned it on (for heat) and didn't pay too much attention. Couldn't see the charge speed from inside the car and the in car screen doesn't give hardly any info.

As the battery approached 50% charge, I got out and checked the charge rate. The highest I saw was 78 kW in the 15 seconds I watched.

I ended the charge just shy of 18 minutes. Added 25% of battery, which aligned perfectly with the 22.0kWh listed on the receipt that was emailed to me from Ford.

If my math is correct, I averaged ~73 kW during the charge.

So just about half of peek rate at 39F. And I was in the charging sweetspot of 25%-50%. Compared to above, my experience seemed pretty good. Need to charge in warmer weather to really get a good comparison, though.

 

[ChasingCoral]

We're coming into our first winter here with the MME and I'm curious about the effect of cold weather on charging, particularly fast charging in this case. My wife just attempted to use an EA charger while out and never even came close to the theoretical 150kW charging speed. It topped out at 36kW for the entire duration of the charge session. Is this expected? Or did we just get a bad charging station? And before anyone asks -- the heater was turned off while charging. Just the radio was running while attempting to charge.

If it happens again, move to another chargers at the station. It’s an EA issue.

 

[TruWrecks]

You should have reported it.

It was 36F today where I was charging and it hit 136kWh on an EA 350 kWh station.

 

[noway]

36kW is pretty common in cold weather. The charge limit seems to be at 30kW if battery temperature is below 15C/60F. If adding the 5kW heater to it it will be about 35kW.

The problem is that the 5kW heater seems to operate in only one out of two modes, it can either heat the cabin or it can heat the battery, not both, even if it can physically. If the cabin requires 1kW of heating it will run the heater at 1kW and not run any battery heating. This is why the E-heat MUST be turned off when trying to fast charge with cold battery. It will not try to pre-heat the battery pack so while driving the battery pack can be sitting at close to freezing temperature, and then trying to fast-charge means it will need to heat the battery for a long time before it will get more than 30kW.

There is another limit of about 70kW which it will need a lot higher temperature to go past.

Also looking at the numbers, as far as I can see, if the battery pack sits at <10C it will loose up to 10% of its kWh capacity due to lower voltage. Since it does not try to heat the battery (as this would cause higher consumption) it will rather keep the lower consumption and get lower capacity from the battery (that is less kWh/%). This means that some way of manually triggering battery heating would be really nice to have..

 

[HuntingPudel]

60-ish temps. My first L3 charge plateaued at 46 KW at an EA station, then failed when the car went from 56% to 74%. ?? I figure bad station.

 

[Mach-Lee]

The problem is that the 5kW heater seems to operate in only one out of two modes, it can either heat the cabin or it can heat the battery, not both, even if it can physically. If the cabin requires 1kW of heating it will run the heater at 1kW and not run any battery heating. This is why the E-heat MUST be turned off when trying to fast charge with cold battery. It will not try to pre-heat the battery pack so while driving the battery pack can be sitting at close to freezing temperature, and then trying to fast-charge means it will need to heat the battery for a long time before it will get more than 30kW.

That seems like an issue? The way the plumbing is set up, the battery can only get the warm coolant after it has passed through the heater core, so it should get whatever waste heat is left. If the heater is outputting 5 kW and the cabin only uses 1 kW, then the other 4 kW should go to the pack when the 4-way valve is open. The temp blend doors would control the amount of air flowing through the heater core to control the balance between cabin and battery. Turning the fan speed down should also save more heat for the pack. I find it hard to believe it couldn't try to heat both at the same time? I don't disagree about turning off E-heat to speed DCFC up, but it shouldn't be an all-or-nothing proposition.

 

[Shayne]

36kW is pretty common in cold weather. The charge limit seems to be at 30kW if battery temperature is below 15C/60F. If adding the 5kW heater to it it will be about 35kW.

The problem is that the 5kW heater seems to operate in only one out of two modes, it can either heat the cabin or it can heat the battery, not both, even if it can physically. If the cabin requires 1kW of heating it will run the heater at 1kW and not run any battery heating. This is why the E-heat MUST be turned off when trying to fast charge with cold battery. It will not try to pre-heat the battery pack so while driving the battery pack can be sitting at close to freezing temperature, and then trying to fast-charge means it will need to heat the battery for a long time before it will get more than 30kW.

There is another limit of about 70kW which it will need a lot higher temperature to go past.

Also looking at the numbers, as far as I can see, if the battery pack sits at <10C it will loose up to 10% of its kWh capacity due to lower voltage. Since it does not try to heat the battery (as this would cause higher consumption) it will rather keep the lower consumption and get lower capacity from the battery (that is less kWh/%). This means that some way of manually triggering battery heating would be really nice to have..

Like this Kia EV6. When I watched the vid I thought the computer could switch the hvac off and on when needed and leave the owner out of it. Since we only have 50 KW up here the heat will most likely be on. I may play with it a bit now you indicate this is going on to see the benefits of being uncomfortable.

I see no BMS when it is plugged into a 240V outlet which would be nice to have also. If it is heating up the cabin under remote start guess it will not be doing too much for the batteries at that stage? I think I hear the heater blower as soon as the remote start kicks in. A precondition button would be nice and then a remote start. If it is on shore power it could heat the batteries up before taking off. You would think that may not be happening in the 15 minutes.

 

[noway]

That seems like an issue? The way the plumbing is set up, the battery can only get the warm coolant after it has passed through the heater core, so it should get whatever waste heat is left. If the heater is outputting 5 kW and the cabin only uses 1 kW, then the other 4 kW should go to the pack when the 4-way valve is open. The temp blend doors would control the amount of air flowing through the heater core to control the balance between cabin and battery. Turning the fan speed down should also save more heat for the pack. I find it hard to believe it couldn't try to heat both at the same time? I don't disagree about turning off E-heat to speed DCFC up, but it shouldn't be an all-or-nothing proposition.

Yes and no.. seems to be some software issues here. It can avoid heating the cabin by just not sending air through the heater core (just as an ICE), but the real issue seems to be that it decides to reduce the power to the heater core when the cabin does not need it, rather than running full power and letting the battery use the remaining.

Its just my observations when sitting at chargers with OBD port connected looking at the temperature of the coolant inlet sensor for the HVB and subtracting the battery power flow from the charger power flow.

The turning off E-heat actually is an "official solution". It was mentioned in one of the videos from Bjørn Nylund when testing the Mach-E in winter (https://www.youtube.com/user/bjornnyland) that he had gotten that response from Ford, and that it was supposed to be fixed with a software update later.

 

[DaMeatMan]

We're coming into our first winter here with the MME and I'm curious about the effect of cold weather on charging, particularly fast charging in this case. My wife just attempted to use an EA charger while out and never even came close to the theoretical 150kW charging speed. It topped out at 36kW for the entire duration of the charge session. Is this expected? Or did we just get a bad charging station? And before anyone asks -- the heater was turned off while charging. Just the radio was running while attempting to charge.

Until Ford pushes an update to actually enable battery preconditioning, you are not going to see anything near the rated 150KW changing speeds.

Ideally the customer should be able to MANUALLY turn on battery preconditioning, since many of us use 3rd party navigation through Android Auto or Apple Car Play, which means the built in infotainment system will never know we are navigating to a fast charger like a Tesla would, and would therefore never enable preconditioning if it was only enabled through navigation to a fast charger via the built in maps. So hopefully Ford doesn't do that, and they give is a manual button to start pre-conditioning like you see in the Lucid Air.

I know Ford unofficially hinted that an update to address preconditioning would be coming in Q4 of this year. But with that said, it seems to me like they are behind schedule getting these updates out the door as promised.

This one will be super critical for this Winter, and if they miss the mark you are certainly going to see allot of very grumpy posts on this forum throughout the winter time.

Right now as I understand it heating of the battery for charging will only take place when plugged in, and since we are paying by the minute rates, and the fact that it can take upwards of 30 min or more to heat a cold soaked battery, waiting until you are actually plugged in leads to an absolutely horrible customer experience.

So let's wait and see and hope they are on the ball with this!

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