Heat Wave Coming - Battery Health Tips to Remember

[SWO]

As most of the US will be baked with a heat wave of 100ºF+ temps in the next few days, it's important to remember a few tips for battery health:

• Set a charge schedule so your car only charges at night (10 PM - 8 AM recommended), do not charge during the heat of the day.
• Keep battery charged between 15-85%, do not charge to 100% unless absolutely necessary. Very high or low charge levels put more stress on the pack in extreme heat.
• Park in the shade as much as possible. I recommend window shades or ceramic tint.
• Consider leaving the vehicle on while you go into a store (take all keys with you and be sure the doors lock). Vehicle will not shift from park without a key present, and will shut off after 30 minutes.
• Plug in as soon as you arrive at your destination so the battery pack can cool itself with shore power if necessary.
• Ventilate your garage in hot weather so the heat can escape rather than building up inside, especially while charging. Charge outside if temps are cooler.
• If you leave at a regular time, set a departure time (different than remote start) so your battery pack can cool before driving.
• Departure time cools the battery pack, unlike remote start which is focused on cabin cooling.
• Drive conservatively, using less regen is advised in hot weather to reduce pack heating (Whisper mode uses less regen).
• Avoid DC fast charging if possible.
• Consider reducing your EVSE charge rate setting to 32A or less to reduce charger heat load if you desire less fan noise or have charging errors.
• Do not set climate temp below 70ºF and use recirculation mode in extreme heat/humidity to reduce cabin cooling demand (leaves more capacity for pack cooling).
• Expect that your Ford Mobile Charger may start to have charging issues (amber light) in the heat due to a poor thermal design, using an aftermarket wall-mounted EVSE is recommended.
• Some features may be unavailable (BlueCruise) and performance may be limited in extreme temps.

High temperatures of greater than 40ºC/104ºF can degrade the lithium battery pack, especially if it is accepting charge (charging or regen). The Mach-E pack is liquid cooled, with an integrated chiller that uses the A/C compressor. Both the cabin and the pack are cooled by the A/C compressor. Plugging in allows the pack to be cooled with shore power when parked, it will not cool itself while the car is parked unplugged (to avoid draining the battery).

If you have poor connections or faulty charging equipment, it will show up in the heat. Charging errors should be investigated. Feel all cords and plugs for hotness after the car has been charging a while. Anything hot enough to burn you is a red flag. Bad connections may be solved by replacing faulty receptacles, plugs, the charging port, J1772 handle, or the EVSE itself depending on the problem.

The Mach-E was designed to handle the Arizona heat (≤122ºF) provided some pack cooling precautions are taken such as plugging in. You will see a warning about plugging in during extreme temps. Keeping the pack cooler will prolong its life. The battery cells prefer a temperature range similar to humans, around 75ºF is optimal.

Avoid charging during peak demand/heat during the day (unless you have solar), 4-7 PM is the worst possible time to charge during a heat wave because that's when the electrical grid is already at its limits with A/C loads. Charging during peak demand puts more stress on the grid and costs the most money. It's important to understand that electricity used during a peak time may cost your utility 100x more than the normal rate. Therefore it's important that everyone with an EV tries to charge at night when power is cheap and abundant, otherwise the costs will be passed on to us in the form of rate hikes. This applies even if you have a fixed kWh rate all day long, your fixed rate will increase if too many people in your city charge their EVs at the wrong times regardless of rate structure. Overloading and overheating your neighborhood transformer may also be a concern charging at a peak time. Allowing the pack to rest for several hours after driving and charging when the temps are cooler outside is better for the pack as well.

Other tips/tricks are welcome.

This is all fine (maybe a little OCD, but I'm guilty of that too). The 95+% of other EV drivers (like my wife and father in law) who just plug in when the battery gets low and don't worry about anything else will also be fine and probably have similar battery degredation.

I do worry that someone thinking about EVs could read your post and be scared away thinking "I don't have time for all that nonsense." Telling people they shouldn't set the AC below 70 in the summer or should charge at night, for example.

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[macchiaz-o]

Can you please elaborate on the 5th bullet (Plug in as soon as you arrive at your destination so the battery pack can cool itself with shore power if necessary.)? Reason I ask is that there was another thread discussing that it is better to let it cool down after a drive before charging. So are you saying, plug in right away but don’t start charging? Thanks!

See this post:

https://www.macheforum.com/site/thr...ery-health-tips-to-remember.18623/post-440460

 

[macchiaz-o]

This is all fine (maybe a little OCD, but I'm guilty of that too). The 95+% of other EV drivers (like my wife and father in law) who just plug in when the battery gets low and don't worry about anything else will also be fine and probably have similary battery degredation.

I do worry that someone thinking about EVs could read your post and be scared away thinking "I don't have time for all that nonsense." Telling people they shouldn't set the AC below 70 in the summer or should charge at night, for example.

I agree ... Some of these tips feel appropriate and reasonable, but not setting the AC to a level that provides human comfort isn't reasonable (in my opinion).

Also, it's not possible to plug in most places where I park. Outside. Without shade... It is what it is. I can't baby the car when it's primary purpose is to get me where I need to be.

 

[mwtechy]

I would also argue that probably most of us would gladly swap out the current battery with a new one in around a decade given the expected advancements in batteries between now and then. Who knows we might even get nuclear diamond batteries to work by then and you'll never charge the car again lol.

 

[ARK]

While I’d agree that most of these tips are sensible, I think this might be a bit much for 100 degree weather.

While not optimal, 100 degree weather also isn’t catastrophic for a lithium ion battery. I wouldn’t worry too much about restricting driving style or going out of the way to plug in at 100 degrees.

I think places where it can soar to 120 degrees, sure. But if it its basically 90s except for a few hours in the afternoon where it touches 100, I think the response can be more mild (don’t overcharge it, don’t gun it repeatedly, plug in if convenient).

 

[macchiaz-o]

I drove around in this, yesterday, and without doing anything special about it...

@SnBGC lives nearby and drives in the same conditions but almost certainly different driving patterns than me... He's seen 140° shown on his display. So the sensor is clearly near portions of the vehicle that get fairly hot... But still, this is just normal summer time stuff here. Cars are built to deal with it.

 

[breeves002]

These are great tips but I think some people are missing the point.

You don't have to do any of this. You can just keep doing what you're doing. The point of these are for maximum prolonging of the HVB and most efficient way to do things. Most of us here won't keep the car long enough to see serious degradation of the HVB. Some of us will.

You can do none of these things or you can do all of these things.

I am in 100% agreement the car should be able to cool the battery when not plugged in if you have that setting toggled - but there's no setting! There should be an option for minimum SoC... or some other smarter way to know when the HVB is too low to continue conditioning the battery without plugging in.

I also wish you could set the charge limit and charge times globally as well as a current limit. Why the hell can I not set that 90% limit to apply to ALL chargers I plug into? Not just after I've plugged into one before. It is so ridiculous. My car is at the dealer now and charged to 100%. Since I had never charged it there before the only way for me to stop the charge at 90% was to watch the app and when it hit 90% hit stop charge. I did that...but then they unplugged it and plugged it back in and it went to 100%. Frustrating.

 

[Mach-Lee]

This is all fine (maybe a little OCD, but I'm guilty of that too). The 95+% of other EV drivers (like my wife and father in law) who just plug in when the battery gets low and don't worry about anything else will also be fine and probably have similar battery degredation.

I do worry that someone thinking about EVs could read your post and be scared away thinking "I don't have time for all that nonsense." Telling people they shouldn't set the AC below 70 in the summer or should charge at night, for example.

That's a common criticism of my posts, I'm someone that appreciates as much information and details as possible rather than making things simple. Even if you only do half the things you'll still be better off. I'm writing this for the 5% that want the details, and maybe some of details will make it to the masses in time as knowledge is spread. They're all optional.

I agree ... Some of these tips feel appropriate and reasonable, but not setting the AC to a level that provides human comfort isn't reasonable (in my opinion).

Also, it's not possible to plug in most places where I park. Outside. Without shade... It is what it is. I can't baby the car when it's primary purpose is to get me where I need to be.

The issue is some people will get in and crank the climate way down into the 60's thinking the car will get colder faster, this can divert a lot of cooling away from the battery when it needs it the most. After they are too cold, then they will increase the temp. Climate should be set and forget, leave the temp at your preferred setting all the time and let the system do what it needs to for optimal efficiency. This is the use case the Mach-E HVAC system logic was designed for, widely changing the set point is going to hurt the efficiency and waste cooling. Most people are comfortable with air conditioning in the 70-78ºF range, hence the recommendation to keep the setting above 70ºF to avoid wasteful use.

Shade is nice but sometimes it's not available, so just park where you can.

While I’d agree that most of these tips are sensible, I think this might be a bit much for 100 degree weather.

While not optimal, 100 degree weather also isn’t catastrophic for a lithium ion battery. I wouldn’t worry too much about restricting driving style or going out of the way to plug in at 100 degrees.

I think places where it can soar to 120 degrees, sure. But if it its basically 90s except for a few hours in the afternoon where it touches 100, I think the response can be more mild (don’t overcharge it, don’t gun it repeatedly, plug in if convenient).

104ºF and above can be harmful for the battery. In those air temps the pavement could be 120+F in the sun, and that heat radiating on the battery pack from below can easily warm it into the range where some capacity reduction occurs. I believe Teslas actively cool the pack when the car is parked if it gets too hot. But the Mach-E does not do this while unplugged so the battery getting too warm while parked is more of a concern.

I drove around in this, yesterday, and without doing anything special about it...

@SnBGC lives nearby and drives in the same conditions but almost certainly different driving patterns than me... He's seen 140° shown on his display. So the sensor is clearly near portions of the vehicle that get fairly hot... But still, this is just normal summer time stuff here. Cars are built to deal with it.

If you got clear bra, a reminder to make sure they cut out the hole around your temp sensor above the grill shutters so air can flow past it. Most installers miss this. After parking in the sun the sensor will get warmer from radiant ground heat. This reading also reflects the potential heat the bottom of the pack may be experiencing. So if you see more than 120ºF on the display at startup, you should probably think about taking extra precautions to make sure the battery is staying cool.

 

[Logal727]

That's a common criticism of my posts, I'm someone that appreciates as much information and details as possible rather than making things simple. Even if you only do half the things you'll still be better off. I'm writing this for the 5% that want the details, and maybe some of details will make it to the masses in time as knowledge is spread. They're all optional.



The issue is some people will get in and crank the climate way down into the 60's thinking the car will get colder faster, this can divert a lot of cooling away from the battery when it needs it the most. After they are too cold, then they will increase the temp. Climate should be set and forget, leave the temp at your preferred setting all the time and let the system do what it needs to for optimal efficiency. This is the use case the Mach-E HVAC system logic was designed for, widely changing the set point is going to hurt the efficiency and waste cooling. Most people are comfortable with air conditioning in the 70-78ºF range, hence the recommendation to keep the setting above 70ºF to avoid wasteful use.

Shade is nice but sometimes it's not available, so just park where you can.



104ºF and above can be harmful for the battery. In those air temps the pavement could be 120+F in the sun, and that heat radiating on the battery pack from below can easily warm it into the range where some capacity reduction occurs. I believe Teslas actively cool the pack when the car is parked if it gets too hot. But the Mach-E does not do this while unplugged so the battery getting too warm while parked is more of a concern.



If you got clear bra, a reminder to make sure they cut out the hole around your temp sensor above the grill shutters so air can flow past it. Most installers miss this. After parking in the sun the sensor will get warmer from radiant ground heat. This reading also reflects the potential heat the bottom of the pack may be experiencing. So if you see more than 120ºF on the display at startup, you should probably think about taking extra precautions to make sure the battery is staying cool.

I was gonna say, this car is so good at getting cold, I rarely have it set below 74 in Florida.

 

[Mach-Lee]

I was gonna say, this car is so good at getting cold, I rarely have it set below 74 in Florida.

Same, 74ºF is as low as I go in hot weather, so A/C set less than 70ºF would be downright freezing IMO.

 

[SnBGC]

My wife keeps turning the climate to Lo when she takes the car and then leaves it there. Drives me crazy. I tell her to leave it in Auto 3 and it will do just fine but she doesn't take my advice.

 

[SnBGC]

Same, 74ºF is as low as I go in hot weather, so A/C set less than 70ºF would be downright freezing IMO.

Same as you guys. 74F setting is perfect for me, even when it is 115F out.

 

[ZuleMME]

My wife keeps turning the climate to Lo when she takes the car and then leaves it there. Drives me crazy. I tell her to leave it in Auto 3 and it will do just fine but she doesn't take my advice.

My wife will do the opposite version of that, in the winter she just sets the heat at HIGH, automatic temperature control be damned. Heaven forbid it doesn’t blow at 100% out the mid level vents.

 

[Logal727]

My wife keeps turning the climate to Lo when she takes the car and then leaves it there. Drives me crazy. I tell her to leave it in Auto 3 and it will do just fine but she doesn't take my advice.

Yeah my wife will turn the fans to 100, I’m like let the car do it’s thing! I don’t think I’ve ever used Max AC button either.

 

[macchiaz-o]

You don't have to do any of this. You can just keep doing what you're doing. The point of these are for maximum prolonging of the HVB and most efficient way to do things. Most of us here won't keep the car long enough to see serious degradation of the HVB. Some of us will.

That's a common criticism of my posts, I'm someone that appreciates as much information and details as possible rather than making things simple. Even if you only do half the things you'll still be better off. I'm writing this for the 5% that want the details, and maybe some of details will make it to the masses in time as knowledge is spread. They're all optional.

Duly noted. I misunderstood the intent and as a result, my responses are overly harsh -- my apologies.

Climate should be set and forget, leave the temp at your preferred setting all the time and let the system do what it needs to for optimal efficiency. This is the use case the Mach-E HVAC system logic was designed for, widely changing the set point is going to hurt the efficiency and waste cooling. Most people are comfortable with air conditioning in the 70-78ºF range, hence the recommendation to keep the setting above 70ºF to avoid wasteful use.

Same as you guys. 74F setting is perfect for me, even when it is 115F out.

I guess mine doesn't work properly. During daytime driving, if I put the set temperature at 77 degrees F, where I think I'd be adequately comfortable (*), it lowers the fan speed so much that it'll never come anywhere close to reaching that temperature during my drive, even for a 30+ minute drive. At this time of year, I also ensure the cold air is blowing directly at my face.

So I set it lower and lower in order to make the fan speed increase. Mind you, this is on Auto-3 -- I would have thought Auto-3 would already maximize fan speed when it's way over 100F inside the cabin, but on my vehicle, it does not. On SYNC 4A, it's much easier for me to lower or raise the set temp than to override fan speed.

For some reason when it's fully night time, then the set temperature works as I'd expect... It gets properly cool and quite fast. But in daytime, it's not increasing fan speed enough unless I set the temp way below where I want it.

My 2014 Ford Fiesta's automate climate control was easier to use and, with multiple vents aimed at my face, it worked significantly better during summertime than the 2021 Mach-E's.

(*) It's 80F inside my house.

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