No charge with cold battery

[artsci]

For the past several days it's been extremely cold here in Maryland, with temps overnight in the teens and in the 20s during the day. My car sat outside for several days with only short drives of less five miles or so. Having not encountered this before I wan't aware of cold weather charging issues. If only I had looked them up on TMC.

For the past two evenings the car wouldn't accept a charge. I worked with Tesla service to determine a fix and nothing seemed to work (resetting the UMC, powering the car off, leaving the climate control running, etc.) I thought the car would need to go into service for a fix.

Today the car was inside all day as the new higher res front and rear cameras were being installed, so the battery pack warmed up. When I got home and plugged in the car it started charging immediately at normal rates.

Lesson learned? When the battery gets too cold it will not charge. If it gets cold enough turning on the climate control is not sufficient to heat it up to charging levels. And one cannot keep the climate controls on long enough to heat the battery to sufficient levels. A conundrum for sure.

What do owners in much colder climes that Maryland do to keep the battery sufficiently warm to charge?

 

[gavine]

There are tons of Teslas in Norway. There must be a solution.

 

[andrewket]

The car should start warming the pack to a temperature that is safe to charge. When this happens the LEDs on the EVSE will show energy is flowing and the car should show the voltage, but 0 amps. If you leave it alone it should eventually start charging.

 

[chillaban]

The car should start warming the pack to a temperature that is safe to charge. When this happens the LEDs on the EVSE will show energy is flowing and the car should show the voltage, but 0 amps. If you leave it alone it should eventually start charging.

This was my experience when I was in Tahoe in around 15 degrees F conditions. Plugging in after being left out in the cold, initially the car seemed to be heating the pack or something, as it was taking in a small amount of power but not making any charging progress.

After maybe 15 minutes it started making progress charging.

 

[wcfinvader]

We never have had any problems charging car and it's gotten down between -20°F & -30°F. It always starts very slow and not charging for 15 minutes like a previous commenter said but will be at full speed of 80 amps within a half hour for us.

 

[artsci]

Mine was plugged in over two night and no charging occurred. That rang alarm bells as nothing seemed to raise the temp of the battery to safe charging levels.

 

[JClu]

Have you tried to plug into a SuperCharger? With my limited experience (1st winter with the S), SC warms up the battery way faster than traditional home charging.

 

[DarkMatter]

Do you have Range Mode on? Are you using scheduled charging? There have been threads recently about both of those things inhibiting charging.

 

[brucet999]

Do you have Range Mode on? Are you using scheduled charging? There have been threads recently about both of those things inhibiting charging.

Seems like "overnight and no charging occurred" would eliminate scheduled charging as the problem, don't you think?

 

[hacer]

Mine was plugged in over two night and no charging occurred. That rang alarm bells as nothing seemed to raise the temp of the battery to safe charging levels.

Was this plugged into 240V, or 120V? It's possible that the low power available from a 120V outlet is insufficient to warm the battery to where it will charge.

 

[DarkMatter]

Seems like "overnight and no charging occurred" would eliminate scheduled charging as the problem, don't you think?

Not necessarily. I can't tell from the original post if the car is set up for a TOU plan or not. Being plugged in overnight is one of the exact use cases for scheduled charging.

 

[randvegeta]

Was this plugged into 240V, or 120V? It's possible that the low power available from a 120V outlet is insufficient to warm the battery to where it will charge.

Even at 220v it may not be enough. I opened a similar thread a few days ago when I plugged in and received no charge overnight. I was plugged into 220v @ 10ams (2.2kw) with temperatures outside at -20c // -4f. Obviously there was not enough power being supplied to heat the battery, let alone heat AND charge.

When plugging into a 32amp outlet, I was able to get 26km/h of charge rather than my usual 35, suggesting around 25% of the 7kw supply was being used by the battery heater. 7kw * 25% = 1.75kw. So when it was super cold, it used a constant 1.75kw just to keep it warm enough to pump 5.25kw of energy into the battery.

In theory, the 2.2kw outlet should have been enough to heat up the battery and charge at the super super slow rate of 0.45kw (2.3km/h). But charging itself actually produces some heat so probably that 0.45kw of 'extra' power going into the battery produced next to no heat, making the 1.75kw insufficient.

Solution? Use a higher power charger!

 

[gavine]

Would it be worth driving the car around for a few miles to warm-up the battery enough to start taking a charge or would you use-up more miles than you can replenish with a low power charging source? I guess it depends on the ambient temperature and how cold-soaked the battery is. It might take 15 miles of driving to warm it up but at 2kW charging, it would take a while to replenish and the battery might still chill faster than the charging can keep it warm enough. I think I may have just answered my own question

 

[wcfinvader]

Would it be worth driving the car around for a few miles to warm-up the battery enough to start taking a charge or would you use-up more miles than you can replenish with a low power charging source? I guess it depends on the ambient temperature and how cold-soaked the battery is. It might take 15 miles of driving to warm it up but at 2kW charging, it would take a while to replenish and the battery might still chill faster than the charging can keep it warm enough. I think I may have just answered my own question

It would take quite a bit of driving to heat it up. We charge for 10-20mins on a HPWC and that still doesn't heat the battery up enough to get rid of the yellow dashed lines. It does heat up enough to get up to 80 amps within that time though.

 

[Rocky_H]

Was this plugged into 240V, or 120V? It's possible that the low power available from a 120V outlet is insufficient to warm the battery to where it will charge.

This does seem like the big question that I haven't seen the OP come back to answer. Low power just can't warm the battery up enough to also spare energy for charging.

In theory, the 2.2kw outlet should have been enough to heat up the battery and charge at the super super slow rate of 0.45kw (2.3km/h). But charging itself actually produces some heat so probably that 0.45kw of 'extra' power going into the battery produced next to no heat, making the 1.75kw insufficient.

Yeah, probably just a little more to it than that. The 1.75kW was keeping it at that temperature once it was already warmed up and charging was running. The battery heater is 6kW, so I would think that to initially warm it up, it was needing to use 4kW+ at least to get it warmed up.

 

[Evbwcaer]

One work-around to this that is only sometimes practical is to plug the car in immediately after driving.

I can't recall the exact conditions, but last winter I plugged into a 110v upon arriving, was parked outside for 2 days, temps were probably down to 0f at night, and got the usual 3.5 mph.

I speculate that if the battery gets too cold, lower charge powers may not have the ability to get over the thermal "inertia."

 

[mknox]

I can't recall the exact conditions, but last winter I plugged into a 110v upon arriving, was parked outside for 2 days, temps were probably down to 0f at night, and got the usual 3.5 mph.

Same here. I had stopped at a hotel on a winter road trip and plugged into a 120 volt outlet as soon as I arrived. My goal was just to try and hold on to the range I had overnight, but in the morning I was pleased to see I had added a bunch of miles (figured I was getting about 3 MPH). Wasn't down to 0 F, but well below freezing in my example.

 

[RDoc]

Same here. I had stopped at a hotel on a winter road trip and plugged into a 120 volt outlet as soon as I arrived. My goal was just to try and hold on to the range I had overnight, but in the morning I was pleased to see I had added a bunch of miles (figured I was getting about 3 MPH). Wasn't down to 0 F, but well below freezing in my example.

That's very good info, thanks.

 

[Missile Toad]

Does anybody have enough experience in the tundra (everything North of Kansas is tundra from a Texan's point of view) to comment on what power was exhausted in maintaining battery warmth -- and thus, can be attributed to 'vampire current' in nights below freezing?

 

[neroden]

Even at 220v it may not be enough. I opened a similar thread a few days ago when I plugged in and received no charge overnight. I was plugged into 220v @ 10ams (2.2kw) with temperatures outside at -20c // -4f. Obviously there was not enough power being supplied to heat the battery, let alone heat AND charge.

Hmmm. I've never used a low-amperage 220 socket. At 220V 70 amps it charges fine at -14F. At 240V 40 amps it still charges fine.

When plugging into a 32amp outlet, I was able to get 26km/h of charge rather than my usual 35, suggesting around 25% of the 7kw supply was being used by the battery heater. 7kw * 25% = 1.75kw. So when it was super cold, it used a constant 1.75kw just to keep it warm enough to pump 5.25kw of energy into the battery.

I think we have the answer here.

In theory, the 2.2kw outlet should have been enough to heat up the battery and charge at the super super slow rate of 0.45kw (2.3km/h). But charging itself actually produces some heat so probably that 0.45kw of 'extra' power going into the battery produced next to no heat, making the 1.75kw insufficient.

Solution? Use a higher power charger!