Charging at <0F ?

[jmueller065]

In our super cold spell #2 (I refuse to use "Polar Vortex" because it isn't: The Polar Vortex is firmly planted at the pole.):

Our overnight temps started at 0F and ended this morning at -8F. The car was set to start charging at 1:00am and parked outside plugged into our Level 2 charger. So far the car has always been charged in the morning--except this one. This morning it read: 80% and still charging.

I've noticed on cold days before that it will start a slow trickle charge when I plug it in even though its set to charge at 1:00am (presumably it uses the slow trickle charge to slightly warm the battery without having to use the heaters). I'm suspecting that it was too cold to charge at the full Level 2 rate available and just continued to trickle charge it over night (The battery was only 15% full or so when I plugged it in yesterday.)

Either that or I've found a bug in the value charge software....

 

[sefs]

Keep in mind that the battery heaters draw 900W total. So this low current state may just be the battery heaters running. A key give away is when you can hear the battery coolant pump purring away.

 

[jmueller065]

The coolant pump on my FFE is quite quiet. The vacuum pump, on the other hand, is very loud--sounds like an aquarium pump LOL. (As is the fan.)

 

[dmen]

As far as I can tell from myfordmobile, my home level 2 charging isn't taking longer at subzero temperatures. I'm seeing less than 2 hrs to refill from 50%. I know myfordmobile charge times aren't super reliable but I don't usually get unbelievable numbers as others have reported. Plus, yesterday at air temp around -5F, an outdoor Chargepoint unit gave my Focus the usual almost-6 kW of power that I get at warmer temps.
But I'm not using value charging right now, so I generally plug in right after a drive, when the battery is relatively warm. Maybe your battery soaking outside in neg temps for 6+ hrs gets so low that it can't be warmed enough?

I notice the battery TMS pump make a low ghostly hum when I plug my car in at temps below around 20F, but I think the sound is amplified by my garage. I can see maybe not noticing it if you park and plug your car outdoors. I certainly haven't noticed it when plugging in outdoors but I haven't really been listening for it. When I first heard it in my garage I was sure something was busted, but as the car continued to charge just fine and drive fine the next day, I learned to accept it.

 

[jmueller065]

But I'm not using value charging right now, so I generally plug in right after a drive, when the battery is relatively warm. Maybe your battery soaking outside in neg temps for 6+ hrs gets so low that it can't be warmed enough?

It doesn't really soak though: even with value charging set at temps below freezing it does a trickle charge--it even lets you know: at temps warmer than freezing MFM will report waiting to charge and show the start time as the programmed value charge start time. At temps less than freezing it will show waiting to charge as well but the start time will always be the time you plug it in. This behavior has been very reliable for me: >32F it says 1am start, <32F it says start now--so it is actively doing something <32F (trickle charge, running TMS, etc.)

 

[dmen]

Makes sense.

Then I'm not sure why your charging session was prolonged, as for what it's worth mine don't seem to be any longer in the extreme cold. I guess I'd question whether the battery heating system may not be powered sufficiently to keep up against this degree of cold, so even though your car is trying to keep battery warm while waiting for the value window, maybe the battery is cooling anyway.

Tonight should be just about as cold as last night. Be interested to see if the same thing happens for you again.

 

[jmueller065]

Then I'm not sure why your charging session was prolonged, as for what it's worth mine don't seem to be any longer in the extreme cold. I guess I'd question whether the battery heating system may not be powered sufficiently to keep up against this degree of cold, so even though your car is trying to keep battery warm while waiting for the value window, maybe the battery is cooling anyway.

Tonight should be just about as cold as last night. Be interested to see if the same thing happens for you again.

It didn't but then:

• The kid was home from school so I didn't go to work and thus the battery was already 99% charged at 7pm
  I moved the car into the garage (after taking it to a car wash so its clean and "warm")
  Didn't drive the car in this morning so its still in the garage

"warm" in the garage overnight = 25F! LOL
Every time I drive my F-350 I feel like one trip in that negates the months of driving the FFE around! LOL (It was reading 7mpg by the time I got in today)

 

[Fluke]

Probably not applicable with value charging (I don't use it so can't say), but my car has had a charging issue a couple of times. Probably less than a dozen times over the last 1+ years when I get out of the car, close the drivers door, and hook up for charging nothing happens. It will not start charging until I reopen the drivers door and close it again. If I had not looked to confirm the car starts charging, it may not have started the charge on these few instances.

 

[davideos]

Probably not applicable with value charging (I don't use it so can't say), but my car has had a charging issue a couple of times. Probably less than a dozen times over the last 1+ years when I get out of the car, close the drivers door, and hook up for charging nothing happens. It will not start charging until I reopen the drivers door and close it again. If I had not looked to confirm the car starts charging, it may not have started the charge on these few instances.

I've had a few episodes like that, but not for a long time. Other than the value charging issue I had as related to the website/mobile MFM merge, I think it has always been with 120V L1 charging. I do notice from time to time that the LED ring will pulse when I plug it into L2 before value charging begins, but it will shortly go out in a minute or so.