No heat on in BEV

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BMW4Me

Well-known member
Joined
Jun 13, 2014
Messages
84
Location
Washington, DC
So the folks at my office complex are kind enough to let me plug into a wall outlet every now and again when I am running low or need a top-off.

When plugged in, I usually estimate my departure time so that the vehicle pre-heats. Today was especially cold outside, teens to low 20s, so I was especially looking forward to having a warm car as it was charging on the lowest floor of the indoor garage.

When I got to the car, at the prescribed time this afternoon, the car was still charging and I could hear the fan pumping air into the cabin. The odd thing was that it felt quite cool.

I didn't think much about it, figuring that maybe I had set the wrong departure time and that it had only just started the fan. However, once outside the building, I kept on adjusting the thermostat and even re-started the car while waiting at a traffic light. But I just could not get any heat and it was getting quite cold in the cabin with the sub-zero outdoor temperatures.

Fortunately, the seat heaters worked and helped get the chill out of the air and me, after I shut the fan completely off.

I was able to get hold of the service manager at my dealership who will have a loner for me tomorrow. So that's the first (actually, second ;) ) order of business for Valentines Day!

Any similar experiences?
 
By wall outlet, you mean a 120V Level 1? If so, that ~12 amp draw, combined with the extreme cold, is probably the reason for the delayed heating. I suspect the dealer will find nothing wrong.

If you were plugged into a L2 240V and this occurred, then you probably have an HVAC problem.
 
The colder the temperature, the less heat that is available to pump into the car. Does anyone know whether a resistive heater is included as a backup for the heat pump when temperatures are very low?

I am surprised that no EV manufacturer offers a gasoline/diesel/alcohol auxiliary heater. In cold weather, a hydrocarbon heater would be a significant range extender that would make driving an EV in cold weather comfortable.
 
alohart said:
I am surprised that no EV manufacturer offers a gasoline/diesel/alcohol auxiliary heater. In cold weather, a hydrocarbon heater would be a significant range extender that would make driving an EV in cold weather comfortable.
What is even more surprising to me is the fact that i3 REx is using fluid to transfer heat from resistive heater to the cabin. It also uses fluid to cool down the REx. But those fluids are completely separate. How hard could it be to add small heat exchanger that would take some heat from the REx and pump it into cabin when the REx is running? That would lower electric load significantly making REx's job of holding the SOC so much easier.
 
I think the added complexity of the piping and another heat exchanger, considering the REx ideally, never runs, is a waste of resources.

The BEV in the USA comes standard with a heat pump. The REx , and those without the heatpump elsewhere, have resistance heating like a big toaster. Does anyone know if the BEV with heatpump has resistance heating backup for when the temps are really low? Some of the better heat pumps these days can make reasonable heat down to as low as -20F. Not too many years ago, they couldn't, and you'd have no choice when the temp was low but to have a resistance heat backup.

Note, if you're in either Eco mode while driving, it can restrict the heat output, and in EcoPro+, essentially disable it unless it detects the window fogging up.

WHen it's really cold, I've seen my BEV draw 20A during a preconditioning- more than the L1 unit can provide, so that would also slow things down.
 
Today I took it in to the dealer. Before I left I preconditioned from app. Fortunately, I did have a heated vehicle. Let's see what they find...
 
BMW4Me said:
Today I took it in to the dealer. Before I left I preconditioned from app. Fortunately, I did have a heated vehicle. Let's see what they find...
Were you plugged into an L2?

In any event, look forward to hearing what service says.

From BMW Group University, a white paper on the i3's heating and A/C systems:
http://www.kneb.net/bmw/I01/08_I01%20Heating%20and%20AC%20Systems.pdf
 
Grrr.

Same thing happened to me tonight. 50° out.

Topped up at work. Got to the car with 100% and still plugged in. Climitazation set and I could hear the blower.

Car was ice cold and blowing cold air. Kept blowing cold for my 50 mile drive to pick up father in law at the airport, fresh from Hawaii, wearing sandals at midnight.

At least the seat heater worked! I turned the blower off and switched to manual recirc.

I'm hoping it's a software thing that will fix itself, but I'll make an appointment with service because I can't be driving a Frigidaire.
 
Update: the car made heat this morning. Not sure if I should take it for service or wait for it to happen again. I think it's a software issue.

Yesterday I fast charged to 75%, drove to work and continued my charge via level 1 like I do every day.

The estimated time to 100% displayed by the car didn't match my expectations, so I unplugged, restarted, checked that my charge setting was set to maximum, and plugged back in. The estimated charge time decreased by about an hour, close to what I estimated.

I think somehow I stumbled across a logic bug that prevented the heater from activating. However, I did turn off the car for a few minutes at the airport, the midpoint of my drive, and that didn't cure the problem.
 
I have found that even if the outside temperature is cold, if its sunny out the interior of the car will warm up (like a green house) and when you tell the car to pre-condition via Connect, the A/C may kick on depending on how warm the interior of the car actually is. Happened to us yesterday at the Mall. Was about 45F outside with lots of wind so it felt cold to us walking into the Mall. Ten minutes before we wanted to depart I used Connect to pre-condition the car. When we got to the car, it was blowing cold air into the cabin.
 
It appears as if the I3 with an RX is lacking when it comes to cold weather use. GM uses a cold weather protocol for additional battery and cabin heat.

It would seem logical the i3 RX could be activated during cold weather and the coolant used in a heat exchanger to heat the battery and cabin and save the wasted energy used to heat the i3. Another plus when the RX was running, it would maintain battery level during this heat cycle.

On our Volt or ELR once the temperature gets below 32 degrees the Volt automatically starts the engine and warms it to 200+ degrees then shuts back off again. Once the engine drops in temp to around 150 degrees, the processor starts the engine and cycle begins again. This conservative running every 10-15 minutes provides major heat for the cabin and heats the battery as well to maintain best efficiency. In addition, this cycle of running also conserves the batteries charge.

Best Regards - Mike


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i3.jpg
 
The only cabin heating in an i3 REx is from resistance heating. The BEV has a heat pump and the resistance heaters, but doesn't turn the resistance heaters on unless it's too cold for the heat pump to be efficient.

It would seem to me, running an ICE for short times periodically, would be fairly inefficient.

Battery heating only happens via resistance heaters, and only if you set a departure time and have it plugged in. It can take up to 3+ hours to reach optimum temperature if it's very cold out.
 
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