[2Slow.]

Someone just properly tested 45e to see if ICE warm up during Electric Only mode drive.

Interesting results:
http://frey-bafang.patransformers.com/2022/10/28/bmw-x5-45e-cold-engine-start-review/

link

It's more complex than I expected.

[biterror]

The test should have been done at -29 C ambient, not +29 C...

[2Slow.]

Originally Posted by biterror

The test should have been done at -29 C ambient, not +29 C...

Makes no difference, they measure temperature rise. Same at any ambient.

BMW X5 G05 cooling circuit appear to be better designed than heating circuit
Main market been California?

[eelnoraa]

The key component of an engine should be warm is the oil, which also means internal components. Not necessary equal to exterior temperature. I wonder what is the oil temp?? Typical engine components and oil operating temp is 100C/212F range. Raising engine exterior to 50ish C is better than nothing, but still very far from where one should start pushing a turbo charged engine.

The part where the article suspects the reason for low engine power kind of make sense. If battery and additional electronics for EV is cooled by the intercooler loop, so intake air is warmer, less power even for same tuning.

But if we take one step back, the demographic for 45e isn't really people who looking for best performance car. Revving engine a few times for a few second when it is cold may not be as bad as people want to believe. ICE is a lot tougher than that. I would think 4-5K RPM should be more than enough to get out of potential dangerous situation. Now if you take 45e to drag race without prior warm up, and use EV/hybrid and let engine kick in to high RPM from cold and still, then it isn't the smartest choice.

[2Slow.]

I noticed that 75% of mine miles are EV. This means, by the time car done 1 million miles, only 250K are on ICE.
Pre - B58 is known to last pass 250K

[Scientifix]

"– Electric air heater for cabin"
So does this electric heater use the main big battery? What happens when that is completely depleted? In that case does it use the heat generated by the ICE like other regular ICE automobiles?

[eelnoraa]

I think if ICE on, it will generate electricity to charge HVB, and in turn, run electric heater. A very inefficient way to generate heat. There doesn’t seem to be a heating loop for cabin from ICE radiator circuit.

[2Slow.]

To solve this cabin heating issue, Tesla uses reverse cycle AirConditioning

[LarsOtium]

Good thing I didn’t read this before I bought the 45e! This thing is soooooo complicated.

On the other hand, it makes me glad I bought extended warranty.

[nZtiZia]

Originally Posted by Scientifix

"– Electric air heater for cabin"
So does this electric heater use the main big battery? What happens when that is completely depleted? In that case does it use the heat generated by the ICE like other regular ICE automobiles?

Originally Posted by eelnoraa

I think if ICE on, it will generate electricity to charge HVB, and in turn, run electric heater. A very inefficient way to generate heat. There doesn't seem to be a heating loop for cabin from ICE radiator circuit.

be assured the HV battery is never 'completely depleted', but it can reach a level so low that certain components will not operate until some charge is restored.

according to schematics, radiant heat from a warm ICE isn't captured or utilized to provide heat to the cabin. HVAC (AC and heat) is run completely off HV battery power. I performed a test earlier this year in light of vehicles being stuck/idle on the highway for several hours due to a winter storm accident. folks questioned what the 45e would do in this scenario with a 'depleted' HV battery.

TL;DR, the ICE will cycle on and off to maintain enough HV battery capacity to keep HVAC running:
https://www.bimmerpost.com/forums/sh...php?p=28532264

[eelnoraa]

Originally Posted by 2Slow.

To solve this cabin heating issue, Tesla uses reverse cycle AirConditioning

It is as simple as calling it t a “heat pump”.

[jad03060]

The current 45e does not use a heat pump, but BMW has used them, and did on the i3, and probably other vehicles. The i3 was a clean sheet of paper design, where they worked every small detail to keep the weight down, and things as efficient as they could. That's harder to do with a 'conversion' of an existing model. We'll see more optimization and efficiency as the design evolves.

[biterror]

Originally Posted by eelnoraa

I think if ICE on, it will generate electricity to charge HVB, and in turn, run electric heater. A very inefficient way to generate heat. There doesn’t seem to be a heating loop for cabin from ICE radiator circuit.

Again, I had the guys at my local BMW service check the documents and they said that the heat generated by the ICE is used to heat the cabin. The cabin air is heated by the same system as in non-hybrid cars. In electric mode, the coolant is heated by an electric heater and the coolant heats the air.

If the car was using the HV battery to heat the cabin even when running on ICE, we should see fuel consumption rising sharply in cold weather. I haven't noticed it happening when driving 1000 km's at -20 to -30 degrees C. I think heating the cabin in such temperatures requires at least 3 kW of power. If the ICE efficiency is 30% (including the generator etc.), you would need one liter of gas per hour to keep the cabin warm. On my 12-hour trip, this would use 12 liters of extra fuel. Not happening.

[nZtiZia]

Originally Posted by biterror

Again, I had the guys at my local BMW service check the documents and they said that the heat generated by the ICE is used to heat the cabin. The cabin air is heated by the same system as in non-hybrid cars. In electric mode, the coolant is heated by an electric heater and the coolant heats the air.

If the car was using the HV battery to heat the cabin even when running on ICE, we should see fuel consumption rising sharply in cold weather. I haven't noticed it happening when driving 1000 km's at -20 to -30 degrees C. I think heating the cabin in such temperatures requires at least 3 kW of power. If the ICE efficiency is 30% (including the generator etc.), you would need one liter of gas per hour to keep the cabin warm. On my 12-hour trip, this would use 12 liters of extra fuel. Not happening.

if that's the case, how do your BMW guys explain the following notification which clearly shows HVAC (Heating, Ventilation, AC) is dependent on adequate HV battery capacity.

in the below photo, the guy started his vehicle and immediately got the notification. it can be deduced the ICE is running because there's no HV battery capacity to run in Electric (yes, he can select Hybrid or Adaptive, but the electric part wouldn't be active; the ICE would run initially until it replenishes the HV battery.) QUESTION: if heating is provided by the ICE, why would HVAC need to be deactivated? he should have radiant heat from the ICE into the cabin without worry.

FYI, several owners in the north atlantic have confirmed they get this notification when it's very cold. according to your BMW guys, they should be getting radiant heat from the ICE from the get-go, but they reported being without heat despite the ICE running. the HV battery needed to regain some charge first.

[nZtiZia]

biterror let's approach the question of ICE vs HV battery-powered heat another way. the owner's manual states:
"if stationary climate control is used during the charging process, less air conditioning capacity will be required while driving. this optimizes the range."

a few terms to clarify:
1) "stationary climate control" means preconditioning
2) "air conditioning" doesn't mean cooling only. it means conditioning the air by cooling or heating it.
3) "range" is electric range.

so, if heating (which is one component of HVAC) isn't dependent on the HV battery while the ICE is running, why would the engineers put the above statement in the manual at all? they clearly show there's a connected dependence between HVAC and the HV battery: HV battery capacity reserved to drive the vehicle versus heating the vehicle (which is very energy-consuming at beginning of the drive) optimizes electric range. IF the radiant heat from the ICE heats the cabin, we needn't worry about any ill effect on HV battery capacity, but since HV battery capacity is used to heat, there are consequences if not managed properly.

[jiggie]

Originally Posted by biterror

Again, I had the guys at my local BMW service check the documents and they said that the heat generated by the ICE is used to heat the cabin. The cabin air is heated by the same system as in non-hybrid cars. In electric mode, the coolant is heated by an electric heater and the coolant heats the air.

If the car was using the HV battery to heat the cabin even when running on ICE, we should see fuel consumption rising sharply in cold weather. I haven't noticed it happening when driving 1000 km's at -20 to -30 degrees C. I think heating the cabin in such temperatures requires at least 3 kW of power. If the ICE efficiency is 30% (including the generator etc.), you would need one liter of gas per hour to keep the cabin warm. On my 12-hour trip, this would use 12 liters of extra fuel. Not happening.

They are wrong. The HVAC is Electric.

How am I preconditioning my vehicle in the cold if the ICE hasn't run in 14 hours? Ever notice you can't precondition the vehicle with no charge?

[biterror]

Originally Posted by jiggie

They are wrong. The HVAC is Electric.

How am I preconditioning my vehicle in the cold if the ICE hasn't run in 14 hours? Ever notice you can't precondition the vehicle with no charge?

How could you precondition the vehicle with heat from the ICE if the ICE is at -30 degrees C? Of course it's not possible.

If the ICE is cold, you need the HV battery to heat the cabin. There's an electric heater for this purpose, heating the coolant (they told me).

If the ICE is warm, my dealer told me the coolant is used to heat the air the same way as in X5 40i. Maybe they were wrong, even though they were looking at the technical documents on their computer.

The 40i uses the heat from the engine to heat the cabin. Why would BMW remove that functionality from the 45e?

I'm not sure about X5, but I know that some cars use the HVAC compressor even when heating the cabin - to dry the incoming air to prevent fogging. If the 45e does this, then it may need the HV battery for HVAC even when it's using the heat from the ICE.

Anyway, I would expect the fuel consumption to rise significantly in the Nordic winter if the cabin was heated using electricity. On a 1000 km trip, the average consumption was 7.6 l/100 km both in summer and in winter and I have seen 8.5 or 8.6 l/100 km both in summer and in the coldest winter (around -30 degrees C). Can't see any correlation between outside temperature and consumption on these long trips.

I tried to reach some technical specialist at BMW Finland, but they said there are none. However, they promised to try to find an answer to this question and get back to me. I'll let you know if they do. In the meantime, if someone has access to the BMW technical documents, maybe he/she could study them and share some wisdom with us

[nZtiZia]

Originally Posted by biterror

...
I'm not sure about X5, but I know that some cars use the HVAC compressor even when heating the cabin - to dry the incoming air to prevent fogging. If the 45e does this, then it may need the HV battery for HVAC even when it's using the heat from the ICE.
...
I tried to reach some technical specialist at BMW Finland, but they said there are none. However, they promised to try to find an answer to this question and get back to me. I'll let you know if they do. In the meantime, if someone has access to the BMW technical documents, maybe he/she could study them and share some wisdom with us

tech docs are located in the following thread. it's been available for any to peruse for some time.
https://g05.bimmerpost.com/forums/sh....php?t=1563063
i thought i posted the screenshots from the G05 tech docs in this forum, but if i did, they're a pain to find. maybe it was in the FB group. either way, Electrical heating is stated 4 times. as mentioned before, the schematics in these docs do not support their claims that radiant heat from the ICE is directed into the cabin.

as mentioned in the owner's manual, the 45e has condensation sensors (last screenshot). the AC compressor is used which is also listed in the tech docs (screenshots 2 to 4)

[biterror]

Sorry, should have mentioned that I have read those docs, but as you say, they aren't very helpful here.

[finn123]

Originally Posted by biterror

Sorry, should have mentioned that I have read those docs, but as you say, they aren't very helpful here.

It seems like it makes sense what the dealer says.

Here is how the heater looks like - https://www.ebay.com/itm/12502125533...MAAOSwNvdhoM2K.

As you can see it’s a dumb heater with water in and out. I think It must be connected to the inner coolant circle, which is either heated by the engine or the heater itself. Not doing that will just make the entire system more complex. It’s basically an electric webasto

My another guess is that all the messages about inability to use HVAC when the HV battery is drained relate to A/C and the cooling ability as the A/C compressor is electric. It has nothing to do with heating.

[Di3s3l_Power]

^makes sense. Perhaps the people getting the messages had the heat with AC on, this showing HVAC not available.
Perhaps, having heat without AC will not trigger the messages.

How about the HVAC fans? They too need need electricity, but assume even the if the battery is depleted should have some juice left for fans but not AC

[finn123]

Originally Posted by Di3s3l_Power

^makes sense. Perhaps the people getting the messages had the heat with AC on, this showing HVAC not available.
Perhaps, having heat without AC will not trigger the messages.

How about the HVAC fans? They too need need electricity, but assume even the if the battery is depleted should have some juice left for fans but not AC

I bet they use 12v battery.