Chevy Bolt EV Forum banner

1 - 20 of 90 Posts

·
Registered
Joined
·
51 Posts
Discussion Starter #1
Does anyone know what type of heating system will be used with the Bolt? Loss of range in below freezing weather is a concern in areas like upstate NY with our long winters. I have used cabin preheating and seat heating with my current BEV but range is still seriously affected by use of the defroster and cabin heater. It would be better with an energy efficient heat pump system.
 

·
Registered
Joined
·
862 Posts
GM has been strangely silent on this one.

Resistive heating vs heat pump is a BIG deal. And waste heat recovery should also be implemented. Toyota has gone with a "vapor injected" heat pump on the Prius Prime to keep it working in sub-zero temperatures, but there are other versions of heat pumps that also do that.

Heat pump BEV's are the LEAF, i3, Soul EV, e-Golf (SEL only), and upcoming Hyundai IONIQ.

Tesla S/X use waste heat recovery (from the drive motor and electronics) that can be used to heat the cabin and/or battery pack. Additional heat is provided by resistive heating. At the launch of the Model 3, some unspecified "special" HVAC features were touted but not revealed.

The REx version of the i3 has resistive heating - probably because the ICE can/does generate lots of waste heat.

The SE (low cost) version of the e-Golf lost the heat pump (as well as Quick Charging, 7.2 kW L2, leatherette seats/trim, LED headlights, larger touchscreen with navigation, & a few other odds & ends).

The Spark EV uses resistive heating as does the Volt (which also fires the ICE at very low temps, even with a full charge), so a heat pump on the Bolt would be a first for GM.

The lack of information on heating is not encouraging. A heat pump and waste heat recapture are things that GM definitely would brag about, so the silence implies they are not part of the Bolt design.
 

·
Registered
Joined
·
263 Posts
Not sure if this source is reliable but they're saying the Bolt uses resistive heating for the cabin, apparently the most inefficient way of heating. Chevy most likely use a similar heat pump found on the Leaf. Doubt they would follow in Tesla's footsteps in terms of reusing waste heat since GM hates them.
 

·
Registered
Joined
·
862 Posts
Seems like it's going to drain a lot of the battery if the Bolt uses resistive heating. What's a heat pump?
An air conditioner or refrigerator are basically types of heat pumps. But a heat pump operates in "reverse" and uses the phase change to condense heat from the cool air outside the car to warm the cabin.
A resistive heater is like a hair dryer or space heater - the resistance in the heating element causes it to get hot (and glow red/orange like in a toaster) and then air is passed over it to heat the cabin.
 

·
Registered
Joined
·
10 Posts
As a previous Leaf owner, I can attest that during the winter I typically experienced 20-30% reduction in range. Even without aggressive use of the heater and other electronics my range took a significant hit. But if the Bolt's range is 200+ miles I can live with taking a 20-30% hit on range no matter what type of heating system is used.
 

·
Registered
Joined
·
862 Posts
As a previous Leaf owner, I can attest that during the winter I typically experienced 20-30% reduction in range. Even without aggressive use of the heater and other electronics my range took a significant hit. But if the Bolt's range is 200+ miles I can live with taking a 20-30% hit on range no matter what type of heating system is used.
Did you have a LEAF with the heat pump? Especially the improved version fitted in 2013 and late model years?

Resistive heating can take an even bigger bite.
 

·
Registered
Joined
·
10 Posts
As a previous Leaf owner, I can attest that during the winter I typically experienced 20-30% reduction in range. Even without aggressive use of the heater and other electronics my range took a significant hit. But if the Bolt's range is 200+ miles I can live with taking a 20-30% hit on range no matter what type of heating system is used.
Did you have a LEAF with the heat pump? Especially the improved version fitted in 2013 and late model years?

Resistive heating can take an even bigger bite.
Yes, it was the 2013 Leaf with the heat pump. Since my commute to work is about 68 miles round trip it was very difficult during the winter. Summer commuting was not an issue with the A/C.
 

·
Registered
Joined
·
31 Posts
I can confirm this - I had a 2013 Leaf SV with heat pump - the range was around 60-65 miles in 20 degree (F) weather. I'm not sure if it was the heater, battery temperature (I don't think the Leaf had a battery heater) or the increased air resistance of the colder air - or a combination of all three. I had to drive quite a few miles with no heat to make it home :-(
 

·
Registered
Joined
·
1,486 Posts
If the Bolt EV is going to see a 30% reduction (worst case scenario), then it could lose 60 miles out of the 200 mile range. Depending on where you're commuting to, 140 miles should be enough and you'll be able to stay warm while getting there.

Just wish they would tell us more about how the cabin is heated so we're not guessing and worrying.
 

·
Registered
Joined
·
862 Posts
30% is a likely scenario - IF it utilizes a heat pump.
40-50% is entirely possible in extreme cold if it relies on resistance heat. Battery chemistry, garaged or outdoors, need for defrost, etc. all play into it.
 

·
Registered
Joined
·
31 Posts
At this price point, my guess would be resistance heat to keep costs down. However, even with the higher drain, the range should still be within my current commute. Hopefully, more information will be forthcoming soon.
 

·
Registered
Joined
·
862 Posts
Does the new Volt have a heat pump? That may be a good indicator to see if Chevy will install one in the Bolt.
No, but not a good indicator as the Volt has an ICE (where 70% or the energy in gasoline is turned into heat).
The Volt has an ERDTT mode that is much debated among owners. Below a certain temp, the engine will start even with a completely charged battery for sole purpose of providing heat to the cabin.
ERDTT = Engine Running Due To Temperature.

I still believe that since Chevy is not listing the heat pump as a feature and talking about the benefits it provides, then the Bolt will not utilize one.
 

·
Registered
Joined
·
322 Posts
I agree that a resistive heater is likely, using DucRider's logic.

The benefits of a resistive heater, which I'm not sure has been said yet, is that it operates independently of the outdoor temperature and it has a more immediate response during a cold start.

However, preheating while plugged in should be the standard practice to avoid the battery usage, then the differences between the technologies becomes less relevant to just maintain temperature.

Current Tesla's have a resistive heater plus a heat transfer loop that routes excess heat from the battery and motor, if I understand it correctly. How the Model 3 will operate is anyone's guess.
 

·
Registered
Joined
·
862 Posts
Current Tesla's have a resistive heater plus a heat transfer loop that routes excess heat from the battery and motor, if I understand it correctly. How the Model 3 will operate is anyone's guess.
Model S/X's use the loops to harvest heat from the motor(s) and the electronics (primarily the inverter). The heat is directed TO the battery and/or the cabin.
Lithium batteries happy place is around 70 degrees. That's where they are more efficient and have the greatest capacity and power rating. In cold weather it is of great benefit to warm the pack, it allows for more regen and overall greater efficiency (range).
 

·
Registered
Joined
·
1,486 Posts
Warming up the car while plugged in would be the ideal situation, just doesn't happen all the time if you travel somewhere that doesn't have charging stations readily available. Just wish Chevy would release more info soon so we're not just speculating.
 

·
Registered
Joined
·
322 Posts
I'll just reiterate DucRider's theory, if GM was proud of the heating system they would have already released information about it.

Basically, don't get your hopes up!
 

·
Registered
Joined
·
1,486 Posts
Guess we'll be seeing a 40-50% reduction in range since we're most likely only getting resistive heating.

Do we really have to warm up the car before driving off?
 
1 - 20 of 90 Posts
Top