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Discussion Starter · #1 ·
At this time of year, it always makes me wonder why GM never programmed in a block heater function.

I can't see why not. It's purely a software programme it has all the hardware already installed.

If you heat up the HVAC circuit and run it 'OFF' for more than 5 mins it goes cold. If you heat it up with the engine, it delivers heat for around 25 mins in 'OFF'.

Why not use the engine block as a thermal store? On electric heating it could heat up the engine block too and store thermal energy there. Also means you get cleaner more efficient engine running if you start up early in the trip on hold.

For all the clever thinking in the Volt, you sometimes wonder if it wasn't simply a bit of a rush job at the end. But if so, why not have implemented it for the Volt 2? It could be an extra option buried in the menus.
 

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Block heaters are normally used to make sure that little starter motors and tiny lead acid batteries can crank big engines. The Volt obviously has no need for this aspect - the motors are powerful enough to start the engine under any circumstances.

There's some validity to the suggestion of a thermal store is interesting, though. It'll eat significantly more total energy than not heating the engine at all, but it transfers a bunch of the requirement to shore power instead of the battery pack.
 

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Discussion Starter · #4 ·
You're likely to do what most others do, install one :)
has anyone done this already (on a Volt)?

I was considering doing just that once it is out of warranty. Could rig it to the inlet socket via a timer.

A 100kg of iron cooling down from 80C to 45C would deliver around 1kWh of thermal energy. Why try to ram an extra kWh of battery pack into the car when you already have that energy storage feature there already... and useful just at the time of year when you really need that extra kWh?
 

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At this time of year, it always makes me wonder why GM never programmed in a block heater function.

I can't see why not. It's purely a software programme it has all the hardware already installed.

If you heat up the HVAC circuit and run it 'OFF' for more than 5 mins it goes cold. If you heat it up with the engine, it delivers heat for around 25 mins in 'OFF'.

Why not use the engine block as a thermal store? On electric heating it could heat up the engine block too and store thermal energy there. Also means you get cleaner more efficient engine running if you start up early in the trip on hold.

For all the clever thinking in the Volt, you sometimes wonder if it wasn't simply a bit of a rush job at the end. But if so, why not have implemented it for the Volt 2? It could be an extra option buried in the menus.
For a while, all GM cars sold in Canada had an immersion block heater installed. It seems like it would be a good idea, especially for those with a dread of ERDTT. It also used to be an easy DIY install but draining and refilling the cooling system is not as simple as it used to be. Perhaps an external, clamp-on type would work.
 

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The Volt and many of the newer GM vehicles now use a synthetic oil that never get thicker or freeze up under extremely cold conditions, so the oil will always flow inside the gas engine block. If you don't believe me, just take out a sample (a few ounces) of its engine oil, and try to freeze it under the same exterior cold conditions. Since the larger HV battery is thermally conditioned, and the electric motor/generator is also protected, these will always turn the engine on when needed, and the oil will not limits their power tranfer to turn the gas engine. No engine block (or 12 VDC battery) heater is ever needed!

Remember that there is a 100% guaranteed permanent solution to prevent the extreme cold and the ERDTT: move south to warmer temperatures. You Volt, your health, and your wallet will thank you!
 

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Too many people already have that idea, prefer the frigid north, on the plus side is the battery will last longer up here ;)

Agreed, never had a problem with Volt being able to start the engine even with overnight low near -20F with the car unplugged and outside (so no extra help).
 

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The Volt doesn't need a block heater to make sure the engine starts. Not with a motor-generator and a 370V battery. Using the engine block to store thermal energy doesn't sound like a good idea. The engine is uninsulated. Judging how fast my last 4 cylinder car cooled off in very cold weather, I'd say the idea of using the engine to store thermal energy is a bad idea.
 

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The Volt and many of the newer GM vehicles now use a synthetic oil that never get thicker or freeze up under extremely cold conditions, so the oil will always flow inside the gas engine block. If you don't believe me, just take out a sample (a few ounces) of its engine oil, and try to freeze it under the same exterior cold conditions. Since the larger HV battery is thermally conditioned, and the electric motor/generator is also protected, these will always turn the engine on when needed, and the oil will not limits their power tranfer to turn the gas engine. No engine block (or 12 VDC battery) heater is ever needed!

Remember that there is a 100% guaranteed permanent solution to prevent the extreme cold and the ERDTT: move south to warmer temperatures. You Volt, your health, and your wallet will thank you!
Not needed to get the car going, maybe, but to provide some ready heat right from startup. My VW TDI started at -35C, shaking and smoking, with 0W40 synthetic oil and no block heater but it was a long time before it was comfortable inside. Use of a block heater would probably minimize ERDTT in the Volt.

And your suggestion to move won't work for those of us who don't like hot weather, and are more than happy to live this side of the border.
 

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If you have a plug for the heater why not just plug the car in?
 

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If you have a plug for the heater why not just plug the car in?
That's a good (and obvious) question. 10 or 20 minutes of pre-heat would do the trick for the cabin, doesn't avoid ERDTT though if that's important. I'm assuming ERDTT would be triggered by the ambient temperature then stop if the coolant is warm enough.
 

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Discussion Starter · #13 ·
Not sure a half of the respondents have considered what I put.

The engine can store 1kWh of heat and deliver usable cabin heating for around 25 mins (at 0~5C) in 'OFF' and no engine. Heating the cabin up and warming the HVAC coolant circuit up lasts around 5 minutes in 'OFF'. Then you have to start burning off electricity (or gas).

I never mentioned a problem in cranking the engine. Not remotely what I was thinking about.

Have you guys never heard of storage heaters?
 

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Not sure a half of the respondents have considered what I put.

The engine can store 1kWh of heat and deliver usable cabin heating for around 25 mins (at 0~5C) in 'OFF' and no engine. Heating the cabin up and warming the HVAC coolant circuit up lasts around 5 minutes in 'OFF'. Then you have to start burning off electricity (or gas).

I never mentioned a problem in cranking the engine. Not remotely what I was thinking about.

Have you guys never heard of storage heaters?
I think you might have an inflated idea of what a "block heater" actually does which is keeps the oil resting in the oil pan warm (warm as in above freezing temperatures...not hot) so that it flows more easily on start.

that's it, that is all it does.

It's not going to give you a hot, or even vaguely warm engine block (just the oil pan) and it'll do almost nothing towards pre-warming your coolant fluids to give you cabin heat.

Block heaters used to be a pretty good idea for big displacement gasoline engines with dino-juice in the pan in very cold climates, and were just about essential if you wanted your 80's Diesel to start in the winter, but we've pretty much gone beyond those requirements with better engineering and synthetic lubricants. Well, unless you live near the 66'th parallel or something.
 

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Adding a block heater with a select option operable only when plugged in on 220v might be nice. But it is an extra cost, it's not needed most of the time and a couple of minutes of engine warm up would yield the same result.
 

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I think you might have an inflated idea of what a "block heater" actually does which is keeps the oil resting in the oil pan warm (warm as in above freezing temperatures...not hot) so that it flows more easily on start.
that's it, that is all it does....
This is not true.
There are 'Pad heaters' that can be epoxied to the oil pan to keep the oil warm: https://smile.amazon.com/Kats-24150...80454544&sr=1-1&keywords=kat's+hot+pad+heater

Then there are two types of actual block heaters: The external circulating can type and the drain plug/freeze plug type that go into the block.
Both of these types heat the coolant and through convective circulation heat the entire engine.
Here's an example of one I plan on installing in my Element: https://smile.amazon.com/Kats-11419...automotive&vehicleId=5&vehicleType=automotive

Some Canucks and Alaskans might use both at the same time. Baby it's cold outside.

As said the Volt engine cooling system may not be a simple drain and refill for installing one.
And there would/could be warranty issues.
A pad heater could be added to the oil pan, w/o dikin with warranty issues, but that won't heat the entire engine much.
I've installed them on many of my previous cars. The Prius had an official accessory one and it worked great.
A pre-warmed care is easy on the engine and the occupants!
 

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This is not true.
There are 'Pad heaters' that can be epoxied to the oil pan to keep the oil warm: https://smile.amazon.com/Kats-24150...80454544&sr=1-1&keywords=kat's+hot+pad+heater

Then there are two types of actual block heaters: The external circulating can type and the drain plug/freeze plug type that go into the block.
Both of these types heat the coolant and through convective circulation heat the entire engine.
Here's an example of one I plan on installing in my Element: https://smile.amazon.com/Kats-11419...automotive&vehicleId=5&vehicleType=automotive

Some Canucks and Alaskans might use both at the same time. Baby it's cold outside.

As said the Volt engine cooling system may not be a simple drain and refill for installing one.
And there would/could be warranty issues.
A pad heater could be added to the oil pan, w/o dikin with warranty issues, but that won't heat the entire engine much.
I've installed them on many of my previous cars. The Prius had an official accessory one and it worked great.
A pre-warmed care is easy on the engine and the occupants!
The proposal under discussion would be an operating mode wherein the Volt used the 6kW cabin coolant heater and circulating pump to run hot coolant throughout the engine block, functionally the same as a circulating block heater. All of the hardware is there already - it just requires a mode of operation GM doesn't normally allow - circulating coolant through the engine side while the engine is cold.

I suppose an enterprising soul could achieve this without new firmware from GM by bypassing/disconnecting the valve so it stays cross-linked and then preheating the car repeatedly.
 

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Some users have had this by accident - perhaps you could figure a way to make a switch to do so, like the ERDTT folks.

When the mixing valve is broken, stuck in the open position, the cabin heater is heating the entire coolant loop, engine and cabin. Thus it was taking forever to get heat out of it and into the cabin.
If you could purposefully do this, and remote start your car a few times, you'll have a large pool of hot coolant which your engine will absorb.

However, the whole premise of a block heater isn't really necessary for a volt.
In a traditional ICE-only it
-keeps the oil warmer so it moves more easily (small starter motor is not strained as much, battery recharges faster from each start)
-keep the engine slightly above freezing temp so it warms up faster and uses less fuel (goes into closed loop mode quickly)
-"happy" engine without such a harsh start

In the volt
-there is 55kW of power available to spin the engine - no worries there
-quality synthetic oil does not suffer as much from cold temps
-the engine is babied for a ~50s warmup mode, and is never run as hard as a cold ICE-only car would run it:
-> the engine output doesn't need to match the vehicle output in a volt (battery makes up the difference), but it must in an ICE. If you know what a block heater is, you know how sluggish engines can be until they warm up. Volt can make the best of what it's got in the meantime and you never know the difference.
-> with no idle time, the engine warms up much faster than a traditional ICE would for the same on time. "Idle" is really like 1/3 throttle.
 

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Discussion Starter · #19 ·
I'm simply talking about a heater to heat the engine block. A 1kWh thermal store already there, already capable of being heated up off electricity. No hardware needed, just software control to keep that coolant bypass flap open.

That saves a ~1/10th of a gallon of gas in heating, but still means it's a kWh you don't have to pull from the battery.

Heck - if it isn't worth saving the equivalent of a kWh of gas, then the next kWh isn't worth saving either, or the next 8 or 12kWh, so just go back to a gas car if none of those kWh's are worth saving by using electricity!
 

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Not sure a half of the respondents have considered what I put.

The engine can store 1kWh of heat and deliver usable cabin heating for around 25 mins (at 0~5C) in 'OFF' and no engine. Heating the cabin up and warming the HVAC coolant circuit up lasts around 5 minutes in 'OFF'. Then you have to start burning off electricity (or gas).

I never mentioned a problem in cranking the engine. Not remotely what I was thinking about.

Have you guys never heard of storage heaters?
Actually, I did consider what you said in the original post, then went with the flow. My fault, blame it on my ADD.

Terminology is a bit of a problem here and your use of 'block heater' turned into a red herring. A 'block heater', to me, is a heating coil that fits into a frost plug and heats the coolant and the block directly. They are typically about 1500 watts and help both cranking and cabin heat in really cold weather.

Oil pan heaters fit beneath the engine and warm the oil pan and only really help cranking.

There are other heaters that plumb into a coolant line, typicall the lower rad hose, and warm and circulate the coolant.

So, to address your real point: it's an interesting idea, but in the real (Northern North America, for instance) where winter temperatures are rarely as high as the 0-5 degrees in your example I think the benefit would be brief and minimal.

Some time ago BMW did some interesting work on collecting and retaining waste heat from their ICEs, but I'm not sure much of it saw production. That, of course, only applies to fuel burning engines but apparently they did not feel it had a net positive result.

And no, I'm not familiar with storage heaters. Central forced air gas does it for me. Others use electric resistance heaters.
 
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