Coolant heater vs. block heater..issues

eastender43 · 08-02-2007, 10:31 AM

It seems block heaters are the rage,and for good reason..

They have a couple inconvenient features,however.

1)You have to plug them in...and REMEMBER to unplug them!

2)They draw alot of amps/watts,so you need an external power source.Wouldn't it be nice if the power source could be the hybrid battery through an invertor?

Better yet,OEM engineered to be seamless,computer controlled,voltage sensitive,etc,etc

3)So I am also wondering if a coolant heater that thermally circulates the coolant through the engine would be a lower watt alternative that could be powered off the hybrid battery..I believe this could draw as little as 100 watts and still be very effective.

4)Or possibly throw a deep cycle battery in the back compartment,dedicated to timer controlled engine warming functions,and being recharged by short cables run to the nearby small 12 volt in the tail.

I am just postulating here...someone with more electical engineering background may be able to help me out here...

bwilson4web · 08-02-2007, 11:52 AM

<div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 09:31 AM) [snapback]489232[/snapback]</div>

Quote:

It seems block heaters are the rage,and for good reason..

They have a couple inconvenient features,however.

1)You have to plug them in...and REMEMBER to unplug them![/b]

If you design the strain relief, backing out or pulling out will handle the unplug.

<div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 09:31 AM) [snapback]489232[/snapback]</div>

Quote:

2)They draw alot of amps/watts,so you need an external power source.Wouldn't it be nice if the power source could be the hybrid battery through an invertor?

Better yet,OEM engineered to be seamless,computer controlled,voltage sensitive,etc,etc[/b]

Not really since the traction battery energy comes from gasoline with extra costs not associated with grid power. But a more intelligent design uses time and temperature control instead of just full on.

Sorry but your other suggestions suffer the same problem of using gasoline power to provide the energy needed. However, exhaust heat recovery might help in the first 5 minutes to accelerate the warm-up but this is not a trivial problem.

Bob Wilson

eastender43 · 08-02-2007, 01:27 PM

Yeah I see your point re:gas energy derivation...

Still would be nice if ,as an option,there was a nicely engineered,user friendly block heater option that would be incorporated into the dash and include programmable timer,warning beeper if you forget to unplug,and a nicely located plugin with a strain release mechanism...

But back to reality...as far as strain relief...are we basically talking about a plug in connector that unplugs easily?Doesn't that increase resistance in the connection quite a bit?Can the connection be lubricated with dielectric grease?

Any other ideas for the disconnect?Sooner or later,I WILL forget to unplug it in the morning,guaranteed.Even a cord hanging in front of the windshield may not be enough...

<div class='quotetop'>QUOTE(bwilson4web @ Aug 2 2007, 10:52 AM) [snapback]489294[/snapback]</div>

Quote:

If you design the strain relief, backing out or pulling out will handle the unplug.
Not really since the traction battery energy comes from gasoline with extra costs not associated with grid power. But a more intelligent design uses time and temperature control instead of just full on.

Sorry but your other suggestions suffer the same problem of using gasoline power to provide the energy needed. However, exhaust heat recovery might help in the first 5 minutes to accelerate the warm-up but this is not a trivial problem.

Bob Wilson
[/b]

David Beale · 08-02-2007, 04:46 PM

Generally around here we try to have the duplex we plug into at about 2-4 ft height above the ground, facing the car. If you back out it will pull the plug out without damage (if you're lucky - the plugs get pretty stiff at -20 and below and don't pull out easily). You do want to properly secure the cord on the car. The best setup uses a short extension cord from the duplex to the car, secured at the wall, and the cord on the car is kept only a few inches long, so it doesn't drag on the road. If you back out without unplugging, the extension cord is left on the ground. Relatively harmless. In this case, you want a cord with the straight female, not a right angle plug. These are usually a single plugin.

It's not hard these days to find electronic timers that turn on by hour and day that are not expensive.

Dielectric grease is a good idea on these, particularly if you are parking outside. Keeps water out of the plug. Makes life less exciting.

As far as your original post, there are "block heaters" that go in-line with the heater hose in the car. These pump coolant in short pulses, and tend to warm the whole block. Very nice, but do require some room in the engine compartment and knowledge of how the heater circuit in your car works. They also draw a lot more than the block heaters we are currently using - like 1000 to 1500 Watts. You do start out with nice warm air blowing from your heater though.

1fixitman · 08-02-2007, 04:49 PM

<div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 01:27 PM) [snapback]489367[/snapback]</div>

Quote:

Yeah I see your point re:gas energy derivation...

Still would be nice if ,as an option,there was a nicely engineered,user friendly block heater option that would be incorporated into the dash and include programmable timer,warning beeper if you forget to unplug,and a nicely located plugin with a strain release mechanism...

But back to reality...as far as strain relief...are basically talking about a plug in connector that unplugs easily?Doesn't that increase resistance in the connection quite a bit?Can the connection be lubricated with dielectric grease?

Any other ideas for the disconnect?Sooner or later,I WILL forget to unplug it in the morning,guaranteed.Even a cord hanging in front of the windshield may not be enough...
[/b]

If you use a timer and turn it off about 10 to 15 minutes before you usually leave then there will not be any current flow to cause the plug to arc and spark which is what leads to a high resistance connection. If you really wanted to do something cool then get a few solar panels, charge controller and two or three 12 V maint free deep cycle batteries and use the solar panels to charge the deep cycle batteries then use an inverter to convert the 12 Volt energy collected that day to run your timer/engine block heater setup. Small fans for ventillation during the charge cycle would be required for safety to vent the hydrogen gasses.
D Rock

usbseawolf2000 · 08-02-2007, 05:00 PM

Since you are US, our Prius come with a thermal bottle that keep hot coolant in there. The next morning, the liquid will still be hot and heating it more may have limit.

Maybe you are thinking about heating the coolant that is not in this bottle?

bwilson4web · 08-02-2007, 05:30 PM

<div class='quotetop'>QUOTE(D Rock @ Aug 2 2007, 03:49 PM) [snapback]489550[/snapback]</div>

Quote:

If you use a timer and turn it off about 10 to 15 minutes before you usually leave then there will not be any current flow to cause the plug to arc and spark which is what leads to a high resistance connection. If you really wanted to do something cool then get a few solar panels, charge controller and two or three 12 V maint free deep cycle batteries and use the solar panels to charge the deep cycle batteries then use an inverter to convert the 12 Volt energy collected that day to run your timer/engine block heater setup. Small fans for ventillation during the charge cycle would be required for safety to vent the hydrogen gasses.
[/b]

Hummm, or perhaps have the strain-relief turn off the current at the socket side first? A solid state relay could handle this nicely and not leave a 'hot plug' on the deck.

Bob Wilson

Tchou · 09-03-2007, 06:23 PM

<div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 06:27 PM) [snapback]489367[/snapback]</div>

Quote:

But back to reality...as far as strain relief...are we basically talking about a plug in connector that unplugs easily?
[/b]

could be inspired from the magsafe plug used to power Macbooks from Apple...

phumpher · 09-03-2007, 07:14 PM

How about a plug and receptacle that auto-eject?

Check this, this or these

donee · 09-03-2007, 08:57 PM

Hi All,

Ok, its winter in Wisconsin, its snowed, and now the sun is out. What do you do ? You run hot anti-freeze/water over the AC expander(cabin cooling coil) from a roof mounted solar hot-water system. Running the AC then makes it run automatically like a heat pump to warm up the engine comparment. HA! The solar hot water heater will need storage, as the sun is going down by 5 PM in the middle of the winter. The hot water gives up its heat to the AC loop, which dumps it in the condensor, and is blown into the engine compartment.

Similarly, one might run the engine block heater on rooftop solar cell.

Not sure which system would yield more energy.

08-02-2007, 04:46 PM	#4
David Beale Senior Member Join Date: Jul 2006 Location: Edmonton Alberta Posts: 2,116 My Car: 2007 Prius Model: Package: B Thanks: 3 Thanked 77 Times in 58 Posts Friends: 0	Generally around here we try to have the duplex we plug into at about 2-4 ft height above the ground, facing the car. If you back out it will pull the plug out without damage (if you're lucky - the plugs get pretty stiff at -20 and below and don't pull out easily). You do want to properly secure the cord on the car. The best setup uses a short extension cord from the duplex to the car, secured at the wall, and the cord on the car is kept only a few inches long, so it doesn't drag on the road. If you back out without unplugging, the extension cord is left on the ground. Relatively harmless. In this case, you want a cord with the straight female, not a right angle plug. These are usually a single plugin. It's not hard these days to find electronic timers that turn on by hour and day that are not expensive. Dielectric grease is a good idea on these, particularly if you are parking outside. Keeps water out of the plug. Makes life less exciting. As far as your original post, there are "block heaters" that go in-line with the heater hose in the car. These pump coolant in short pulses, and tend to warm the whole block. Very nice, but do require some room in the engine compartment and knowledge of how the heater circuit in your car works. They also draw a lot more than the block heaters we are currently using - like 1000 to 1500 Watts. You do start out with nice warm air blowing from your heater though. __________________ Edmonton Alberta "Pearl" is a 2007 Driftwood Pearl Prius.

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08-02-2007, 10:31 AM	#1
eastender43 Join Date: Jul 2007 Posts: 19 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	It seems block heaters are the rage,and for good reason.. They have a couple inconvenient features,however. 1)You have to plug them in...and REMEMBER to unplug them! 2)They draw alot of amps/watts,so you need an external power source.Wouldn't it be nice if the power source could be the hybrid battery through an invertor? Better yet,OEM engineered to be seamless,computer controlled,voltage sensitive,etc,etc 3)So I am also wondering if a coolant heater that thermally circulates the coolant through the engine would be a lower watt alternative that could be powered off the hybrid battery..I believe this could draw as little as 100 watts and still be very effective. 4)Or possibly throw a deep cycle battery in the back compartment,dedicated to timer controlled engine warming functions,and being recharged by short cables run to the nearby small 12 volt in the tail. I am just postulating here...someone with more electical engineering background may be able to help me out here...

08-02-2007, 05:00 PM	#6
usbseawolf2000 HSD PhD Join Date: Sep 2004 Location: Queens, NY Posts: 3,254 My Car: 2006 Prius Model: Package: #3 Thanks: 106 Thanked 178 Times in 111 Posts Friends: 59	Since you are US, our Prius come with a thermal bottle that keep hot coolant in there. The next morning, the liquid will still be hot and heating it more may have limit. Maybe you are thinking about heating the coolant that is not in this bottle?

09-03-2007, 07:14 PM	#9
phumpher um...oh...uh...wa...er Join Date: Jan 2006 Location: where gold was discovered Posts: 40 My Car: 2006 Prius Model: Package: #6 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	How about a plug and receptacle that auto-eject? Check this, this or these

09-03-2007, 08:57 PM	#10
donee Senior Member Join Date: Aug 2005 Location: Chicagoland Posts: 2,244 My Car: 2006 Prius Model: Package: #2 Thanks: 2 Thanked 54 Times in 47 Posts Friends: 0	Hi All, Ok, its winter in Wisconsin, its snowed, and now the sun is out. What do you do ? You run hot anti-freeze/water over the AC expander(cabin cooling coil) from a roof mounted solar hot-water system. Running the AC then makes it run automatically like a heat pump to warm up the engine comparment. HA! The solar hot water heater will need storage, as the sun is going down by 5 PM in the middle of the winter. The hot water gives up its heat to the AC loop, which dumps it in the condensor, and is blown into the engine compartment. Similarly, one might run the engine block heater on rooftop solar cell. Not sure which system would yield more energy.