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Coolant heater vs. block heater..issues

Discussion in 'Gen 2 Prius Technical Discussion' started by eastender43, Aug 2, 2007.

  1. eastender43

    eastender43 Junior Member

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    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...
     
  2. bwilson4web

    bwilson4web BMW i3 and Model 3

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

    eastender43 Junior Member

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    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>
     
  4. David Beale

    David Beale Senior Member

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    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.
     
  5. 1fixitman

    1fixitman Member

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    <div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 01:27 PM) [snapback]489367[/snapback]</div>
    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
     
  6. usbseawolf2000

    usbseawolf2000 HSD PhD

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    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?
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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

    Tchou Member

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    <div class='quotetop'>QUOTE(eastender43 @ Aug 2 2007, 06:27 PM) [snapback]489367[/snapback]</div>
    could be inspired from the magsafe plug used to power Macbooks from Apple...
     
  9. phumpher

    phumpher um...oh...uh...wa...er

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  10. donee

    donee New Member

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    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.
     
  11. n8kwx

    n8kwx Member

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    <div class='quotetop'>QUOTE(Tchou @ Sep 3 2007, 04:23 PM) [snapback]506442[/snapback]</div>
    I haven't installed my block heater yet, but I was thinking the exact same thing. Amazing what those Dell owners miss out on! ;)

    The arrangement would be the same. The "jack" (metal end) would be on the car. The magnetic plug would be the 120v input. I would also create a circuit to measure the current draw of the heater. If it is too high or too low the 120v input would be shut off automatically. This would prevent plug from being "live" when not connected to the car. And don't forget the ground fault interrupter (GFI) AC outlet.
     
  12. JimboK

    JimboK One owner, low mileage

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    <div class='quotetop'>QUOTE(phumpher @ Sep 3 2007, 07:14 PM) [snapback]506464[/snapback]</div>
    They work well in the vehicles they are designed for -- emergency vehicles (which I drive). But the plug is contained within a recessed receptacle mounted on the body of the vehicle. Not something I would choose for my car. Now if someone could come up with something that accomplishes the same thing with my existing EBH plug, I'm in.
     
  13. racerbob

    racerbob Member

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    The auto eject outlet could be mounted under the car in the rear or through the bumper where most of the unit would be inside of the bumper. They work great. We have them on our SUV's in the town's FD. They just power up a maintenance charger since block heaters are not necessary in S FL.
     
  14. donalmilligan089

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    How to install a coolant heater on 2006 prius Where can I buy one
     
  15. IABoy

    IABoy Junior Member

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    For my old car (long since gone to that great junk yard in the sky), I designed a circuit whereby plugging in the heater lit a lamp. Whole thing was in an outdoor electrical case. Bulb blinked which attracted my attention either before I got in or in drivers seat looking out. Bulb gave positive proof that heater was electrically functioning.
     
  16. pEEf

    pEEf Engineer - EV nut

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    Since I've got a PHEV conversion, I plug in every time I can anyway, so the plug-habit is near automatic. Plugging in powers the Block Heater, the PHEV Charger, and the 12v charger. Since the BMS knows I'm charging, I have it send CAN messages that cause the Red Triangle to appear if you start the car with it still plugged in.

    Anyway the point I want to make was once you get in the habit of plugging in every time you pull in, it's easy and you don't even notice the extra steps. If you are worried about "drive-off" and you can't come up with an acceptable auto-pull-out setup, then just make sure the cord runs in front of the driver's door or the car so you can't help but notice. Hanging a cord down from above makes a lot of sense, keeps it clean, dry and away from fumes, and then you don't have to bend over each time. If you drive off it simply pulls out, just make sure the car end is short enough so it doesn't drag on the ground.

    If you are creative, you can even use the cord like your "tennis ball" for parking alignment! =)
     
  17. jayman

    jayman Senior Member

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    If you live in a bitter cold climate like I do, the instinct to plug in and unplug is there

    Toyota appears to have gone to the non-immersion heater. My FJ also uses the one that fits into a machined recess in the aluminum block

    At 400 watts, not very effective at -40. Back in the good old days, with a V8 we'd stick a 400 or 600 watt frost plug heater on each side of the block.

    Worked great at -40, and if one frost plug heater quit, the other one still worked so at least you'd get started.
     
  18. pEEf

    pEEf Engineer - EV nut

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    After some careful experimentation, I've found this 36ohm heater can deliver more power for a fast heat. I generally plug into 240v when I'm charging my PHEV at home, so I built a circuit controlled by the BMS ECU to control power to heater. I don't recommend you connect it directly to 240v as it then becomes a 1600w heater, but there is room for more if you have some feedback as I do.

    I used a non zero-cross switching SSR controlled by a microcontroller that knows the line voltage and when zero-crossing is occurring. If it detects it's plugged into 240v it delivers up to about 1000w max and monitors the coolant temperature to regulate it to any setting I choose. Right now I'm not letting my engine run hardly at all on the PHEV, so this allows me to have some heat when I first get in the car. A warm car will hold it's heat surprisingly long, at least here in the mild winters we have.

    I put a 5a slow-blow fuse on it just in case something happens. The aluminum heater slides into a machined bore on the rear of the upper block, and it appears to be very close to the water jacket, so it's likely almost as effective as an immersion heater given the conduction of aluminum. I didn't use the generic silicone grease that came with it, instead I upgraded to a better silver-based compound.

    What would be better for me anyway is a in-line coolant heater that installs in my heater hose, then I could engage the pump when it's on. This would pre-heat both the engine, heater core and all the coolant.

    Anyone know of a decent one that's not crazy expensive? I imagine it would be easy to fabricate one, but why bother if it's cheap.
     
  19. Simtronic

    Simtronic Active Member

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    What would be better for me anyway is a in-line coolant heater that installs in my heater hose, then I could engage the pump when it's on. This would pre-heat both the engine, heater core and all the coolant.

    Anyone know of a decent one that's not crazy expensive? I imagine it would be easy to fabricate one, but why bother if it's cheap.[/QUOTE]

    Try one of these, pump thermostat and heater all in one.

    original hot frog universal Motorvorheizer pre heater
     
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