EBH and PHEV

[miscrms]

I am thinking that an EBH could yield even better results on a PHEV converted Prius, does that make any sense? My thinking is that the warm up cycle takes a fixed amount of gas. That amount of gas is percentage wise much more significant the higher your effective mpg is.

Similarly, I am wondering if battery ventilation in hot climates while parked would provide a boost. I notice that even when temps here are in the 90s, I often can't get into EV mode as I leave work. I'm assuming it will be worse when it gets to be 115 next summer. I think the battery cools down pretty quickly with the AC on, but again this cool down period probably becomes more significant in a PHEV conversion.

Anybody have any data on this? Sorry if its been discussed, as you may imagine searching any combination of EBH and plug turns up a lot of threads

Rob

[benighted]

All the EBH does is make the first MPG bar taller.

[douglas001001]

Are you suggesting using the PHEV battery to power the EBH?

[FireEngineer]

It depends on how you drive your PHEV. If you try to stay in all electric and stay in the before Stage 1 state then the EBH will do you no good. If you let the car go through Stage 1 it will increase the first 5-10 minutes of ICE operation.

Wayne

[miscrms]

<div class='quotetop'>QUOTE(FireEngineer @ Sep 27 2007, 03:17 PM) [snapback]518654[/snapback]</div>

It depends on how you drive your PHEV. If you try to stay in all electric and stay in the before Stage 1 state then the EBH will do you no good. If you let the car go through Stage 1 it will increase the first 5-10 minutes of ICE operation.

Wayne
[/b]

Ok, guess I should have provided more specific siuation

My situation is 10 min / 7 mi commute (one way). First mile and last mile are city, middle 5 mile is 65mph freeway w/ rolling hills. In 10 min commute I usually see 25-30mpg first bar, and 55-60 mpg second bar. Average on first tank is at 50.1mpg with constant low AC (its still 90+ here). Based on recent comments by local treehggr on his success with EBH, I am assuming I can pick up some ground with an EBH as well by bringing up that first bar. My assumption is that once the PHEV conversion is done, now I will be getting 25-30 mpg for the first bar and 100+ on the second bar. Since I only get two bars in my commute, this could weigh my average down heavily. Since the second 100+ mpg bar will use very little fuel, the average mpg could quickly become dominated by the warmup cycle. Just curious if anyone has any real world data to back up or refute that hypothesis.

Thanks,
Rob

<div class='quotetop'>QUOTE(douglas001001 @ Sep 27 2007, 03:00 PM) [snapback]518643[/snapback]</div>

Are you suggesting using the PHEV battery to power the EBH?
[/b]

No nothing that fancy, although....

Rob

[FireEngineer]

Depending on the capacity of your PHEV conversion, take some side streets and don't even let the ICE come on.

Wayne

[Aces]

<div class='quotetop'>QUOTE(FireEngineer @ Sep 28 2007, 09:31 AM) [snapback]518959[/snapback]</div>

Depending on the capacity of your PHEV conversion, take some side streets and don't even let the ICE come on.

Wayne
[/b]

I'm with Wayne on this one. If you stay below 45mpg, you could run full electric, so the ICE would never come on in the first place. In this scenario, the EBH is just wasting electricity. And since the ICE never comes on, you are using no gasoline, just electricity (cleaner and cheaper)

Now if you want to drive your normal route, at hwy speeds, the ICE has to come on. So there would be some savings. Probably you'd be about 100mpg.

Where it should be interesting is a commute like this: drive slow speeds (less than 45 mph) for an extended period of time (say 20 minutes) at pure EV, then drive hwy speeds. If you used an EBH, would the engine have cooled down so much during the pure EV mode time, that the ICE would still need to warm up for "emissions stuff" (that's a "technical" term I like to use!) My guess is in this scenario, the EBH won't help.

I'd love to hear comments from others on this. I am basing my comments on reasoning out the physics involved. But I could have missed something.

[mrbigh]

The use of an EBH always will be beneficial, one way or another. Remember that we are approaching winter time, low temperatures are not the best for mechanical's. The ICE will come on like it or not, so better to have the lubricants in the engine above ODT. PHEV or not, we are trying to enhance the operation of the Prii for better performance and investing $50 and some scraped knuckles and few cents of electricity as necessary will not send any one to bankrupt after $23K plus initial investment in the car.

[miscrms]

<div class='quotetop'>QUOTE(mrbigh @ Sep 29 2007, 12:28 PM) [snapback]519076[/snapback]</div>

The use of an EBH always will be beneficial, one way or another. Remember that we are approaching winter time, low temperatures are not the best for mechanical's. The ICE will come on like it or not, so better to have the lubricants in the engine above ODT. PHEV or not, we are trying to enhance the operation of the Prii for better performance and investing $50 and some scraped knuckles and few cents of electricity as necessary will not send any one to bankrupt after $23K plus initial investment in the car.
[/b]

Fair enough

rob