Quote:
Originally Posted by Mark E Smith
Is the battery heater componet of the Ford block heater system worth it? Does it allow better regen when the temps drop? Lately with morning temps in the 40s I have noticed a lower regen and battery useage. Is this a function of battery temp or outside air temp?
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Now that I've had the "whole" system... IMHO the HV
battery heater is
THE MOST IMPORTANT PIECE of the system.
CAT temp. turns out to be irrelevant 99% of the time.
MIN. CAT temp to "scrub" the exhaust is ~750 degrees F.
The CAT runs at 1300-1500 degrees F.
The CAT cools at about 1'F per second with ICE off.
So you have about 600-720 seconds.... 10 to 12 minutes of EV before the CAT kicks the engine back on for heat.
Other things effect EV sooner.
CHT ( cylinder head temp ) is the parameter that allows / disallows EV most of the time. This value cools off quickly ( couple minutes ) when it is cold outside... quicker yet if you run the heater, and you lose a tremendous amount of heat in the heater core to the cabin. While this parameter kicks the ICE on and off, it heats up pretty quick also ( just a few minutes for initial warm-up... 1 or 2 minutes each time after initial warm up ).
The HV battery temp does not allow / disallow EV ( unless it is hotter than 100'F and forces A/C cooling to be on ). You can get EV at zero degrees F. However, if the battery pack is very cold, it will reduce, or disallow rengen to enter the pack. If it is cold, it will not allow many amps out of the pack, so you won't get EV launch from stops. I found in my 2005, the ICE will kick off at zero degrees, and the car will sit still at stops in EV, but you can't get much driving done in EV.
So why do I think the HV battery warmer is so important? #1 important in fact? Because it is the
SLOWEST to warm up on a cold day. If all three parts are cold, you will warm the CAT from gasoline in 30-60 seconds. You will warm the CHT from gasoline in 5 minutes. You cannot (really) heat the battery with gasoline! Therfore, I believe the most benefit comes from having a warm battery from a plug-in heater.
When I start my day ( today in fact ) at +3'F, my battery was 64'F and allowed full regen, and full assist on my A.M. commute... which is only 15 minutes. If the battery started at +3'F, it would not have made it up to the freeze mark in those 15 minutes.
The battery gets warm quickly even on frigid days, since it is protected from wind, and is in a confined space. ( only 75w too )
My Block temp only made it to 50'F this A.M. with a 400w heater since it is external, and not protected from the breeze.
Starting with a block temp warm gets you EV 2-3 minutes quicker.
Starting with a warm battery does not get you to what I'll coin "static" EV any quicker, but it gets you usable EV ( regen and launch ) from the get go, vs. maybe 20-30 minutes later, on a zero degree F day.
That is what I have observed the past 3 months.
This is the first season I've had the block heater / battery heat.
I think the most utility EV wise comes from the battery heater.
( but EV aside, it's nice to have 50'F oil and water from the key turn also... for both the engine's sake, and quick defrost... you don't have to run gas in the driveway to "warm up" the car to melt the frost, etc. )
P.S. on a 40 degree morning, you can have 100 degree water, and 75 degree battery. The battery heater might cycle, the block heater is always on.
-John
Battery heater componet
