Why this behavior?
#1
08-09-2007, 07:37 AM
Why this behavior?
Yesterday, I filled up my HCHII and while waiting for my wife to come out of the HandyMart, I tried this experiment.
I had 3 bars of charge on the traction battery, so I started the engine, and revved it to 3000 rpm in neutral... It did not produce any charging of the traction battery . I am surprised it didn't, and can't think of any good reason not to regen in neutral.
Then I tried the same thing except with the tranny in park. This time it did produce a charge, but only 3 or 4 green bars. Why wouldn't it use the opportunity to produce max charge?
Third experiment. I revved the engine to 3000 rpm, and holding the throttle steady, I turned on the AC. When the AC compressor kicked in, the rpm dropped to 1800. Wow, I was surprised at how much power it really takes to run the AC.
One other time, I tried revving the engine in neutral to red line, but the engine cuts out around 4200 rpm. It must be programmed to limit the rpms. I know the engine will rev higher than that though, because I live at the top of a 4 mile 7% grade, and to make it up the hill at 55 mph, the engine usually revs above 4500 rpm.
This car is full of surprises.
I had 3 bars of charge on the traction battery, so I started the engine, and revved it to 3000 rpm in neutral... It did not produce any charging of the traction battery . I am surprised it didn't, and can't think of any good reason not to regen in neutral.
Then I tried the same thing except with the tranny in park. This time it did produce a charge, but only 3 or 4 green bars. Why wouldn't it use the opportunity to produce max charge?
Third experiment. I revved the engine to 3000 rpm, and holding the throttle steady, I turned on the AC. When the AC compressor kicked in, the rpm dropped to 1800. Wow, I was surprised at how much power it really takes to run the AC.
One other time, I tried revving the engine in neutral to red line, but the engine cuts out around 4200 rpm. It must be programmed to limit the rpms. I know the engine will rev higher than that though, because I live at the top of a 4 mile 7% grade, and to make it up the hill at 55 mph, the engine usually revs above 4500 rpm.
This car is full of surprises.
#2
08-09-2007, 10:04 PM
Ridiculously Active Enthusiast
Join Date: Jul 2007
Location: San Diego, CA, USA
Posts: 941
Re: Why this behavior?
I am surprised it didn't, and can't think of any good reason not to regen in neutral.
This time it did produce a charge, but only 3 or 4 green bars. Why wouldn't it use the opportunity to produce max charge?
Wow, I was surprised at how much power it really takes to run the AC.
I live at the top of a 4 mile 7% grade, and to make it up the hill at 55 mph, the engine usually revs above 4500 rpm.
#3
08-10-2007, 07:16 AM
Pretty Darn Active Enthusiast
Join Date: Feb 2005
Location: Northern California
Posts: 387
Re: Why this behavior?
Yesterday, I filled up my HCHII and while waiting for my wife to come out of the HandyMart, I tried this experiment.
I had 3 bars of charge on the traction battery, so I started the engine, and revved it to 3000 rpm in neutral... It did not produce any charging of the traction battery . I am surprised it didn't, and can't think of any good reason not to regen in neutral.
Then I tried the same thing except with the tranny in park. This time it did produce a charge, but only 3 or 4 green bars. Why wouldn't it use the opportunity to produce max charge?
I had 3 bars of charge on the traction battery, so I started the engine, and revved it to 3000 rpm in neutral... It did not produce any charging of the traction battery . I am surprised it didn't, and can't think of any good reason not to regen in neutral.
Then I tried the same thing except with the tranny in park. This time it did produce a charge, but only 3 or 4 green bars. Why wouldn't it use the opportunity to produce max charge?
One other time, I tried revving the engine in neutral to red line, but the engine cuts out around 4200 rpm. It must be programmed to limit the rpms. I know the engine will rev higher than that though, because I live at the top of a 4 mile 7% grade, and to make it up the hill at 55 mph, the engine usually revs above 4500 rpm.
This car is full of surprises.
#4
08-10-2007, 07:33 AM
Re: Why this behavior?
This was an interesting experiment, but actually driving the car in forced regen is a more efficient way to charge the battery than revving in Park (a nearly complete waste of gas actually!)
I've tried running my A/C while going uphill before and noticed the utter drop in power. That's why I always turn off my A/C while going uphill, and try to avoid using it altogehter (open the windows in city driving, close the windows and open the ventilation fan on high speed on the freeway, wear light (both weight and color) clothes to keep cool in summer)
I don't know the rev limiter cut in so early, but revving the engine so high in neutral is not good for the life of the engine. I'm also surprised you get 45 mpg with those kind of RPMs; I only need 3000 RPMs to get my up my hill, at 35 mph. Perhaps you could try lowering your speed a bit? Unless the posted speed limit is 55 and the people following are impatient.
This car is full of surprises.
I've tried running my A/C while going uphill before and noticed the utter drop in power. That's why I always turn off my A/C while going uphill, and try to avoid using it altogehter (open the windows in city driving, close the windows and open the ventilation fan on high speed on the freeway, wear light (both weight and color) clothes to keep cool in summer)
I don't know the rev limiter cut in so early, but revving the engine so high in neutral is not good for the life of the engine. I'm also surprised you get 45 mpg with those kind of RPMs; I only need 3000 RPMs to get my up my hill, at 35 mph. Perhaps you could try lowering your speed a bit? Unless the posted speed limit is 55 and the people following are impatient.
This car is full of surprises.
Thread
Topic Starter
Forum
Replies
Last Post
tbaleno
Off Topic
13
08-29-2009 09:41 PM
