Question on engine + motor + battery
 

I'm not sure exactly how to phrase this since I'm new to the TCH (got mine Sept 26) and I'm still learning the lingo (still dont know what ICE means).

Today I was driving in heavy traffic. The battery/electric motor was being used 90% of the time. The only times the engine kicked on was when I was going uphill, or accelerated a little heavier.

Anyways, my battery was going down to a low level - 2 bars left. I was checking my energy screen and noticed something I found a little interesting and wanted to get your input on:

The engine kicked in so it showed arrows going from the engine to the wheels. But there was also an arrow from the engine going to the electric motor. What I found interesting was there was arrows going from the electric motor to both the wheels and the battery. I know when the engine is stopped and you're coasting, the momentum of the vehicle turns the electric motor (changing it into a generator) and charges the battery. But how can the electric motor turn the wheels and charge the battery at the same time? It seems that in my case above, the engine is turning an alternator which then provides power to the electric motor and also charges the battery at the same time. Any thoughts?

Oh and one more question.. occasionally I notice that when coasting, the analog mpg meter drops to 60mpg (not in the E mode), however the energy screen shows that the engine is off and the batter is being recharged -- Huh?

Re: Question on engine + motor + battery
 

ICE = Internal combustion engine. In other words, the gasoline motor. Took me a few days to figure it out also. :)

Re: Question on engine + motor + battery
 

Toyota Hybrid system has 2 electric motors/generators. Each one can generate electricity on it's own. One generator is coupled with front wheels and will either generate electricity or help pushing the car, depending on power demand, as long as the wheels are in motion and above some minimal speed this can charge battery regardless of Internal Combustion Engine. Another one is attached to transaxle and therefore to ICE, this one is responsibble for splitting output from engine between the wheels and itself. Since each generator is independent, one can act as electric motor pushing the car, another one can act as generator and charge batteries.
Up to 42 mph the gas engine can be off, above that speed the engine has to be spinning, because if it wasn't the electric motor coupled to it would need to spin above it's maximum 10,000 RPM. The fact the ICE is spinning doesn't mean it has to be burning gas. Sometimes electric motor can keep engine spinning without burning any gas at all. You can read more how the whole system works at Toyota site but I don't have the links handy. You can find list of all acronyms used here at the top of the page, under "glossary" menu.

Re: Question on engine + motor + battery
 

Hey, Pete, it sounds like you know your stuff on Toyota's Hybrid Synergy Drive. BTW, the site you may have been referring to has the following URL

http://www.hybridsynergydrive.com

I found this site this morning doing a Google search for "Hybrid Synergy Drive". Apparently, there are several hybrid technologies, and Toyota believes that theirs (no surprise) is the best. I plan to spend some time studying the site to see if there is more detailed information on how the technology works.

Re: Question on engine + motor + battery
 

Chris,

I should have given my answer to your "coasting" question in my last post. Here goes.

"E" mode as I understand it means the electric motor only is supplying power to the wheels. When you are coasting (as you put it), generally you are regenerating the big battery. Since the instantaneous MPG guage needs to have some reading at this point, I guess the Toyota engineers figured the best place to have the needle was at 60 MPG. This of course is technically incorrect, since the momentary MPG in that state is infinite (as it is in E mode).

BTW, to some on this site, the term "coasting" means something a little different...I've seen people on this site discuss coasting as that state where nothing is happening while the car is moving...no ICE, no regen and no electric motor. I personally have not seen this state for very long when I drive. As you do, I consider coasting to be moving with no power input to the wheels. But "hypermilers" seek that state of energy Nirvana where nothingness occurs, since this is thought to increase FE even more than being in regen!! (Some say it also causes the car to spontaneously levitate, but this may be purely apochryphal!!) ;)

Re: Question on engine + motor + battery
 

wcmack: Thanks for the link. Very interesting and it answers alot of my questions about synergy drive.

Re: Question on engine + motor + battery
 

Yes, thanks for the link, wcmack. It has a lot of info about the HSD. Thanks for the info regarding "coasting" as well. :D