chaitov52

Thanks to whomever wrote about using the B-mode when coming to a stop to accelerate the charge-up of the battery (I put it back in D-mode for driving). I tried it for the first time yesterday and within two major stops, the battery was fully charged for the first time since I've had the car, which is 4 days now, and it stayed fully charged with regular driving after that before I got to my home community (about 10 minutes driving).

I live in a rather large gated community and our speed limit is 25 mph. Yesterday was the first time I've been able to drive the entire way home on electric power within our community.

This forum is the best library of knowledge, in my opinion, to get the most out of your hybrid. I can't help it, but thanks again to all of you who take the time to share your experiences.

Cheers

Nextourer

Not sure how "B" mode charges up the battery faster (unless it's < 22mph at which point engaging B provides maximum elec. motor resistance for regenerating) but glad it's working out for you!

chaitov52

Can't remember where I found this recommendation on the forum but the member who mentioned doing this implied it had something to do with more resistance for regenerating as you suggest. I tried it again yesterday to see if it had been a fluke and it fully charged up the battery on the first attempt. I only engage B-mode when coming to a "fast" stop from a higher speed. Doesn't seem to "do anything" when I'm just cruising down from 30 mph.

BobBass

Interesting article on 400h engine braking (or lack thereof unless "forced" - which is what you would want on a hybrid, after all) from Edmunds:
http://blogs.edmunds.com/roadtests/1115

Nextourer

Yeah so I did what you did coming down the mountain today and shifted into B. My Prius engine braked like it was supposed to but after a while, my battery turned green (7 bars). Was expecting engine braking only but apparently it also was regenerating a bit.

Note that using the brake pedal will regenerate more power, faster because it'll create more resistance using the elec. motor. Of course with the brake pedal method, you're gonna have to do quite a bit of experimenting in finding the maximum brake pedal pressure you can apply before the friction brakes engage. I think it might be easier for you guys since you have that "tach" that goes in the blue EV zone.

iKenn

iTrader: (1)

i dont get it, so B makes its brake easier? or it forces the battery to charge?

chaitov52

What I'm experiencing is that I think it forces the battery to charge quicker through the braking process. Again, I read this somewhere on the forum but don't remember where I read it, but it seems to be working for me.

I am getting the same consistent results, meaning daily, where I find that my battery indicator fills up and the bars turn light green after one or two or three times putting the trans into B-mode. If I have been driving on electric power alone, it usually takes two to three times to replenish the batteries. But so far, I have not had to go more than three shifts into B-mode to get the "green bar" effect on the battery indicator.

Hope this clarifies things a little bit better.

Edit: I just found the thread by VS2 from Auckland where the B-mode was mentioned about sending the power gauge into the blue area. That's where I got the idea for charging up my battery. Thanks VS2!

mindmachin

I don't know where in the manual it explains this, but B mode should actually decrease the speed of battery replenishment (charging). It is actually less effecient than using your breaks to stop.

B mode engages the transmission so that the gas engine will help breaking and thus you will get less recharging. The manual says the B mode should only be used to help slow you like say in the mountains where there are long downhill stretches so you don't overheat your breaks.

I have a Toyota Prius and a Lexus RX 400h and I have been able to verify this in the mountains on vacation trips I have taken.

In the RX and Prius, the car is set up to coast freely before you apply the breaks, the engine is actually disengaged by the CVT, when you break to slow down you engage the dynamic breaking which activated the electric motor and makes it act like a generator to help apply resistance and thus slow the car. The harder you push the pedal down the more the motor/generator produces larger amounts of electricity. When you change to B mode, the gas engine helps breaking and thus you loose some energy that breaking would have generated.

Hope this helps you guys.

Nextourer

That sounds right to me, or at least what I know is the function of "B".

Max braking comes with the brake pedal (up to 100amps for the Prius). B engages engine braking and I suppose has a bit of dynamic braking too. It's just so that you can keep the car at a constant speed (or slow down) while stretching the battery (so to speak). If you were to brake, you'd charge up the battery faster and thus will have to switch to friction braking sooner.


I've rarely used "B" and my brake pads are 90% front and 95% rear life left and this is 90% city driving not highway driving so I am braking a lot.

chaitov52

Cheers

iMSQ

https://www.clublexus.com/forums/hyb...l#post11112742