I have not had a chance to get through all my manuals, but maybe someone here knows the answers.

A. When do you use 'B'? I know its for keeping the car from over accelerating on downhills etc and it boost the charging of he battery pack. But can you also use it for normal slowing? Like when exiting onto an offramp? I know when I test drove the TCH the salesman said try not to use it over 50 MPH.

B. Does light braking use the conventional pads at all or is that only under hard braking?

 

I hate it when someone who doesn't have the vehicle answers the question, but honestly, I can answer both.

A. You can never use B if you don't want to. The NAH works by drive by wire, which means your shifter doesn't actually do anything but send a request to the PCM that you'd like to shift. N, D, and B are all physically the same, it's just a software change that determines how the vehicle operates. B is exactly the same as D, but anytime you let off the accelerator, automatic light braking/regen occurs. When coupled with the brakes, you can find your stopping "power" is increased. Many drivers shift to B when they know they'll be stopping up ahead, to increase the regen that they recapture at a stop, and because after a while, they turn into lazy brakers. There's an old saying," D to drive, B to brake", but it isn't really necessary to do, but is a technique that some drivers use religiously. You can do this at any time and at any speed. The TCH salesman was wrong. (Which is no surprise to most people here.) You can also use it to slow yourself if traffic ahead is slowing without touching the brakes where you need to lose a slight amount of speed for just a few moments, then shift back to D to resume cruising or accelerating. I myself shift often between D and B.

On a somewhat related note, when you shift into N, the state of the vehicle will remain so. So, if the ICE is off, shift into N, it will stay off. This is useful during the winter (assuming you have a cold winter), when you want the ICE to stay off, you can pop it into N, and it will stay off, no need to worry about the ICE popping on to reheat things until you're ready to drive away, be it from a stoplight or a Drive through window.

B. Yes and No. Light braking only uses regenerative braking above 7-10 MPH (The actual MPH will vary by model, so I'm not sure of the NAH's lower limit), below that speed, it's actual physical braking. Above that speed, the only time you'll use the physical brakes is when you slam suddenly or hard on them, the rest of the time, it's regen. This leads to the "problem" that after rainstorms or after long periods of non-use, the brakes will suddenly get grabby. They'll actually develop a layer of grime on them, which combined with the wetness, cause them to get very grabby when they're used. You can get rid of this by braking often, which will clean the brakes and dry them, shifting into N, which will disengage the regen braking and use friction braking, stopping, and allowing that single stop from speed to clean them, or just wait and they'll eventually clean themselves bit by bit at a time.

Welcome to GH, and Enjoy your NAH!

 

Actually, the previous poster was wrong. "B" stands for engine braking. Normally the brake pedal gives regenerative breaking except when almost at a stop. The problem comes with very long downgrades where the traction battery fully charges and the conventional brakes have to be used. Using B forces the ICE to absorb the energy (usually spinning with fuel off). It's a bit strange because if you step on the gas the engine slows down!

You can switch to B at any time, but shouldn't use it except on very long downgrades as the regenerative braking energy is reusable while the engine braking energy is lost. At least it saves the brake pads.

My understanding is that "N" is only there to meet legal requirements that there be a neutral "gear". In "N" if the ICE is running it can only spin the generator freely. Keeping the car in "N" will drain the traction battery since there is no way to recharge. If you are sitting for a long red light, keep in "D". The engine will only come on to keep the battery charged and the engine warm to meet emissions requirements.

 

Great info, especially on the brakes. thanks

I did hit the brakes pretty hard yesterday on the fwy and it felt like the brakes locked up for a quick second.

 

Hmmm... I looked it up, and it seems you're right. That's odd, it seems that the NAH/TCH version isn't a regen braking setting. Thanks for the info.

 

I have been putting my NAH in neutral to go through car washes. This is correct?

 

Yes, but you aren't inside the wash long enough to cause a problem.

 

To clarify this further - at least in the Toyota family of hybrids, which of course includes the Altima - when you let off the accelerator you DO get regen effect, but it is only mild, simulating what happens when you let off in a non-hybrid in "D" and there is mild engine braking.

If you routinely use "B" mode, you'll see a decrease in FE, as part of the braking energy is absorbed by the ICE as Talmy noted, rather than shunted to the battery by necessarily stronger regen braking.

Pete

 

Let's see if I'm taking away the correct conclusion then...if slowing down for something like an offramp I'm better off lightly braking for brakes generation.

 

Correct.

Pete