B - Mode Noise!

if the battery is full, the engine revs up like a jake brake..it's spinning without fuel. when the battery isn't full, the electric motors spin up to charge along with the engine. so it revs but quietly.

all it's doing is pulling air since the drag of having to pull air without fuel slows the vehicle. keeps it maintainable anyways.

 

Correct, mostly. Remember when you use B-Mode you are requesting engine braking whether you need it or not. One way you can tell you are using engine braking is if the engine gets quieter when you step on the gas. Stepping on the gas calls for more speed, so the control system reduces the drag from the ICE by spinning it slower.

Tom

 

Right, although you might want to check on those cards in your spokes.

Tom

 

The official Harley sound, as written in a legal filing by Harley, is "potato, potato, potato..."

Tom

 

Yes, normal. You should use "B" on a long downgrade, when needed to save the brakes, without regard to the state of charge of the battery. The car will manage the battery by itself.

 

Yes. (For the occasions I have descended the Blue Ridge.)

A little technical background: A "full" battery as shown by eight green bars is not exactly full. The car babies the battery to avoid over-charging and over-discharging. The MFD battery display actually reflects a range from 40% to 80%+ charge:



So the eighth green bar may light with as little as 75% SOC, though it has room for a little more charge. Then as the 80% threshold is reached (and occasionally exceeded -- I have seen it as high as 82% with CAN-View), the car stops accepting more regeneration and instead becomes more aggressive in trying to reduce SOC. This includes using one of the motor/generators to spin the ICE at a higher RPM during coasting -- undoubtedly what you hear as "roaring." It also includes, incidentally, an increased tendency to use only electricity when propulsion is needed. It's a paradox of sorts: ICE RPM goes up when you let off the gas pedal, and the ICE shuts down when you step on it.

I'm surprised no one has linked this article yet. It's a good discussion of how B mode works.

Another item worthy of mention. If SOC tops 80%, the car itself will intervene regardless of whether you're in B mode. See this for the observations of several of us who have seen B-like behavior while in D.

 

This is my experience as well. You have a little more room for charge even after all the bars are green.

Tom