B - Mode Noise!

[Whiteyprius]

I took a great big Smoky Mountain Trip today. There were several times when I had downhill grades 2, 3, or 5 miles long. I used B - Mode, after maxing out the battery bars - But today, the first time I dropped into B (at maybe 45 - 50 mph) it sounded like the 'ol baseball cards on the bicycle spokes to produce a motor sound trick. I've never had this kind of clattering before, even when using it at 70 or 75 on long interstate grades. Any idea? Is this something to be checked out at the Toyota dealer? I would appreciate any help!

[V8Cobrakid]

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.

[Whiteyprius]

Originally Posted by V8Cobrakid

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.

So let me get this straight - When it makes noise (and going a sufficient speed to create said noise) the battery is in fact full, and using B-mode was appropriate (to save conventional brakes). If at the same speed, it does NOT make noise, then the battery probably wasn't actually full, and I shouldn't have used B-Mode quite yet - Right?

[qbee42]

Originally Posted by Whiteyprius

So let me get this straight - When it makes noise (and going a sufficient speed to create said noise) the battery is in fact full, and using B-mode was appropriate (to save conventional brakes). If at the same speed, it does NOT make noise, then the battery probably wasn't actually full, and I shouldn't have used B-Mode quite yet - Right?

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

[Whiteyprius]

Originally Posted by Whiteyprius

So let me get this straight - When it makes noise (and going a sufficient speed to create said noise) the battery is in fact full, and using B-mode was appropriate (to save conventional brakes). If at the same speed, it does NOT make noise, then the battery probably wasn't actually full, and I shouldn't have used B-Mode quite yet - Right?

Originally Posted by qbee42

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

Bottom line then - This noise I heard was normal, and there seems to be NO malfunction - Right?

[qbee42]

Originally Posted by Whiteyprius

Bottom line then - This noise I heard was normal, and there seems to be NO malfunction - Right?

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

Tom

[Whiteyprius]

Originally Posted by qbee42

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

Tom

Balloons on your spokes make your bike sound like a Harley - but they don't last long! Thanks for your help!

[qbee42]

Originally Posted by Whiteyprius

Balloons on your spokes make your bike sound like a Harley - but they don't last long! Thanks for your help!

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

Tom

[richard schumacher]

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.