How do I use the battery info on the comsumption screen?

I don't know if I agree with the "green" cars as being bad either. For one, if they were to be avoided, why would the software engineers have put them in the program to tell you how much power you're re-generating through either engine braking or conventional braking. Granted you are wasting energy doing conventional braking, but with the hybrids at least you are recouping some of that wasted energy in the form of stored power. With a conventional vehicle that energy is totally lost. So be it a small amount of energy that is generated from braking, it is still beneficial, that is just that much more energy stored that the ICE doesn't have to generate ... but coasting (engine braking) is the most beneficial way to store energy in the batteries. Obviously, it would be nice to take that re-generated energy and immediately reuse it...but then we would attain something that is virtually impossible to attain, kenetic energy...so I disagree that getting the "green" cars should be viewed as bad...when I've looked at the consumption over the 5 min periods, the ones where I have more green cars in them seem to correlate to the higher MPG periods also...just my $0.02 worth...

Red

 

Maybe Evan's point is that one shouldn't make getting leaf cars a goal. Under non "downhill" conditions, the presence of leaf cars represents a possible hint that driving differently (if conditions allow) will decrease the total energy used to get the car for 'here' to 'there' since the recovery is not all that efficient.

 

<div class='quotetop'>QUOTE(efusco\";p=\"43901)</div>

PLEASE read my previous post. Green leaves are GOOD in the sense that some energy that otherwise would have been lost as heat has been regained. They are BAD in that they indicate lost kinetic energy. Ideally no loss of energy is BEST, clearly that's not achievable. Toyota has certainly done a great thing in creating the regenerative braking system allowing us to recapture some of the energy that would otherwise have been totally lost as heat. That is the obvious thing.

What is not so obvious is that the more leaves you see is an indirect measure of energy LOST as much as it is a direct measure of energy recapured. What ever can be done to minimize the energy lost (represented by fewer leaves) ultimately leads to even better efficiency.

Listen, we're splitting very fine hairs here. We're talking about a maximum 4% difference in fuel efficiency--probably less than 1 mpg. No matter if you coast (with regen) or glide, or if you brake hard maximizing the use of friction brakes and minimize use of regen. It's just not a whole lot either way. But we priites like to split those hairs as it gives us food for thought for future improvements.

My point in calling the leaves BAD is that using the accumulation of more leaves as an end or goal is not the best way to improve efficiency. Your goal should be to maximize anticipatory stops/slow downs, maximize gliding, and minimize the leaves if you really want to strive for the absolute best fuel economy.[/b][/quote]
:idea: Stated that way I agree with you...like you said, we Prii owners will start splitting hairs to find a way to squeeze more efficiency out of the vehicle. That's what make owning a Prius fun. I've found that my Prius driving habits have carried over to my driving my other vehicles...I coast as much as possible....

 

Hope I can be helpful:

Friction Braking < Regenerative Braking/Coasting < Regen-free Gliding

Naturally, concerns other than fuel efficiency, e.g., "not hitting that posse of nuns", is going to take priority, and we're all going to friction or regen brake regularly. All things being equal, though, I'd prefer a situation where I could glide silently past the convent.

Brad

 

<div class='quotetop'>QUOTE(TonyPSchaefer\";p=\"43889)</div>

Watt-hours seem to confuse many people. Watts are units of power, Watt-hours are units of energy.

Each leaf is 50Wh stored into the battery. In principle, this means 50W spread over one hour, but in practice is more power for a shorter time. For example 5kW for 0.01 hours (that's 36 seconds).

Perhaps one way of thinking of it is if you have (or know someone who has) a coin-operated electricity meter. You need to insert a coin or token for (say) each unit (kilowatt-hour) you use. If you draw lots of electricity (lights, TV, heaters, etc all turned on), then you'll have to insert several coins in a day; if you turn everything off, you can go all day without paying the meter. The Prius is the other way around - using the brakes generates electricity, and you get tokens (leaves) out of it. Otherwise, imagine each leaf is a token, each five-minute block in the car is a day in your home. If you use the brakes a lot, you get a lot of leaves back in five minutes, just as if you use all your appliances, you put several tokens in the meter; if you use them sparingly, you'll get none, just as if you turn your appliances off, you don't need to feed the meter. Either way, one leaf is one-twentieth of a unit of electricity.

Prius doesn't tell you told how much power is being recovered and for how long - just the total energy recovered in the five-minute period. In practice, the power varies from moment to moment - the mathematical technique of adding it all up is the branch of the differential calculus called integration.

BTW, I presume you know this only applies to energy recovered by braking - energy transferred directly to the battery from the engine (for example, if you're parked during warm-up) isn't counted.