Is driving too lean hard on the battery?

If by "too lean" means that you're accelerating so lightly that you're trying to accelerate in EV only (ICE off), that's not the most efficient way to drive anyway. For efficiency, you want to minimize battery use, both in and out.

As for new traction battery, did it fail and get replaced under warranty? What were the symptoms and DTCs? Where's WahWahi? Is it in Hawaii? If so, for longevity, I'd suggest you try to keep the car's interior temperature down (when possible) by parking in a garage or carport, in the shade, putting up a sun shade, etc.

 

wait, what? new battery? wahwahi? hawaii? did i miss something?

 

if you do a little searching and reading on improving mpg, you should be able to get up to 55-65 if you're so inclined. and no, you cannot reduce the life of the battery no matter how you drive.

 

Hi jmooney. Technically yes, the more you "cycle" the battery then the faster it will age. In practice however I don't think the type of driving you describe would impact on battery life very much. It's more like hard driving in mountainous terrain and at high temperatures that are likely to stress the battery and shorten it's useful life.

Battery wear and tear aside, try to judge your fuel efficiency over a full tank when making comparisons. Yes you'll easily increase your instantaneous MPG's by running in electric only mode, but eventually the engine has to cut in and then work harder to recharge the battery with the overall result often being poorer fuel efficiency.

Hyper-milers will do that trick (coax it to stay in all electric mode and allow the battery charge to run down) when there is an opportunity to recharge for free, typically when a good long downhill immediately follows. On flat roads however you're generally better not to try and coax it too much (it will still go all electric when it wants to) and thus avoid the charge dropping too low.

 

Theoretically the shorter the range of battery used, the longer the battery life.

The best mpg is obtained by using the battery as little as possible. The Prius gets it's good mpg mainly because the engine is sized for steady state driving rather than acceleration. The electric motors are there primarily to provide power for additional acceleration. They also allow the engine to be turned off when the power demand is so low that even the efficient Atkinson cycle engine would be inefficient.

Every time you use the battery you go through an additional energy conversion loss.

The best way is to treat the battery like a credit card: Used sparingly a credit card can even out the month's cash flow. Used too much and you won't be able to pay it back and will get high interest fees.

My 2004 Prius has a lifetime average of 57 mpg over 115,000 miles.

 

First you're not driving "lean". This refers to the air-fuel ratio in the engine, and you're not controlling that by driving more efficiently. You're controlling use of the engine in high load situations and minimizing loss through braking.

Second, I doubt anyone could show facts that indicate the traction battery life can be influenced by how you drive, short of running out of fuel. The level of charge in the battery has nothing to do with its' service life. It's a NiMH battery, and can be left at any charge level indefinitely with no effect on its' life.

So go ahead and drive in the most efficient way you can. The HSD will take care of the battery for you.

 

For best fuel economy, accelerate briskly from a stop, but otherwise drive as if you have no brakes (but not so much that other drivers will want to kill you, of course).

By The Way, if you don't have the owner's manual, get one from a dealer or online. It's full of stuff you need to know.

 

The system is designed in a way the computer will protect the battery. It will not allow the battery to drop below a certain point as well as above a certain point. So really I don't think you can do any damage just by the way you drive the car. So, I say drive it the way you want to drive it.