Why the battery doesn't charge 100%?

6 bars is pretty normal for regular driving. You may occasionally see 7 bars. The only time you should expect to see 8 bars is when you're doing a lot of downhill driving with corresponding regenerative charging. The system maintains that partial "empty space" to allow for just that scenario. Relax and enjoy, its all good. 2 bars to 6 bars is the normal range.

Actually you should hope to see lower levels much of the time, because that means you're using that "free" energy instead of just storing it.

 

And don't freak out if you are parked running the A/C for a while, burn your bars down to 1 or 2 and pull onto a street...

When that happens, the electric motor is DOA until it recharges up to I think 3 or 4 bars...until then, you have a car powered only by what seems to be a lawnmower engine.

 

it tries to leave room for more regen when going doenhill etc. so it uses enough battery under normal circumstances to keep it a little above half and improve your mpg's.

 

Thanks for the question. My husband was just wondering the same. He is driving our 2008 GenII and that battery indicator is often at full bars, so when he got in the v with me he was asking me why the indicator in the v never showed full. Now I can supply an answer the next time he asks. Except I'm left wondering about the difference between the two cars.. (Or is it driving style? He is averaging 48.7 in the GenII and I am getting 46.7 in the v, which is well above my expectations for the v.)

 

Might just be a difference in the way the display indicator works.

 

08 should not be showing full bars most of the time, unless he's doing a lot of downhill driving. but in that case, you usually have to come back up at some point!

 

Driving style and conditions make a big difference in these cars. Maybe you two could swap cars for a tank or two and see what happens.

 

My understanding is that it's a design feature. The traction battery lasts so long because it is never fully charged or discharged. The car's computer sees to that.
In addition to my V, which I've had for 3 months, I have a generation 1 Prius (2002) that has about 115,000 miles on it. I am the original owner, so I know for certain that the traction battery has never been replaced. The only time I can recall ever seeing the battery indicator on the '02 show a full charge was once while driving down very long mountain roads in Colorado.

 

I think the owners' manual says something about protecting the battery by not letting it charge to max.
So it's normal to almost never have the top bar.

 

OK, good info, so I need to drive his car and see what is happening with the batter indicator.

 

Yes. For this sort of battery, the best longevity occurs when the average charge level is somewhere near the middle. That is one reason why these sorts of batteries are shipped from the factory with a partial charge.

(Of course, another reason for the partial factory charge is that a full charge takes too long on the production line.)

 

Actually a full set of bars is only about 80% capacity. Charging a battery gets inefficient as you approach 100% both wasting energy and generating heat which reduces battery life so Toyota wisely chooses to generally limit charging to 80%.

JeffD

 

Ah, ha. Mystery solved. My husband was looking at the battery indicator in the "v" and thought it was the fuel consumption graph that he keeps on the screen in the hatchback. He keeps that at 100 mpg so much of the time, that he wondered why I wasn't doing the same--lol! Once I explained that was the battery indicator, riddle solved.