Battery not charging fully when driving?

The gasoline engine won't fill it, but downhill regenerative braking will fill it.

 

I have not encountered a hill to test this. In the coming weeks, perhaps I will and then I will be able to see if that happens. However, in the month I've had my Prius, I have not.

 

If your battery's typically around 50% that seems a bit low, at least: ours is usually around 75%. Maybe it just varies, but my hunch is you're pursuing ev a bit too aggressively.

If ours is around 50% it's usually on its way down, or climbing back. It's not typical status quo.

 

I agree with Mendel's post #23.

Bisco, what I meant about "mostly" normal was that the 50% claim wasn't quite normal, as Mendel and others have elaborated.

My state-of-charge display spends roughly 90% of its time showing six bars, only going higher on large downhills, and only going lower when the engine is not running. I was initially surprised it didn't drop below six bars on large uphills, but it doesn't, as long as the engine is running.

 

mine will also fill on the highway, under the right conditions, no braking.

 

nice.

 

yes, you're supposed to not use ev mode when hypermiling.

 

ya, there are some speeds where ev is hard to avoid. thats where pulse and glide comes in.

 

yes, accelerate moderately, (slightly right of the mid line on the hsi) then release pedal and apply enough pressure so that you're gliding (no ev or regen) it's hard to glide, so a little ev just right of the line is fine.

you have to be in an area where you can pulse a little higher than the speed limit, and glide to a little lower, without driving the guy behind you crazy. rinse and repeat.

 

It's easier to control pulse and glide if you select "eco mode". The modes mostly just modify the throttle response rate, and "eco mode" gives the largest throttle pedal movement at lower power.

I don't think there is anything wrong with your car. If you want to maximize fuel efficiency (it's a hobby) it takes lots of practice.
I don't think you should concentrate so much on that just yet. First get used to the car, and how it reacts to what you do. Read some of the things on this and other forums on the use of pulse and glide and try some of them out. It's not rocket science, you'll get used to doing it all the time and your mileage will improve to the 60s range when you get good at it. Much lower in winter, of course.

 

One thing I've noticed: driving with car warmed up, roads relatively level, lower city speeds, if you set Cruise Control: the car will happily stay in EV, keeping the HSI (bar indicator) to the left of median, but right up to the threshold, as long a possible.

If there's no interruptions, it'll quickly run the state of charge right down to two bars remaining, no qualms.

 

Nothing in the propulsion system changes. Those mode buttons change only the user interface (throttle mapping of the gas pedal), plus some relatively minor tweaks to the AC and cruise control function.

So, it is just you, and how you relate to that user interface (i.e. gas pedal). The choice boils down to personal preference more than anything else. Clumsy people like me should usually get a bit better mpg in ECO, while people with the best coordination and dexterity should be able to get the same mpg in every mode.

The way the mode buttons relate to your foot on the pedal should change MPG by somewhere between zero and a few mpg, in either direction, depending on your particular driving style. The large change you witnessed was caused by something else.

Is your workplace at a different elevation than your home? That can make a big difference. Did wind or weather change? Did traffic density or behavior change?

Tomorrow, reverse the pattern, use ECO to work and Normal to home. See if the pattern stays the same or inverts. After that, use the same mode for full round trips, but change modes for different days.

 

ECO mode adjusts the throttle response, among other things, so it will feel more sluggish. However, I doubt that was the "sole" reason for the mpg difference. I can get 70+ coming back from the library (about 7 miles), but only get high 40's/low 50's going, and that's with the ICE already warm. The next trip, similar traffic pattern, I won't came close to 70. The best way to compare is to drive it R/T in both modes for several days each and average the mpg. Even then there might be unseen factors at play, longer time to get up to speed, longer stop at traffic lights, less coasting time, etc., any number of things, especially on short trips.

 

If you push the accelerator appropriately farther down in "ECO," then "pick up," fuel consumption, and what the HSI indicator bar shows will be all exactly the same. The main difference is that "ECO" makes it easier to fine-tune light acceleration. You also get to exercise your leg muscles a little more, to achieve the same results.