Is there room to charge a "full" battery?

perhaps toyota has provided extra space for immediate regen, even with a fully charged battery, so the ice doesn't come on like it does on the pip.

 

yep, both

 

good question, don't know ... I have my 15k service coming up next week, after that I'll plug my carista in again, and I have this obdii fusion app that should give me some idea whats going on

 

Engine for sure does not come on for me. It would be obvious as it would need to go through the warm up cycle which takes a while. Range goes up a little but not very much and charge level shows 100% after the downhill. I think it's pretty clear there is a slight buffer at "100%"...

 

I have a downhill run pretty soon after leaving the house on a full charge. I can see a couple of miles gained in the EV range by time I hit the bottom of the hill. It definitely goes up so after a couple of miles of driving I am at a projected distance of a couple of miles more than what I started at. A nice bonus but it gets paid back when returning home. I need more than a couple miles left to not run out on that climb.
Damn gravity, it's not just a good idea, it's the law.

No idea if the ICE comes on at all during this time. I have not specifically noticed it but can't say for sure it hasn't.

 

To add to this, the state of charge (SOC, on my ScanGaugeII in the picture below) is 83% for a full charge. (fWT is the coolant temp. not the air temp)

 

Only slightly off-topic (and not worth a new thread)... you know the battery icon display in the MFD? The amount of EV charge left (over the buffer) is normally in green, and the amount of charge left in the buffer is blue?

Well there was one time where I had depleted the EV range completely (so only the "blue" below-the-bufferline was left). But then I went down a long, steep hill (in HV Mode), and the car started to recharge the EV range a bit on its own (rather than plugging it in or using the "charge" mode). And unless I was hallucinating, as the traction battery got charged a bit this way above the buffer line, instead of being the normal "green" for that part of the icon graph, it was suddenly a different color (Was it yellow? I can't remember, but remember it not being the normal green). Has anyone else seen this happen? If you're still in EV (thus, have "green" left) any additional charging will just add on to the green. But I was in HV mode at the time (because EV had run out) yet because of this really long hill, even in HV mode, the car had recharged some of its EV range back from zero on its own, and I could swear that instead of being green the icon graph showing the charge above the bufferline was a different color. Anyone else notice this?

 

It happened to me once. EV was depleted and I was in HV mode when someone needed to get in front of me real fast and then hit their brakes. After calming down, I looked at the EV indicator and it showed .2 miles left. Only time it has happened.

 

Full battery and you start out down hill. Trying putting it in neutral it will roll forever with no load and not charge the battery. I use to do this on my 2011 Prius. Best mpg was 75.3mpg on a 30 mile trip. I would get off the express way (full charge) and had a couple mile down hill trip. So i would save my battery for the flat part of my trip.

 

I live at the top of a hill. 1/2 mile with a 300 foot drop. I can not get down the hill with a full charge without the engine coming on and going through a warm up cycle.
It would be useful to have a charge to 95% of useable setting in this scenario.
My wife claims to be able to het down the hill without the engine coming on, but I finally figured out that it was because she doesn't plug the car in when she returns home with it.
Thanks for the clue to drop into neutral going down the hill to keep the engine off. It kills fuel economy on short trips having a warm up cycle triggered.

 

I have a similar hill at the start of my commute from my home and the engine has never come on... I estimate that the battery will charge up to 4% over "100%". At some point the engine will come on though for engine braking to prevent overcharging. I would guess that you are very close to the edge of that. Also, make sure you are in "D" mode and not "B" mode. "B" mode will make the engine come on sooner if you are near fully charged and going down a hill... sounds like neutral may be your cure though. Best of luck!

 

I never liked the friction brake remedy as it causes wear that I don't need. My morning commute goes up 100 feet and then down 400 feet. The ICE kicks in just as I get near the bottom and stays on for its 3 minute warm-up. I found that by cancelling the charge 30 minutes before done, the indicator was still mostly reading 100% but there was enough head-room to not kick on the ICE. I wish the car had a "short charge" feature. I usually put my briefcase in the car about 30 minutes before I leave, so this seems to work out pretty well. I am curious if you are dropping 800 feet, how much does the "short charge" have to be. Also, for those in the know about these lithium batteries, am I impacting the battery life in any way by doing this. On one hand, the last few % of charge usually generates the most heat, on the other hand, does full cycling help the life?

 

Definitely not. The less your level of "full charge" the better.

I often charge to 80-85% of the Prime's already ~=85% full charge when I don't need maximum range.

 

Also, remember that the miles remaining on electric are just an estimate based on recent experience, temperature, or whatever else Toyota uses for its estimation formula.

In "Meter Customize" settings, under "HV System Indicator", you can customize the "EV Drive Monitor to show the percentage of battery left instead of the estimated distance. Not saying any of you should change this (see the example from the owner's manual below)... but I would guess that a mild downhill starting out would keep the percentage near 100, or slightly less... while the estimated distance could increase because those recent downhill miles will factor into the estimation formula...

 

Since stopping your charge 30 minutes early does the trick... (it both saves the planet with less electricity pulled from the grid and saves your car from wear and tear)

...if you ever don't want to go to your car ahead of time, you could set your timer to finish charging 30 minutes *after* the time you plan to leave, and just unplug it and go with the same results

 

As soon as the 3rd blue LED on the dash starts flashing (around 30 minutes before charging ends) if you put the prius in Not-Ready mode and read the Available EV range, than switch off the Not-Ready mode and stop charging, when you put it in Ready mode ( if you prime is like mine) you should see less 2 or 1 less EV mile-s available.
I'll have to try stopping the charge with 50 minutes left and see if the same thing happens.

The last 30 minutes of the charge cycle is a trickle charge. From the readout of one of the chargepoint level 2 chargers I've hooked up to the charge rate drops to around 1.1kw in trickle mode from around 3.3kw most of the other hour and half of the charge cycle.

The sad part is that the experts don't all agree on which formula of charging and discharging Lithium Batteries works best. You'd have to do your own research to get a better idea.
I do agree from what I've read and understand from reading mostly about prius and tesla, that stopping the charge early should not damage the prius or tesla lithium pack and is most likely beneficial to the life of the batteries...

 

I charge to 100% overnight and have a decent down hill each morning, have not ever seen ICE come on. I've also noticed I get a mile or two after that with no drop in charge %. Cant remember a time I went down without a full charge, so no idea how much it's regening. Will have to try that out.