Prius prime plugin battery functionality.

Don't really understand the question.
A small section of the overall traction battery pack is reserved for HV mode and starting the ICE. How it's being managed by the software is a trade secret.

 

It's a black box, again trade secret. My icon indicates the bottom 1/3 of the traction battery is HV mode; but the icon isn't programmed to show us the entire available capacity. Through testing, even though the battery icon indicates it's empty - it can still function. So there is a hidden reserve. we can't see. There's also a question; does the battery ECU rotate between the 3 individual packs within my main pack? If the software doesn't rotate usage, we'll find out when the packs start failing in 10 - 15 years from now.

 

On a Gen4 Prius Prime, Hybrid Assistants shows the Hybrid mode activates when the traction battery reaches 15%. Being a 8.8kWh battery, that's would mean 1.3kWh left in the traction battery. The Gen4 Prius has a 0.75kWh traction battery. Almost twice as big. Prime is also heavier because of its bigger traction battery. Although, the previous Prius NiMH traction battery was 1.3kWh battery, so that could also well be the reason for that 1.3 kWh reserve capacity in the Prime...

 

it's just one battery with no physical parameters. everything is controlled by software.
as the battery degrades, it comes off the top in ev miles, and hybrid mode stays the same.

 

Concurring: Unless something has changed recently, the traction battery has no physical partitions for hybrid vs EV mode. A hybrid "partition" and an EV "partition" are a figment of the hybrid software's and display system's imagination. When the charge level falls below a certain point, the system is forced into HV mode, using the gasoline engine to maintain the desired charge level. The only real way to use up the "HV" portion is to prevent the gasoline engine from running (say, by running out of gasoline) and continue to drain the battery, and if the battery is discharged beyond a certain point, special charging equipment that dealers have is required to reactivate the system.

 

I wonder if going up a long steep hill or pulling a trailer can also deplete the hybrid battery.

 

Yes and No, I've done it many times going through the Sierras. The traction battery software will protect itself, but your ICE mileage will go into the toilet - the software will rely heavily on the ICE. Again, you are unable to completely deplete the traction battery - car's software will prevent that.

 

I believe that if the ICE is unable to run (like being out of gas), that that is one of the few ways to actually deplete the traction battery to the point that special equipment is needed to revive it.

 

I believe you'll get a shut-down warning, then the car will shut-down. I reminder reading that someone tried that a few years ago. They put a couple of gallons of gas into it and it fired back up. Either that or they had to disconnect the aux. battery for a few minutes - to give the car amnesia, then restart.
I believe a healthy traction battery can only be discharge by sitting too long without activity, say 6 months - then it would require a traction battery charger to bring it back to a state, that it will start the ICE.

 

how about a/c on in neutral, have they licked that problem?

 

Yes. If the downhill drive is long enough, it could potentially get totally filled by regen.

Many things affect battery life to say it will but generally speaking the bigger the battery the more "abuse" it can take. Current battery tech has shown that A) time and B) temperatures are the biggest overall factors while heavy use (charge/discharge cycles) affect individual cases.

PHEV designs are now over a decade old and yes they've lost range but it's in percentages.

Summation: Just drive it.

 

Yes, it will charge pass that 1.3 kWh and bring back the car into EV mode.

However, if you stay in Hybrid mode when there are EV juice left, I've noticed that the battery will get used but, not by much. When going to the cottage, after a one km city drive, we get to the highway for 30 km. During that time, I take it off EV and it does uses some of the EV battery, maybe a few km, not more. Which is what I wanted anyway since once I leave the highway and get on regional roads, I switch back to EV if the road speed is 80 km/h or less. I get to the cottage with a few km left in EV. My average consumption is around 3.2L/100 km for that trip. Although I prefer to take the Model 3 to go to the cottage, it's 0L/100 km

 

Yes and No; The software doesn't allow you to see everything, but being a larger battery - it can "hide" the degradation better than a smaller hybrid only battery. As our plug-in ages, we'll probably notice a very slow decline in EV distance traveled per charge and sooner engagement of the ICE. I'm guessing that plug-in will eventually yield you zero EV only miles, but the car can still be driven as a hybrid.
I've got a friend with an old Nissan Leaf, it's pack is down to 25-30 miles per charge. Still enough to get him to work, plug-in then drive home. Gotta watch A/C usage though; he's stated that the car dropped into tortoise mode a few blocks from home last summer. LoL