Looking at 2017 Prime, any way to verify battery health?

Like you, I have been reading for a while, and I am also about to buy a Prime.

I would expect the traction battery to be charged up to a safe level on every test drive, and in that state it can probably sit for months. From what I have read here the 12v battery can suffer damage. But it is probably (maybe?) fine. Perhaps the dealer could give you a deal on that to ease your mind. Like "if the 12v fails in the next 12 months we'll swap it for free" or something along those lines.

This one I have learned from reading the forums . My understanding is that using B is the same as pressing the brake pedal. What does that mean?
- In EV mode, it will regenerate more than D while coasting (i.e. slow down quicker)
- In HV mode it will spin the engine (without burning gasoline) to slow down
Should the battery not be able to safely accept more charge, the engine will spin.

 

There are ways to get a general idea of Traction Pack Health, although they do take time to learn how to take the readings and get the reports.
see DrPrius app or HybridAssitant and Hybrid Reporter. I've read here that both will do a traction pack module by module check. To use the apps you also need to get a elm327 odb2 bluetooth adapter and pair it with the app, than learn how to set it up and use it.

B on the shifter just gives regenerative braking. And it's a static amount of regenerative braking, unlike a Tesla which you can adjust the amount of regenerative braking from the controls screen. Using the brake pedal is a bit more complex than most ICE Internal Combustion Engine cars. Pedal braking is computer controlled in the Prime and most other EV's too. The computers determine how much of the braking is regenerative and how much is physical pads and rotors.

There is a Charge Mode you can use while driving the car. If there is less than 80% of a full charge you can switch on Charge Mode. It takes about 1/2 hour to charge from 0 EV miles to 80% full charge - however many EV miles that will be in any one particular Prime.
Press and hold the EV/HV button for 5 seconds and you'll see Charge Mode instead of EV mode on the dash.

It's also possible to use the left side steering wheel lower button to switch through the 5 trip meters on the odometer and they will show mpg's from the odom, tripA and tripB

There's also a bunch of screens on the MFD and MID displays to give clues to how the car has been used on previous trips. Those also take a while to learn how to find as well as understand what they are showing.

 

First, good answers, @Henrik Helmers!

And welcome, Carl.

Almost certainly nothing to worry about at this age unless the previous owner stabbed it with a knife or something. The Dr. Prius app and a quality OBDII bluetooth adapter are about the most convenient way to check the battery health. Not free, but fairly inexpensive and may come in handy later.

Henrik answered well. B is for going down big long hills -- the ones that tell truckers to use low gear. If the Prime is in EV mode, it will regenerate more strongly, thus slowing the car more than just coasting. Because of that stronger regen, some people like to stay in B all the time when driving EV. I played with it and it was more of a nuisance to me. If the Prime is in HV mode and you're going down a mountain pass, B will let the car's momentum spin the engine with no fuel burned, using it as an air pump to provide braking in order to keep you from overheating your brakes.

That's the main thing I wish my Prime had that my trim level doesn't offer. I can see that it would be very handy. It does need to be adjusted properly for it to be visible. It's likely that the one you drove is set for a taller or shorter driver.

Totally worthless. My wife's car has it and we've never even tried using it. If you can't park the car, learn how or don't drive on the public roads.

 

I'd love to see a pic of a car with brakes smokin, like seen in the western US when rigs are runnin the leeward side of pass and 80 mph. Love that smell. Or like on the show Ford vs Ferrari when the shelby brakes got red hot and failed causing the car to crash and catch on fire. LOL

 

The traction battery is fine sitting at a low charge. In fact, that is how Toyota suggests to store the PP when not driven for a long period of time. I would be more worried about the 12v battery as someone above mentioned. Just have the dealer do the 12v battery check on it, and if lt is not up to per for 3 years old 12v battery, then have it replaced at the dealers cost. It is only ~$100 battery. Also depending on where it has been driven, you may want to check the rust on the suspension and around the brake. It is not likely the rust in those areas and elsewhere underbody exposed to the road salt would cause any problem immediately, but if you plan to keep the car for a long time, you may want to check it.

I recently bought 5 years old SUV which had been driven on New England salted roads for 5 winters. The underbody was totally covered by surface rust. Before going into the 6th winter, I had it treated with FluidFilm underbody coating. This car, we plan to keep at least another 5-6 years, so I feel better now.

 

Do you wear polarized glasses or sunglasses?
You may not see the HUD with them.
Otherwise, there maybe a brightness and position adjustment for it.

 

Carl - First, let the dealer fully charge the traction battery, then let them adjust the HUD so you can easily see it. The HUD will give you an estimate of how many miles you can go on EV, thus a rough estimate of the battery health. It is also based on data from previous trips, so 2 or 3 charges may be necessary to get a good reading. It is also based on ambient temperature, so if it is getting colder in Wisconsin, you will get less mileage. As an example, I typically get 29-30 miles when the temperature is 70-80 and 25-26 when it is in the 40-50 range.

 

@Washingtonian, today must be my nit pickin day for some reason or other, and I hope it doesn't turn off too many readers, even though I understand it very well may.

With the estimated EV miles (or as some here like to refer to it as the GOM (guessOmeter)) the HUD shows,
isn't it purely based on previous EV only driving range and or previous EV/HV driving ranges? And if yes wouldn't that make the estimated EV range or GOM measurement a poor at best indication of traction pack health?
I say above due to the fairly large spread of GOM or EV range measurements members here have posted. somewhere between low teens to anywhere in the high 40's mile range.

It's easy for an experienced hybrid hyper miler to get well above 40 estimated EV miles, where as another driver who only drives the Prime like any other ICE car have complained here at PC about not being able to ever get even the new car stickers midrange listing of 25 estimated EV miles.

With my Prime, I'm still very concerned about traction pack health and longevity since this is my third hybrid and I still have one that has had pack issues since 2013, right after an undocumented IMA update.

 

As I read the last two posts by @Washingtonian and @vvillovv, it looks to me like Washingtonian has a valid means of checking battery health but it's really time consuming and would depend on the tester being experienced in driving other Primes.

The simple way to check is to use a Killawatt meter to power the EVSE cable and charge from fully depleted. It should take over 6 kWh to fill a healthy battery.

 

A 2017 is still going to have a considerable term remaining on its transferable factory warranty which provides general coverage for this traction battery. Take that for what it is: a diagnostic might be less necessary than you think.

 

if it were me, I'd wait for a sale and go new. especially if there are any leftover 19 plus. Might even be able to match that figure.