Real Prime Battery Capacities

The faux window sticker gives the miles/kw as 2.9 = 39 miles divided by 13.6kw. Not convincing. I'm hitting up a commercial charger tomorrow.

 

Until it's on Fueleconomy.gov or a Monroney label, it isn't official.

 

Is there like a hold mode in the 2023 to retain more useable battery, and this is turned on to retain 30%? Not sure about the app would show the total battery capacity level in %? I think it would be showing useable %. To me it can’t be right the charge from empty is only about 1 kwh more than a gen 4. Toyota states 4 hours charging on 240, 11 on 120, approximately. Figuring 20% charger loss on 120 and 10-12% with onboard charger, it comes in appx right at the 11.5 useable capacity doing a rough calc. Gen 4 is about half those charge times, 2 hrs and 5 hrs. The charging losses are about the same from my rough figuring.
I am still figuring how to use the charger port lock options, think I got it. Auto lock on inserting connector is what I want. Keeping it locked on charge complete using my own charge cord out on the streets. If using a public charger I should change it to unlock on charge complete to be neighborly to others waiting. It took me a long long time to figure it out. I have gen 4. This is not on topic other than my owners manual, at least my gen 4, is a long read and complicated. So imo there has to be something going on to have only 7 kwh getting a full charge from empty.

 

LOL 7.5 kWh useable BEV capacity is simply totally wrong, as you are doing a mistake in your calculations and/or measurements.

Even Gen 4 has 6.34 kWh, and Gen 4 is more fuel-efficient than Gen 5. You would only get a 25-mile BEV range with 7.5 kWh on your XSE, which would be the same as that for Gen 4.

 

Look at the window sticker. It is official, and there are no footnotes.

Toyota inventory | New-Toyota inventory search

 

Brought my car to a Chargepoint station today, so here are the data points to do with what one will.

Chargepoint App reports 11.65kw . Toyota App reports 7.21kw.

 

Window stickers are available online at some dealers. I just looked at one for an xse. 114 mpge and 48 combined mpg. The range is listed at 39 miles. Chargepoint screen data is what is put into the onboard charger, not the battery. I guess 5-12% loss. I could see it easily on the Volt.

The Prius charging tapers down to under 800 watts before stopping and declines from max gradually over about 10-12 minutes, never timed it exactly. Makes it hard to calculate using charging time.

 

Regardless, the kWh that comes out of the plug is what matters when you calculate mpge. It is just like the gasoline-tank capacity—you don't take into account how much gasoline evaporates, what is conversion efficiency, etc. when you calculate mpg.

The switching-mode power supply of a PHEV/BEV has an efficiency around 96%. The rest of the energy loss goes into motor and drivetrain losses and braking. 12% total loss should represent that. Also, charging is less efficient when the the battery is getting close to 100% SOC.

All that said, I think the fuel efficiency of Prius Prime XSE and Prius Prime XSE Premium is dismal—not a green EV at all. You lose features like auto-on lights with Prius Prime SE; so, I am having second thoughts on my trade-in.

 

Yeah, but Prius used to be synonymous with the pinnacle of fuel efficiency. 2021 Model 3 with 142 mpge has 25% higher fuel efficiency than 2023 Prius Prime XSE/XSE Premium with 114 mpge.

Moreover, Prius/Prius Prime has lost cargo and interior space with Gen 5, compromising useability and comfort.

 

I don’t know what you are saying. The gas is pumped into the tank, you get in the tank what the pump says at that moment, and the pumps are inspected for tolerances. It’s only to that point in the power use chain, not after, power train losses etc. Not so with a battery, it gets less than the supply delivered. That’s fine I don’t need to be a scientist to drive a Prius. Just let it do it’s thing. I doubt all onboard chargers are built equal though across all makes.
The chargepoint app tells exactly how much power was delivered, the car may show how much was received in the battery. I remember the Volt had something, I think, not sure about the Prius. I “feel” the Volt was less efficient charging than the Prius.
OK I searched and found your favorite on top, car and driver, but it seems to explain a lot to me even though I didn’t read all of it. This all takes a lot of time.

EVs Explained: Charging Losses

 

Part of the gasoline in the tank will evaporate. Energy losses start when pumping the fuel–air mixture into the combustion chamber, then combustion, etc.

For the same reason as what matters for mpg calculations is the meter reading at the pump, what matters for mpge calculations is what is shown on the kWh meter, not what is actually stored in the battery.

As I stated many times, 11.7 kWh should be the Level-2 energy shown on the kWh meter on the plug when you charge from 0 to 100% SOC on the car's display meter. If the charger consumes 5% of that, it is only 0.6 kWh, which will be part of the battery buffer and is no big deal. Level-1 energy through the plug will be higher. There is no reason to obsess with the battery buffer—every battery has one.

Gen 5 useable HEV reserve is about 0.8 kWh; so, the total Gen 5 battery buffer seems to be about 1.7 kWh, leaving 11.7 kWh × 0.95 = 11.1 kWh for BEV driving out of the 13.6-kWh battery.

 

Well this turned out badly, like so many discussions in text. Please read the article.
I think the op was answered, yes the car goes into hybrid mode at reaching the lower buffer, maintains that lower buffer with the engine, and the upper buffer is reserved for preventing overcharging.
No worries, just drive a Prius and think about life, they make it simple and decide the buffers for you. All done on my side, man what a lot of time spent, whew.

 

We all knew about the lower and upper buffers.

I was pointing out that the 10.9 kWh specified by Car and Driver is wrong. The EPA value is 11.7 kWh, not 10.9 kWh. I provided the nice EPA formula for that for those who were interested in it.

 

Aha, that's exactly what the EPA formula gives!

BEV charging capacity (kWh) = 33.705 kWh/ge × BEV range (mi) / mpge = 33.705 kWh/ge × 44 mi / 127 mpge = 11.68 kWh

So, @Mr.Vanvandenburg and @Exerted, it has now been verified that the EPA charging-kWh value of 11.7 kWh is correct, and the Car and Driver value of 10.9 kWh is incorrect, as expected and I have been stating over and over again because people have a tendency to believe car blogs rather than EPA and have kept questioning the value I obtained using the EPA formula. Case—finally—closed.

By the way, the EPA formula I provided is a very useful one; so, keep it recorded somewhere.

@Numtini, as for the Toyota app, it sucks.

 

I never said your 11.7 was incorrect as far as I remember. It probably shouldn’t be a contest, it isn’t for me. I put a link to charger efficiency losses by car and driver, had nothing to do with battery capacity. When it gets to be a personal contest it becomes nothing more than a shouting match in my opinion. I hope Weber auto does a 2023 review on the electric motor and battery, he gets very detailed info.
Looking forward to his in depth report on what has changed in the 2023.

 

Yah, but I'm a nerd and I want to know how does it suck? It's numbers are logically consistent and at least in some places match what the dash and outside sources are telling me. Did someone forget to switch km to miles somewhere? I must have answers!! (And yeah, I know I'm not going to get them.)

My kw/m (4.6) and range (52 miles) come out to close to 11.6kw. So loss seems to be minimal.

 

If that’s a completed 52 mile trip, you have to subtract the regen. Charger losses, and heating/cooling the battery losses can be quite a lot from the delivered kwh. It never is going to be what the supply kwh says you pay for equals what the battery got. I posted a link to cd testing of the subject. Regen is always a factor in range.
I am pretty sure the Prius has a screen telling the amount regenerated each trip. I know I saw it on my gen 4.
I put my bet in the useable is 10.6 kwh. 3 kwh buffer total is about right.

 

Ah! Mea Culpa! I'll take down those stats. Which might bring us back to 7.21...