Prime 2nd gen battery size - usable vs installed

I am pretty sure that this has been asked and answered in some other post, and I apologize if this is a repeat, but I cannot find an answer using the forum search.
What is the gross battery size of the Prime (2nd gen) and how much of it is usable?
Wikipedia says (because looking for this information on Toyota's website is a nightmare) it is 8.8kW. Somewhere in the forums I found that usable is 6.2kW.
Is there really a 30% buffer? that much?

If that is the case, for the 3rd gen coming out this year - Wikipedia and Toyota.it (the only official Toyota website where I could find the number) say that the battery will be 13.6kW. Available to charge then will be 9.5kW? (i.e., 13.6 - 30%) or another number?

 

2016. See linked article in Wikipedia. I bought the car in Feb. 2021.

 

Thank you. I also rely on what the charger tells me when I go from 0% to 100% charge.
I forgot that the 30% buffer contains the HV mode “battery” charge.
What is the overall battery buffer then reserved for longevity?

 

Thank you very much for all the details.
I’ll use the same assumptions as I calculate how much of $$$ I could get from a 2023 vs my current 2021.
But the prime is already SO efficient, that it will be not much at all. At that point I’d get a 2023 for other reasons other than energy savings.
Coming from a regular 20-30mpg ICE vehicle, even at US gas prices, the Prime (or any hybrid or EV) would save you hundreds per year.

 

I have to agree with @Salamander_King. When I reach 0% SOC in EV mode and I recharge the battery at, e.g., ChargePoint, I get "fuel-ups" of about 6.2kWh. There is no reason to think the HV portion of the battery is any different than the regular Prius, so it should be around 0.75kWh. I would also assume it is 100% available (no buffer for the HV portion, which is a logical allotment, not a physical one). Hence, what is remaining of the overall battery as a buffer is 1.85kWh or about 20%, not 30% as per graphic.

Therefore, in the new Prime 2023 (gen 3), assuming they are using the same allotments, removing 1.85kWh as buffer and 0.75kWh for HV driving mode, would leave 11kWh for EV-only driving. That would equate, assuming all other things are the same (including the car's weight and tire rolling resistance) to a total range of 51.7mi vs the 29.7mi I get today at my 4.7mi/kWh average. That would be a 75% increase in EV-only range.

If, instead, the buffers are not absolute, but a % of the battery, then a 20% buffer for the new 13.6kWh battery would equate to 2.72kWh (and not 1.85kWh), leaving 10.13kWh for EV-only driving after removing the 0.75kWh required for the HV driving mode. That would yield 47.6mi range @ 4.7mi/kWh in my case, or an improvement of 60% vs the previous generation.

In any case, the increase in EV-only range would be well above the 50% mentioned by Toyota. Unless...the new 19" wheels and the (extra?) weight would eat into the gains of a bigger battery, bringing "only" 50% increase.

Getting a new Prime 2023 to replace my 2021, based on the above, would bring savings in terms of gas and electricity of about $50-100 over two years of ownership. Essentially zero benefits. I would surely emit even less CO2.
And if you factor in the registration of the new car and higher insurance (new car vs a 3 year old one) I would "lose" money in fixed costs.

I would of course get almost twice as much power, more "oomph", bigger trunk space, and finally a more modern entertainment system with wireless CarPlay. Of course Toyota had to go cheap with the screen and cameras, so their resolution, I am reading and hearing in reviews on YouTube, is not up to a 2023 car...
I am also hoping that the TSS3.0 will bring an LKA with lane centering that doesn't "wiggle" like on my current Prime (hence, always off), and that the new "traffic assist" is working well, instead of being a beta version to be improved in TSS4.0. Oh wait, there are OTA updates - maybe we will really get updates that improve on the software, instead of having to buy a brand new car...