Li-ion and Ni-Cad batteries treated as one?

You are welcome. I think the info from your research could be from the pre-production prototype model. It had 3 battery subpacks and one of the could be NiMH. It also did not have a flat cargo floor.

 

OK, let's analyse this.
If 23% SOC is "6 bars on the HV battery icon" (no EV miles) and going from 6 to 2 bars equals to about 200-220 Wh which is about 5% of battery rated capacity, then deducting 5 percent points from 23 brings us to about 18% SOC not 20%.
In my opinion 18% is too low for battery health, so trying to "milk" the system to as close as possible to 2 bars just before coming home for charging is not a clever strategy IMO.

 

Not sure if it goes down to 18%. Might be 19 or 20%.

I definitely respect your opinion but I will trust the Toyota engineers.

 

As I am planning to own the car for more than 5 years (the warranty here) I intend not to make this a habit (not saying I will never do it though).
On second thought, If the new model will be very tempted...

 

Toyota recommends long term storage in HV level SOC. Perhaps, 18%-23% is better for their Lithium chemistry.

Ford Energi plugins also used the same cells from PEVE (Sanyo) and they use even deeper depth. Toyota is being conversative with PiP.

 

Toyota recommends long term storage in 6 bars HV (just when it turns from EV to HV as they say) so at 23%, I still believe 18% is too low.
I thought PEVE is Panasonic/Toyota joint venture, not Sanyo.
EDIT: I see now that PEVE was Panasonic/Toyota until 2011 but not any more.

 

PEVE was Panasonic/Toyota until 2011. I think PiP prototype used Panasonic Lithium cells. The demo/test was successful but when the time came for mass production rollout, they found out it is very expensive to manufacture.

My understanding is that Toyota delayed PiP roll out together with Gen3. They found out Sanyo Lithium cells are better and less expensive to manufacture. So they bought Sanyo battery business and the production PiP has Sanyo cells.

Oh yes, Toyota fixed their process so the mass production cost study is done at earlier stage.

 

I agree. The target SOC in HV mode is 6 bars (23%). I would not go lower than 20%

I don't think it is a good idea to drive PiP until SOC is 18% and leave it for a long time. I think it will be very difficult to get it that low because computer will try to charge it up with the gas engine.

 

I personally have never seen it below 20% on Torque (and I'm one of those that squeezes a lot of juice out of it)

 

Good to know!

 

Also, fwiw, I strongly believe that driving the car around like a bat out of hell (or even somewhat so) in EV mode is far worse for battery longevity than storing it for a day around 20%.

 

Agree.
Squeezing the last drops of juice, as you put it, requires very careful planning ahead in order not to find yourself at destination with '6 bars' on the HV battery, or, god forbid, 0.5 EV miles left!
Hope you are not making one extra cycle 'around the block' or any other trick of "flight to nowhere" in those circumstances

 

I got it down to 4 bars in HV mode today. It reads right around 20% SOC.

 

it varies depending upon conditions. if you're in creep and crawl traffic, you can get it down to 2 bars.

 

SOC % is from Torque app. Target SOC in HV mode is 6 bars (23%). It may swing lower or higher depending on driving condition.

Also, the bars are not linear. This is from a regular Prius NiMH battery with smaller battery.

 

I don't think I can get my PiP below 3 bars.

 

You need the Pro version to use the custom PIDs.