2021 Plug-In Battery Question

Didn't claim it wasn't an issue with gasoline. Just mostly one with diesel because of the difference in volatility. Any gasoline in the oil will mostly be boiled off when things reach operating temperature. Diesel won't because its boiling point is higher than the recommended temperature range of the oil. Small amounts of gasoline generally aren't an issue while they are with diesel, as the diesel doesn't leave the oil.

Which is exactly what will happen if you take Toyota's instructions of storage for the battery as something best done all the time.

Iron rusts faster in water than in dry air. Water is not a benign compound, and its presence will influence those reactions. Likely not in a good way.

 

Hi Trollbait, sorry I missed your question back then. Our Japanese imported, Gen 2 Prius Plugin hybrid has 2 buttons for selecting modes. One selects EV/HV (and traction battery charging if pushed longer), and a second button for Eco/Normal/Power. For everyday city use I use EV and Eco modes as this greatly reduces the automatic switching from EV to HV mode when accelerating lightly on motorways. I use Normal (instead of Eco) if I expect to use the ICE motor a lot e.g. long distance trips or with heavy loads. Apparently in Eco mode the ICE motor runs rather lean, which some say is not good for the ICE motor.

I would like the EV-City mode for normal city commuting, as I think it stops switching to HV (almost) entirely by limiting the max power available. This would be great for commuting to/from work using the city motorways.

 

Just the one EV mode? Not two like the North American and European models?

You might be able to switch on the NA or EU configurations. People in the US switch the i3 REx to EU operation. It is a question of finding someone that knows how to do it.

 

Not yet stated in this thread, in addition to avoiding extended times at a vehicle-reported 100% SOC, shallow discharges produce less wear-and-tear on a lithium-ion battery, compared to deep discharges. All other things equal, two charge discharge cycles 75% to 25% produce less battery degradation than one discharge cycle 100% to 0%.

My point being that if topping-up on the road keeps you away from 0%, and so keeps that current discharge cycle shallower, that's probably a good thing.

Separately, I finally found the National Renewable Energy Labs research that I had been looking for, regarding the odds of early loss of range in a Prius-Prime-like vehicle. They've simulated what eight years of normal wear-and-tear would do to a fleet of Prius-Prime-like PHEVs. The only material difference between what they are modeling and the actual Prius is that their car only has a 10% buffer at the top, whereas the Prime is reported to have about 15% buffer (i.e., true state-of-charge is about 85% when the car tells you it's 100% full). They did not add in factors for (e.g.) excessive heat and such. So this just shows what they would expect, after 8 years of "non-abusive" use, in a fleet of cars, where driving was modeled on actual driver behavior of about 800 recorded trips. Below, "PHEV 40" is the most Prime-like vehicle.



Source: doi:10.4271/2012-01-0666
SAE MOBILUS

Absent any other factors, they expect the average user to have lost 20% of range in eight years. And maybe 5% of users will have lost ~25%.

The range losses appear really tightly clustered, to me, but I think that's in part because the only thing they allowed to vary was typical per-trip behavior.

That said, I think this explains why nobody but Volvo offers a warranty on PHEV range. Take the plot above, toss in some random bits of abuse by some drivers (high temps, extended storage at 100% SOC, etc), plus a battery that reportedly costs $12K plus (per the Rodent Damage thread here), and I'm betting that expected warranty losses would just be too large.

 

Yes, that button can only select HV and the one EV mode. The second button has an Eco function, which does modify the EV mode - it raises the speed/load threshold when the motor is automatically started. I'm getting used to it (until I find a suitable enthusiast to change it to make the tweak).