Fast Charging with a Prius Plug-in

i would guess toyota accounted for this, but i could be wrong

i don't understand what they are saying, don't tesla batteries have a pretty good track record?

 

The car has a limit to how much current it will allow to flow into our out of the battery before it uses engine braking. There's also a limit to the battery temperature before the ICE comes on. It doesn't matter which direction the current is going, too much current will create excess heat. Think about how fast the battery will discharge at 60 mph in EV mode and then compare that to how quickly it charges coming down the pass. If I'm not mistaken, it discharges under reasonable use way fast than it charges going downhill.

 

Sounds like it's talking about DC fast charging or "Level 3" which is my guess. I can't view the original PDF, and maybe my English ability has degraded over time, but the article is kind of strangely worded in my opinion. "Internal resistance kicks in...", " Internal resistance charging..." Etc.

Also, the whole point of the battery ECU is to monitor temperature of various cells/banks to prevent such damage, so I am not sure if we're to be led to believe Tesla designed their chargers to override the failsafes on the battery while fast charging or what?

I might be missing something though.

 

What the PiP and Prime do when regenerating isn't even in the same universe with, for example, a Tesla Supercharger. I found this chart at Tesla Model 3 V3 Supercharging: Is It Really That Fast?

I don't know the voltage of the Tesla battery (just because I don't have time to research it now), so I don't know the current. Current is what produces heat for those not familiar with electricity. But at 250,000 watts, I'd expect a lot of amps.

Nominal voltage for the Prime is 351.5V. That times the charge limit of 90 amps, that a maximum of 31.6kW. The PiP is lower and both would soon get warm enough to tell the car to stop charging pretty quickly at that rate. That happened to me one time in Colorado just before the battery got full. The Tesla charger maxes out at over 10 times that speed and doesn't drop below that until the battery is over 90% full. We can't even put 90% in our batteries.

 

Yes, with the Prius (incl. non-PHEV) there's a current charge limit and current discharge limit that change dynamically based on SOC, battery temperature, and probably other factors. You can see this with the reports generated by Hybrid Assistant.

 

Using the included cable for my 2020 Prime plug-in, Is there an adaptor that will enable me to connect to a Level 3 station, and will doing so damage my battery?

 

Even if you could, the car would not charge any faster. You can get an adapter ($350) to hook up to a Level 2 Tesla charger but it still won't charge any faster.

 

This is why I stopped using level 2 charging at home. I'd rather save tha battery and let it charge over 6 hours on 120v than 2 hours on 240v.

 

are you saying level 2 will damage the battery?

 

That is a gross misunderstanding of what the differences in charging are, based on assumptions not considering the actual numbers. Ponder this:

Level-2 is just a modest increase in charging rate compared to anything a DC fast-charger would ever provide.

For Prius Prime, it is just 3.3 kW (3.6 max). For the RAV4 Prime upgrade package, it is 6.6 kW (7.2 max). Neither compares at all to the low-end for "fast", which is 50 kWh.

Pushing standards higher, we have 150 kW striving to become the choice for common. It faces a variety of challenges, but no where near barriers the ultimate speed of 350 kW enthusiasts dream about someday having.

With all that perspective, keep in mind that 19.2 kW is the top specification speed for at home charging with a level-2. So, what you stopped is pretty much trivial.

 

Not to mention (as discussed in another thread here) the much faster than L2 charging and discharging that happens continuously as the car is driven. My goodness! If L2 is bad for the battery, them we'd better avoid diving the car for sure.

 

I forgot to mention that I live in socal and am always in a "ready to evacuate" mode due to past events. (my house burned to the ground in 2003 for example.) I know leaving the battery fully charged all the time is not the best practice so I try to make up for that bad habit in other ways. I charge as slow as I can using the 8A limit setting and limit myself to charge once per 24 hrs overnight. (dont use public charging.) also since the "can the AC run to cool down your hot battery" message seems to always show up, even in winter for me, i say no and roll the windows down with a oscillating fan blowing into the car so it stays what the garage is. garage never get over 100 even summer time; it's well insulated and surounded by the house on 3 sides.

 

This issue is regarding leaving the battery in a high SOC for long periods of time, i.e. many months without use. If you're driving the car regularly this is not something you should be worrying about. Even then, it doesn't let you charge anywhere near 100% SOC so this problem is mitigated by design.