Gen 4 Prime (2020) not fully charging anymore

How do you measure the kwh? The estimated range does fluctuate on previous driving conditions. Maybe battery temp is a factor.

 

What is your climate like? It sounds like it may be a battery state of charge capacity problem. Are you cycling frequently or leaving it fully charged for long periods of time?

 

Do you use an app to monitor anything besides kW s into the hybrid battery

 

I'll sound like a broken record but Hybrid Assistant is great for that.

 

There an eco diary which shows the daily and monthly miles/ kwh. That would show the efficiency changes. Maybe if you drive only ev around town for awhile and see if anything changes in the capacity. I don’t know why it would, because full ev’s drive highway not losing capacity. Or maybe they do. You do use the battery intensively for long periods going those speeds

 

I didn't want to ask it, but I'm glad you said it. Those speeds in EV mode is gonna do in the tiny EV battery. It gets even worse when driving those speeds and running out of EV range and having the engine switch on cold. Even 100 F is cold for the engine at those speeds. A lot of owners have posted that is how they drive their Primes.
It wouldn't be AS noticeable in the Gen 5 Prime as it will be in the Gen 4 Prime, and even more noticeable in the Gen 3 Plugin even though it's top EV speed was 64 mph if I'm remembering right.
DrPrius and CarScanner are also useful apps.

 

If I know I'll be needing the engine later on in my drive, I'll warm up the engine before going by turning the defrost on and off. It doesn't take long for the engine to warm up, if you still have your exhaust heat exchanger that is lol.

 

I don't think Prime is meant to drive extensively on EV mode (especially at high speeds). Yes, it has an advertised 25-mile EV range, but it is still primarily a hybrid vehicle with much smaller battery compared to full EVs. My understanding is that you are driving your vehicle on EV whenever possible and charging it every day. This type of extensive use will cause battery degradation no doubt.
Every time you power of your vehicle, it gives you an EV driving score based on 4 parameters. May I ask what score you typically see on your screen?

 

I think I got my answer

 

Some code reader can tell the battery capacity percentage, like BlueDriver. I got 86.3% on my 2018 PP when I tested in June 2023.

 

Can we assume that the charger is stopping at 100% indicated? You never said. If it stops short of 100% that's a different matter.

High speed EV driving will increase the wear on the battery for a couple reasons. One, the higher current is hard on it. Also, since you're using it up more quickly, you're probably increasing the cycle count and that's another wear factor.

However, battery degradation is neither an indicator nor a cause of low mi/kWh except if it leads to more frequent charge/discharge cycles.

Dr. Prius should tell you what's going on inside the mysterious aluminum box back there.

 

I wouldn't rely on Dr. Prius for a Prime. Email I got from them:

I don’t think Dr. Prius App is fully calibrated for the 2017 Prime yet, we only have a chance to work on the Gen1 plug-in Prius, we need to find a test car and calibrate it, FYI.