Switched To Schedule Charging Finally

Out of fear of having a new lithium battery charging in our garage, we decided we wanted to be awake while the charging.

Having set the charge current to max, the 120v CCID/EVSE draws right at 12A from the wall, and puts 1135W into the battery up until the last 30 minutes which averages around 700W. Our garage temperature is around 80F at night, and the car’s battery cooling system can be heard operating when the car is connected to the wall. The rear cargo area temperature is elevated slightly during charging, and a very slight “burnt smell” detectable in the vicinity of the charger on the left of the cargo area.

Since our average daily travel has been 24 miles at an average 4.3 mi/kWh, the nightly charge averaged a little over 5 hours. I typically started the charge when we got home around 8 or 9PM and interrupted the charge at midnight to go to sleep. Then the next morning was restarting the charging which was taking another 1 to 4 hours to complete. Combined with my desire to measure everything, I was not sleeping well and really spending a lot of time on charging our new car. I kept waking up early wanting to complete the charge to have another datum in my quest to understand the car.

After 3 weeks of this obsession, I decided the car charging did not seem likely to burn the house down soon, and if it did being awake inside the far end of the house might not alert us to the danger any better than as
asleep when the smoke detectors would scare us into hyper alert.

Part of my measurements showed that having the car connected to the wall before or after the active charging period did not draw enough power to alter my kilowatt meter reading for the charging session significantly, so using the schedule charging feature would not corrupt my data collection.

I used the Toyota app to set charging to begin daily at 2AM, reset the wattmeter, and connected the car to the wall. I still woke up earlier than desired to listen for the Toyota app to notify me of charge complete, so I could collect and document the charge statistics, but it cut the “work” of charging in half.

Before purchasing the Prime, I was only having to record my (gas) fill-ups about once every three weeks. Now it is daily for my electricity fill-ups. I did not realize this aspect of owning a plug-in hybrid before, and while it is exciting to have joined the “electric vehicle owners” community, I am not yet used to the new routine.

I know I will never be content to “just drive it”, but owning and driving this car is so much fun and is rewarding beyond my expectations.

 

Where I live the average daily commute is 25 miles according to the 2021 Florida DMV report.

This is an important constraint, true. The average commute will require a 5h 30min recharge overnight with the provided 120v EVSE. Public charging is a novelty for Prime owners, nothing more.

PHEVs manage the maximum charge to extend battery life, where BEVs do not. The Prius has since it’s inception maintained a reserve at the top, and the bottom.

Additionally, Toyota chooses a larger reduction factor for the EPA report than Tesla, resulting in Toyota vehicles getting better than EPA range, and Tesla owners seeing less than EPA estimated range.

 

Yes they are warm but not more than I expected for 120v at 12A. My watt meter plug is also warm, but nowhere near melting anything - they both pass the comfortable to leave your finger on the metal test.

One of the losses in the roughly 75% efficiency of the charging process.

 

Dr Prius is reporting 97degF when charging at 4A-4.3A at the battery when I'm charging. I am relying on Toyota battery cooling big time. My 2009 Prius battery was still "healthy" at 14 years and 109K miles in Florida heat with Toyota battery management. I want to trust Toyota even though I am not fully on-board with carrying a Li-Ion bomb around and parking it my garage. I also like garaging my car, so I'm putting my trust in Toyota.

 

Trying that as a test of MPG at the moment. I think to actually use gas significantly I’m going to have to either burn the EV mode charge down to 0, or maybe drive HV mode on the freeway, or try charge mode