slower charge maybe better ?

Why dont you just go down at lunch and unplug it, It will only take like 3minutes...

 

I would say just try the charge scheduler, Its easier on you to have a day when you know you will get to work and leave.

 

I know there has been a lot of discussion about the care and feeding of the Prime's lithium-ion batteries. And there are some very interesting technical charts which neatly plot charge level vs charge time vs lifetime number of charging cycles, etc.

However, I put faith in the Toyota engineers who designed the system to be plugged in and allowed to fully charge -- at which point the charging current draw of the vehicle drops to a trickle. I believe that the charge scheduling feature is intended to be useful if you have an electric rate which is lower at off-peak times or if your Prime is plugged into a circuit which is shared with other loads. (e.g., if you have two Primes in your garage, both plugged into the same 15-amp circuit, and hence scheduled not to charge at the same time.)

In addition, I understand the "full charge" for the Prime is really only about 85% of the actual battery capacity, so the batteries are never really sitting there pushed to their limits.

(The scheduling feature of the Prime is also useful to pre-condition the cabin so that it's a comfortable temperature when you leave for work each morning.)

Maybe I am destroying my Prime, but I just plug it in anytime it is in my garage or near a convenient charging station. That way it's ready to go whenever I need it.

 

Your idea of slow charging would have a few benefits:
1. Like you said, the battery sits at "full" capacity for less time, prolonging battery life.
2. A slower charge should reduce the dendrites formed in the battery.
3. A slower charge will reduce the heat generated (I2R losses) at 8 amps vs 12 amps by 56%
4. If you plug in immediately isn't the battery thermally managed better? I think so but don't own a Prime.

 

Agree with the advantages of slow charging in your situation

 

I too am interested in the potential benefits from charging a 8 amps vs. higher rate (on a 120v circuit - what is max rate - 12 amps?) if I have the time for this lower rate for regular overnight charging.

Anyway since rechargeable battery technology has continued to evolve- and this is my first plug in prius - with Lithium Ion battery - I would like to learn more.

Seems to me as an engineer (but not EE or Chem E.) - charging a battery at a slower rate - if you have the time - is always better for the battery - should increase its health and longevity?

What is best guidance on best SOC to leave the battery at: Charge it up every night - even if you didn't commute/use it much that day? Is it every better for the battery to sit at 80% or 50% vs. 100% ?

Further guidance on better to schedule the charge so it completes just before use - or ok to charge overnight where it will complete and sit full for 4-8 hrs before use?

(I am speaking about small percentage differences obviously - as an engineer I understand EVERYTHING MATTERS/MAKES A DIFFERENCE the question is - are you going to extra trouble/effort to get very marginal battery health/performance/longevity gains? Or could you be adding a few percentage points to these metrics.

Also - with the very limited info from the Toyota app for "charge management" on my Limited - what apps/add-ons is anyone using to "see" more about their battery and it's health and performance - Dr. Prius? Torque Pro? Others?

Also - have seen my EV Distance go up from day I drove it home 22.3 miles - to 24.9miles today after charging this morning. How big a number have folks seen? Would think warm weather - but not super hot - would be peak time for peak miles capacity?

Thanks in advance. LOVING my plug in 2021 Prime Limited.

 

Max is 16A with a 240V L2 EVSE. But that's still only a tiny fraction of the charge rate the car uses when you drive it and are braking or going down a mountain pass. Just driving it in Charge mode is charging the battery twice as fast as L2 charging and that's not as fast as B mode down a steep mountainside. The fastest charge rate available is still slow compared to the current in & out of the battery while driving. Nothing to worry about there.

We're all still learning.

100% on your display is actually 83-84% real world. The manual says it's best to sit at 0% which, iirc, is about 23% real world. But a lot of battery experts seem to think it's better at around 50%.

Just before use is healthiest. Letting it sit fully charged for extended periods will cause the battery to degrade more quickly. The thing is that the Prime hasn't been around long enough to know exactly how pronounced that effect is. So far, it doesn't seem to be extreme, but I do not let mine sit fully charged for more than a couple hours at a time. The scheduler makes that easy in most situations.

I'm a little envious of some of your car's features, but I still love my old 2017 Premium. Fantastic car with a few "what were they thinking" features.

 

You could always plug it in and not start the charger, and use the app to start the charger, or stop it, whenever you'd like....

 

For emergency purposes, it may be affected.