Uneducated charging question: My daily commute eats up about 50% of EV capacity when driving in hybrid mode. If I have to run an extra errand on the second day, I run out of EV capacity. Will it degrade the battery more charging most days from around 50% back up to 100% vs charging every other day from near 0% ?
No, you can charge any way you want. Toyota has built in protection for the life and health of the battery
Thank you. Uneducated follow-up question: is there not a limited, predetermined (?) number of charge cycles, and does each charging- from whatever percent consitute one?
That’s more of a scientific lithium battery testing question than specific to Toyota chemistry and software. All I can tell you is that Toyotas process has resulted in 13 successful years of plug in vehicles under any conditions you can conceive of, and the failure rate is almost nonexistent. And range loss over time is minuscule
What bisco said. Normally, for all lithium-ion chemistries, the larger the depth of discharge the more the battery degrades. So it would be better to discharge to 50% 200 times than to discharge to 0% 100 times. However Toyota is not going to let you hurt the batteries. An you are not discharging to 0% anyway.
Does 50% of the prius's usable battery match up with 50% of the batteries actual state of charge? I don't know what safety buffer, upper and lower, Toyota uses for the lithium batteries.
As close as most of us that use aftermarket scan tools can pinpoint the buffers, it looks like around 15 - 16% on top and somewhere between 10 - 15% bottom. It might be possible to narrow that percentage per individual car using techstream, but I doubt it will get any closer to a general average, at least in human observable terms. If you want to know more you can get an after market app or techstream and compare what you see on the cars gauges to what you see on your phone / tablet and / or laptop. Some after market options that will show you are: scangauge 2, DrPrius, Hybird Assistant, Car Scanner, (( Autel AP200 or AP2500, Thinkcar Diag) i'm told)), DrPrius has this feature that tracks the packs internal resistance per cell for Prime or module-pair for Prius. It's interesting to track how that graph can change over time. Especially when (( changing the charging of a plugin ) from what the car shows as 50% or 60% SOC to full charge for at least a month or two, than switch to charging from 0% SOC to full )). The internal resistance graph also gets all funky, and resets after a few days, when it gets cold in winter. It shows that something inside the pack is happening when the car is exposed to different outside influences, like temp, rate of charge and rate of discharge, as well as changing normal, daily, consistent, charging routines. It's not, a walk in the park easy to grasp, since it doesn't provide written explanations of exactly what is causing the internal resistance to fluctuate so noticeably, and than reset and return to what one normally sees on a daily basis.
The battery manufacturer lists the rated charge cycles for the batteries they sell in the batteries spec sheet. They also list things like the max / min voltage of the batteries and max charge rate in the specs. One way of making the battery packs last longer is by not allowing the batteries to charge to 100% SOC or discharge to 0% SOC . Charging to 100% and discharging to 0% is 1 cycle of the batteries rated number of cycles. So Toyota and every other car maker I know of buffers the top and bottom of the battery pack so that when charging / discharging we never use a full cycle.
I attribute the long life of my Gen 3 plug-in lithium battery to not charging it most of the time. Side rant: I hate "meta-answers," where they tell you there is an answer to look up somewhere, but don't even give you a summary of what it is.
I think 30% is the sweet spot for lithium, which is the top of the bottom buffer for Toyota. But that’s for long term storage. Just drive it is my motto, because these batteries will last longer than the rest of the car
