I ran across this article and thought it might be useful to others with electric vehicles.
It goes against all charging conventions but not against some articles I have read where it is only fast charging that leads to most batter degradation. The choice is yours but I thought getting real world experience out there would be helpful.
Not sure what this has to do with home assistant.
And if anyone changes their charging behavior based off this post, they’re an idiot.
Who defines here what is 100%? Li-ion cell could be charged to 4.1V or could be charged to 4.3V. But there’s difference for battery cycle life…
I have a Powerwall 2, and is charged to 100% every day, and it is guaranteed to have 80% of its life after 10 years. It’s charging rate is greater than what my Level 2 charger is at 32 amps. I have two electric vehicles that I routinely charge to 95% with a level 2 charger, and I have seen no degradation on my batteries after two years. I think it has a lot of relevance, especially when vehicle to house becomes more available. That is my opinion, and you are certainly entitled to yours, Rick.
Ok, one line of code and same charge level can be printed as 95%, it’s not absolute value.
Glass bottle is 100% full when no drop can fit anymore.
But balloon is 100% full when …?
Battery is 100% full when the BMS shuts off. I get 25.65 kwh available every day when charged to 100% on my Powerwall. Same for a vehicle only the kwh will be higher.
And BMS shuts off when it’s programmed to shut off…
Anyway, no need to go further here, I described my point as well as I could.
My point is the same as Karosm’s. The BMS manufacturer’s algorithm defines how to calculate SOC and therefore only the BMS manufacturer knows what “100%” means. And it is different for each BMS, each battery chemistry, each pack, and even different each time you reach 100% because one day one cell may have hit a specific cell voltage, and a different day the coulomb counter for a different cell reached that cell’s capacity based on its SOH.
And we haven’t even talked about battery degradation. Again, guess who defines how degradation is calculated?
And should we talk about chemistry here? LFP is well-known to be happy to be charged up to its capacity and stored there with minimal degradation. NMC? NCA? Not so much.
The point being that charging one product to 100% means absolutely jack squat when comparing to a different completely product.
If someone already understands all these intricacies, they aren’t going to change their charging behavior of their own vehicle based on one person’s experience with a ford lightning.
If someone doesn’t understand these intricacies, and they change how they charge based on that post, I maintain my previous statement that they are an idiot.
Also note that I’m not making any claim as to whether or not charging any specific battery to “100%” is or is not a good idea. There are cases where it’s fine and cases where it is not. If someone doesn’t understand all the various detail (and often some of the critical info is hidden inside the BMS algorithms), they should rely on the manufacturer’s recommendations.