Doubt on battery and solar panels

[antonpirulero]

Hi, I have a model 3 LR that I would like to charge with solar panels. The charger is able to intelligently use surplus output, but I'm afraid that will be bad for the battery.

In the car manual the first and most important thing it says about battery care is to keep the car plugged in when parked at home. If the charger decides when to provide power to the car based on solar output, the car will in practice be unplugged for many hours. This will not mean the battery will be depleted, the car will just be automatically unplugged when there is no sun.

Will the car battery be damaged if I use the solar panels? What is the best option?

 

[Sophias_dad]

The car battery won't be damaged. Treat the solar panels as a normal power source. The car won't charge if it doesn't need charge, and if you run out of sun in the middle of a charge, it'll just stop charging. It'll >probably< continue charging again automatically when the sun comes back, although there's a random ~3 minute delay timer built in so a fleet of teslas doesn't overwhelm the power grid when it comes back online.

I don't know the details of your solar supply, either. If the voltage slowly diminishes instead of turning off when the sun goes behind clouds or its own battery starts to run out, the Tesla might view that as a fault and stop charging, but not restart on its own. In any case it won't hurt the Tesla at all.

The advice about the battery being plugged in while at home isn't all THAT important. I'm sure if I had a commute that required >50% of my battery I'd do that, but now that Covid is here I haven't been to work in person since 03/13/2020 and my car might get plugged in every week or two. My estimated 100% range hasn't notably changed in that time.