Those charging protocols don't have a single company that maintains all of those chargers. Another thing, and I did this while test driving EV's when looking for a NEW EV, all the more so if I was buying a USED one, take the EV out and charge it as part of your test drive.
When I test drive a gas car, I sometimes fill it up, drive it for a while, then fill it again to see how much the real world mpg is (miles I drove between fill ups divided by gallons used for the 2nd fill up). I did that with EV's (charge to 80%, drive a bit, then charge to 80% again) to see the real world miles/kWh I'd get (something that's not even published for EV's, they use a fake metric called MPGe that's about as contrived as the lies from my ex-mother-in-law). That's part of the math on whether or not to get an EV (the gas savings is real, but only if you drive enough miles charged from home for the gas savings to add up more than the costs of owning an EV).
I may be overly cautious, but I’m not sure he should even be recharging it. I think these lithium batteries have the potential to be dangerous and bypassing, or lower, security of charging sounds reckless.