How do you check a used EV's battery health? / Buyer who can't get a battery reading from the seller and wants an independent check

Buyer who can't get a battery reading from the seller and wants an independent check

What people actually reported
Cheap ELM327 dongles wouldn't connect to Car Scanner
“I already tried the cheap blue ELM327 dongles and they wouldn't connect to Car Scanner at all, so I'd skip those.”
@tcarden_81
OBD app SOH estimate was way off most of the year
“I tried an OBD2 reader and app, and its SOH estimate was way off from reality for most of the year.”
@rwinfield_23
2nd gen Leaf shows capacity in dash menu; gen 1 only bars
“I daily a 2nd gen Leaf, and the 2nd gen shows capacity in a dash menu you scroll through with the steering wheel arrows.”
@glenn_tate
Questions still raised in the forum