They are crap to charge the LG G5, but should be of decent quality for whatever they are. Nice square batteries for projects, will fit great into a project box.
If they are crap, why harvest them? seems a lot of hassle for a crap battery. I could understand it if it were an 18650, maybe it is? These have been lying dormant so long they might be useless/unchargable anyway (fallen below min voltage) - particularly if they were already crap.
I would harvest the batteries for projects... Maybe for Arduino or an IoT project...
Good for very fancy paper weight.
Niche, but still a deal.