I'm thinking of going into business refilling existing packs myself. Here's a taster of the eBay description I'm planning to use.
Critique away
' I will refill your battery pack with any old useless, past their date, generic batteries that are lying around in my shed.
No BMS and really shoddy soldering, will ensure your pack will either not work in the first place, blow up in your face when you're least expecting it, or burn down your entire house.
Just send me your old pack, and I will carry out the work and send you a pack that is worse than the one you sent me.
ABSOLUTELY ZERO WARRANTY GIVEN DUE TO THE HIGH LIABILITY
*** WARNING... Please keep a fire extinguisher handy at all times *** '