I used two of these jump start battery packs back in my tent camping which was really handy to have back then
Since then the batteries don't hold much a charge any more so they are just taking up space here. I guess you could find a replacement battery somewhere for them - never looked...
With my multiple batteries, portable B&D VEC1093DBD 40AMP smart mode charger, and 2KW Honda generator sitting in the tail gate corner of my now all the the time I don't have much need for the jump start battery packs anymore...
Just my thoughts
Roy Ken