I wouldnt bother with ebay batts, and deffinately not sports packs assembled with foil connecting the cells. Head over to Promatchracing or SMC and pickup some decent nimh packs, or there is always cheapbatterypacks.com- they have some good stuff for lower prices.
"All-Battery" as a whole isn't to bad, their website has the best selection for open cells and hard to acquire rechargables.
I do not know anything about these packs though ?
I retired from RC, now life is all about guns and long range shooting.