Have seen a lot of used Sovereign rechargeable battery packs on EBay, Like everyone else was curious so I got three of these rechargeable packs at very low prices. Description from the seller held a full charge last time used, LOL kind of like saying the use car for sale was only driven by the little old lady to church. I didn't expect much so here's the results. First my rechargeable pack as a benchmark was made from AAA batteries run time in the field 12.5 Hours. The best used rechargeable battery off of EBay had a run time of 10 hours, not too bad as a backup and even though had the ear tabs broken off replaced with the one from an old battery pack. The second place battery had a time of 4 hours, which not enough for a backup. The third one had a run time of 3.5 hours not really good for a backup. At the local Batteries Are Us store the guy behind the counter told me, no problem, he had the batteries I needed and would wire them in the same series. This was a simple and easy fix until I asked his price, which was $96.00 plus tax. I decided for other options.