Batteries are both a blessing and a curse.
First, there is a definite difference in batteries. Even, staying within the same parent company, and using the correct chargers, I didn't get near the life from "Firestorm" as I do from "DeWalt." In a similar manner, those who have tried the very cheap imports have noted an almost 'one time use' to the batteries.
As for "new" vs. "rebuilt," the batteries I had rebuilt at Batteries Plus seem to hold up nearly as well as new batteries ... and at half the cost.
Some of this difference may be the thermocouples some batteries have built into them. Even more of the difference is likely to be in the chargers.
Twice, with different makes, I have had batteries ruined by faulty chargers. Chargers do fail. Sometimes they fail in a spectacular and obvious way, with smoke and glowing contacts. Other times, they simply cook a few batteries until you notice a pattern...
Last, I am beginning to wonder if the reduced life I seem to be getting is the fault of the tool itself. Bad bearings or worn brushes? I can't really say.
What I can say is that I have become more aware of the limits to cordless tools - and have returned to corded tools, saving the batteries for special circumstances. I've certainly canceled plans to purchase additional types of cordless tools.
Batteries may be fine for vacuums and drills ... but I'm sticking with my corded angle grinder and band saw. Even with the drill and vacuum, I am keeping corded tools on hand.
[This message has been edited by renosteinke (edited 02-23-2007).]
