I have had my batteries for about 4 years now. I bought one used and one new and have had absolutely no problems with them the whole time. The only time i could remember is when i was trying to charge them and it was -25C. But that was just because it was so cold. Other than that, I'm extremely happy with them. I use them in 36v recip. saw and circular saw.
I have 9.6V, 12V 14.4V and 36V Cordless tools. Al of them at one time or another have had a battery or two reach fully discharged,but have taken a recharged except the most expensive battery of them all. Son in law used flashlight and left it on and didn't put battery on charger. Battery is no longer able to take charge, I even tried freezing it (battery had only about 6-9 charges on it) other battery works fine, it has now had about 25 or so charge cycles on it and runs strong. Just remember when the tool stops or the light goes dim remove from tool and put on or near charger.
Read some negative reports on the 36 volt batteries. My experience is - I purchased the $800 36 volt kit in July 2006. It's now December 2014 and the original Ni-Cad batteries are still working - although not quite as long as the used to - but exceptional life (8 yrs) for Ni-Cads. I plan to buy Li-Ion replacements - expensive, but I like the power & runtime of the 36 volt system.
This company is fantastic. I have purchased several reconditioned items and have not had a problem. The products are just like new only you pay a lot less! Do not hesitate to purchase from Reconditioned Tools.