Well, you get what you pay for. I've sampled a few batteries from Harbor Freight. While most of their tools actually are quite usable, their batteries have left much to be desired.

Take a look at
http://i2.photobucket.com/albums/y12/RARECJ8/Hazard-Fraught.jpg
http://i2.photobucket.com/albums/y12/RARECJ8/HF4.jpg
http://i2.photobucket.com/albums/y12/RARECJ8/HF3.jpg
http://i2.photobucket.com/albums/y12/RARECJ8/HF5.jpg
- though many things they sell aren't *that* bad, some things really are that bad... But it's fairly humorous.

Chicago Electric PP3 NiCd - One cell has really bad self discharge and thus is useless. I have a Panasonic branded NiCd that's much older than this whose cells are still in good shape even after many more charge/discharge cycles. The bad cell cannot be recharged.

Chicago Electric NiCd D-cells - These 1500mAH cells, I have 4. One of them will completely self discharge in one day of nonuse.

Thunderbolt Magnum PP3 Alkaline - Some of the cells internally have really poor power retention and expire well before the expiration date

Chicago Electric NiMH AA-cells - These initially were OK but cannot be quick charged. They get hot quickly and degrade quickly after that. I have a few Duracell branded NiMH that survive the same charger after many cycles and retain their low internal resistance.

Stay away from Harbor Freight batteries. I'm thinking about buying Harbor Freight's Lithium Ion drill to replace my Ryobi which has bad NiCd cells now, but this history is deterring me... But lithium ion batteries tend to be better protected...