It’s a battery pack without the fancy presentation. Additionally, it does not have a warranty or perhaps have a shorter duration unlike genuine Black and Decker batteries which usually has a 3 year unlimited warranty. You can also get them in enhanced version, maybe twice as large and last two times as much. Or something that uses a different kind of battery cell like Nimh which can hold more charge than NiCad with the same size of battery cell.
Lithium Ion is a very good kind of battery cell, it can hold up to six times a NiCad can keep with same size of battery cell. If you are going to make a Li-Ion battery with the same standards as the NiCad, you’ll be able to have it 6 times smaller overall body size than the NiCad. What you get is a really compact battery that can probably fit easily on your jeans pocket.Another option in choosing a battery is the kind of cell used. For instance, a Lithium Ion Cell can hold up to six times a NiCad Cell can hold with the same volume of battery cell. So, having a Lithium Ion battery can make your cordless drill a lot smaller in size which is ideal in doing work in a restricted space.
You must also inspect the craftsmanship of the battery before buying. By visual inspection, look at the quality of workmanship, by looking at the item you can already tell if it’s made of low quality material, check for cracks and any tale tell of poor workmanship. Second is, even if it’s only a replacement it should still have a guarantee. If it breaks easily they should change it or allow you to refund the money.