Bests & Worsts Reviews from Amazon

B&D doesn't really tell you the whole story about their batteries... In my experience, this battery has 1.5 Ah cells, and unless HPB18 to which it is compared to has 1 Ah cells (which I doubt) it cannot have 50% more capacity. 25% is more likely and it was marketed as such for a while. Adding to other review, I think I figured out number near the battery lock. First, you have manufacturing year and week along with some letters. And then there is three digit number, which tells you cell manufacturer (first digit) and capacity (two last digits). This is what I encountered: 412 - 1.2 Ah cells marked BD (most likely specifically manufactured for B&D) - usually FS18B and HPB18 batteries, but also some 244760. These cells are actually short Sub C (or 4/5 SC) and B&D puts plastic pad inside the battery, so housing has the same exterior size. 115 - 1.5 Ah cells without manufacturer identification 415 - 1.5 Ah cells marked BD 515 - 1.5 Ah cells manufactured by HANYU All these are marketed as FSXtreme, HPB18-OPE, FS18BX and 244760 421 - 2.1 Ah cells manufactured by BYD - high capacity "Silver Series" FS18SBX. BYD is actually well known Chinese battery manufacturer, nice chunk of whose shares was recently purchased by Warren Buffett.