What's inside Makita 18v LXT BL1830B OEM and clone battery packs?

A little different to my usual (microcontroller) videos - I didn't find much information online so thought I'd add some. Want me to do more (or less!) of this kind of video? Let me know! Check out http://espruino.com and   / espruino   AvE some videos on official Makita packs. For instance this old BL1830 style battery has a board that looks suspiciously similar to the clone packs I have:    • Видео