It’s once again time for everyone’s favorite type of post! Tool battery teardowns! This week, I’ve got three seemingly identical batteries. They’ve got the same connections, the same dimensions (except height - the center one is a smaller capacity pack), and so one would expect them to be very much the same on the inside. Are they?
This is a companion discussion topic for the original entry at https://www.sevarg.net/2020/01/18/makita-and-rayovac-battery-pack/
(Comments from Blogger)
2020-03-28 by Jason Hirsch
I’m a little bummed by your bashing of the Makita pack’s engineering. When I disassemble these in compared to a variety of other manufacturers, I was incredibly pressed at the thoroughness and safety built-in. a lot of older lithium chemistry’s were and still are extremely dangerous, and those packs had to withstand quite a bit. Obviously cheaper builds nowadays cut many safeties out of the way. It’s also why it’s easier to find junk battery packs now of newer tools, because all of the good engineering has been as you said taken out.
For a lot of fun, look at the harbor freight / power packs. You can see where they appear to be made like the waltz, and in some cases there are no protections at all inside of the battery. that means if a tool shorts, the battery is going up.
2020-03-29 by Russell Graves
Part of the art of engineering is understanding what’s enough. I love a totally over-engineered widget as well as the next guy, but at some point, you pass the point of “This is adding anything useful” and cross into “This is just costing extra money.” Based on what I’ve seen in an awful lot of tool packs, the Makita’s pack is just over-engineered for the sake of over-engineering. It doesn’t add much extra strength, and it’s not like the pack is now tolerant of being run over when it wasn’t before.
It’s pretty rare to find a tool pack with the ability to cut the output, at least for a modern, lithium-designed tool. They’re almost all “always live” on the output terminals, so a short will definitely be exciting. The DeWalt 20V Max packs are like this, and they’re certainly a popular pack. Despite that, we don’t hear about DeWalt drills burning up regularly, so I’m just not that concerned about it.
2020-07-10 by Sadi Porter
You should do a teardown of this newer 6ah fake makita battery, it has better battery management and better build quality: https://www.aliexpress.com/item/33048012981.htm
2020-07-11 by Russell Graves
Send me one and I will, but I don’t own any Makita tools, so it’s not something I’m going to buy for myself.