I've got my CF8 build working and it is amazing. Will probably do a Prizm next time just for ease of installation, but this was a great learning experience.

One thing I'm curious about, but a little context first. I tried getting away without soldering to a battery using *very* sticky copper tape to keep the wires in place (never soldered to a battery before, was a little apprehensive). But I was experiencing popping on the speaker due to the unstable ground connection, so I soldered the ground and that cleaned it up quite a bit. I did leave the positive alone for a while because it was harder to get to (and I was being lazy). But it was having charging issues due to false resistance I imagine (it would quit charging too soon) and so soldered the positive as well.

Dramatic difference after that, better amperage as evidenced by the brighter LED, and consistent charging. I used the saber quite a bit this weekend and its battery was getting low. The main way I noticed this was that the sound became quieter. Eventually, I started getting popping on the speaker again. I thought perhaps that the wires on the speaker were breaking off from the solder joints or something was up with the power/ground joints on the battery again. But I tried charging it first since I had used it a lot, and I still got a consistent charge, about an hour and a half. Powered it on after that and the popping seemed to be gone.

Should popping on the speaker happen when the battery is low?