Alternative to the laptop battery salvage.

[psychephylax]

I know some people recover 18650 cells out of laptop batteries to use. I found an alternative source for these. A lot of VoIP cable modems have battery backup in case of a power outage so you can still use the phone.

Those cells usually sell on eBay for 10-15$ and contain 18650 cells. They are not button top, and must be processed similar to the laptop batteries.