I've put together a 2-cell pack using a pair of 18650 cells. Mine are pcb-protected so they are about 69mm long, and most sleds only fit unprotected cells that are 66mm. I tried to mod a smaller sled, but results have not been reliable.
I need to wire a pair in series, then 2 pair in parallel to get longer (7-hour) 7.4v output. Looking around, the Keystone 1048
is made for the longer cells, and I'm leaning toward building a 4-cell pack using them. Contacts should make for easy soldering, but I'll need to find a way to get the two sleds mated/enclosed.Battery Space
has holders for 18650 cells that would keep them solidly connected, but they have no contacts. Has anyone tried to construct a multiple-cell battery holder from spare parts? Any advice from folks with previous experience (good or bad) would be appreciated. Thanks.