Note that while the article says "soldering" the pictures show "welding", which is the typical way you create battery packs. The reasons are that the welding provides a higher temperature connection but for a shorter period of time, over all dumping less heat into the battery and potentially causing damage to the cell or triggering ignition. Also makes a higher temp connection, solder can melt when the joints get hot during use.
I got a battery welder a few years ago to repair an ebike pack and also to repair a EGO power tool battery pack, but thus far haven't used it. The ebike pack was a bunch of "packets" rather than 18650 cells, and the EGO was slightly smaller than 18650, so I need to wait for another pack to fail so I can scavenge cells from one to repair the other.
Be careful if it smells like birthday cake when you're working with lion cells, that can preclude them bursting into flames. Have a metal container nearby to drop them into for transport outdoors.
I got a battery welder a few years ago to repair an ebike pack and also to repair a EGO power tool battery pack, but thus far haven't used it. The ebike pack was a bunch of "packets" rather than 18650 cells, and the EGO was slightly smaller than 18650, so I need to wait for another pack to fail so I can scavenge cells from one to repair the other.
Be careful if it smells like birthday cake when you're working with lion cells, that can preclude them bursting into flames. Have a metal container nearby to drop them into for transport outdoors.