I saw something in the HK listing that I can't figure out. It is copper and seems to be a tip for a soldering iron but it looks like a hammer and seems to have hollow cups in the head. I also seems to have something to do with attaching plugs to battery wires.

My best guess is the cup holds molten solder, the iron keeps it hot, and you pour into a wire end. Am I close.

Sounds like the device they use to solder round cells end to end.

Gord.

If it looks like the below, it is a copy of Charile White's hammerhead soldering tip. I just used mine a few minutes ago to replace an A123 2300 in a duff pack. I have references in the Ampeer back to June of 1999.

It is for soldering two cells in series. Tin the end of each cell (one positive, one negative end); put the cells in a "v" channel, and far enough apart to get the tool between them. Push the cells into the tool until the solder on each melts, the QUICKLY remove the tool and push the cells together. The molten solder will cool and join the two cells with the least amount of resistance possible. Just dont push too hard/fast or the solder will splatter, and get drops of solder almost anywhere.

Les

Anyone know of a video of the tools use? I am pretty dense and don't get it. By cell, do you mean the common AA,AAA type? I don't do much soldering but my sense is the solder would harden before I could make a connection. I have enough trouble just adding plugs to lipos.

Not a video, but shows some Panasonic 2000mAh NiMH being soldered into 3s to form a 6S pack. Trough lets the top cell slide onto the bottom cell after hammerhead tip is removed from between two of the cells. Completed 9-cell pack shown as well.

If you try to use this (it takes a bit of practice and skill) be sure to have the ends of the cell very clean with a coat of flux on them before heating and soldering together. Note: heat that positive end of a Nixx cell to long and you destroy the inner seal at the positive terminal which will cause the cell to die a slow death. If a NiCad cell and you destroy the seal, you can also start the so called "black wire" type corrosion which is sometimes found in NiCad powered equipment which has had a cell rupture or leakage.

It is also best to put the V-Shaped channel vertical.
So, the excess solder does not run sideways.

But I still prefer connecting the cells with a 0.3mm copper strip, and bending them together afterwards.
This process is easier, needs less energy, Quality check is easier, one can attach balancing wires to the copper strip in case of LiIon cells, and one will not get a broken solder joint because of a hard landing.

All very true for sure. Remember that is a 1999 photo, no balancing. All my A123 packs are strapped with balance wires on the straps. Straps are either braided wire or the ones spot welled onto the A123 2300mAh cells.