Lano

I’m having an unusual problem building some new IP3600 battery packs. For reference I use a Weller iron with an 800 degree large chisel tip, flux and standard 60/40 solder.

When I try and tin the negative end of the battery I can’t get the solder to flow properly. Even with a HOT iron it wants to solidify almost immediately. It is then nearly impossible to get the solder to properly flow once I put on the battery bar. I ONLY have this problem on the negative side.

Any help would be appreciated.

Mark G

iTrader: (7)

Did u rough up the cell's with a dremal or sand paper ?? you want to make sure it has some serface to contact to. Also tin the cell,and battrie bar too before you try again. also when you did all that and ready to soddier put some on ur tip and it will go a bit quicker.
Hope that stuff helps
-Mark

Lano

Yep, I roughed up the cell with emory, added solder to the tip, all the normal stuff. It's as if the cell is intantly absorbing the heat.

I gave up tinning the cells (negative side) and just tinned the battery bar. This worked but I'm worried about the strength of the joint.

Mark G

iTrader: (7)

well one way to test that is to drop it on ur table like 2 inches in the air. do that 3 times and if it doesnt break than ur good.

SPC

Try using a quality liquid flux, like Trinity's solder flux. After cleaning/sanding the cell ends place a small drop of flux on the cells, then add another small drop to the top of the battery bars. Place the bars on the cells and with a BB sized drop of melted solder on the iron tip place the soldering iron tip to the bar. The solder should nearly instantly flow around the bar to the cell. Do not tin the cell ends. Tinning adds additional lead between the joint and increases resistance.

Lano

Mark G and SPC, thanks I'll give it a try.