Bad weld from spotwelder

Batteries, Chargers, and Battery Management Systems.
Post Reply
kocetoMR   10 W

10 W
Posts: 75
Joined: Jun 13 2016 3:19pm

Bad weld from spotwelder

Post by kocetoMR » Oct 16 2020 1:23pm

20201016_210956.jpg
spot welder
20201016_210956.jpg (482.52 KiB) Viewed 233 times
one side is good ,other side is poor.
Spot welder is from 2P2S supercap 2.8V.Check the cable and connection,they are good.
:roll: :roll:
What can be the problem?

kocetoMR   10 W

10 W
Posts: 75
Joined: Jun 13 2016 3:19pm

Re: Bad weld from spotwelder

Post by kocetoMR » Oct 16 2020 1:29pm

1602872910529.jpg
capacitors
1602872910529.jpg (93.5 KiB) Viewed 231 times

kdog   10 kW

10 kW
Posts: 694
Joined: Feb 02 2014 9:22pm
Location: hobart, tasmania

Re: Bad weld from spotwelder

Post by kdog » Oct 16 2020 5:38pm

Minor variation in electrode pressure or electrode tip shape would be my main guess in that order. My spotwelder is AC so I'm not sure about DC, but welders pay attention to polarity of their workpiece, try swapping tip polarity and see if it reverses. Can't think of anything else ottomh.

kdog   10 kW

10 kW
Posts: 694
Joined: Feb 02 2014 9:22pm
Location: hobart, tasmania

Re: Bad weld from spotwelder

Post by kdog » Oct 16 2020 5:41pm

Have you tried actually spotwelding some nickel?looks like you're just hitting the can there.

kocetoMR   10 W

10 W
Posts: 75
Joined: Jun 13 2016 3:19pm

Re: Bad weld from spotwelder

Post by kocetoMR » Oct 17 2020 9:27am

20201017_172343.jpg
every time when start weld needle neet luke like this
20201017_172343.jpg (215.16 KiB) Viewed 182 times
every time when start weld needle neet luke like this

User avatar
spinningmagnets   100 GW

100 GW
Posts: 11869
Joined: Dec 21 2007 10:27pm
Location: Ft Riley, NE Kansas

Re: Bad weld from spotwelder

Post by spinningmagnets » Oct 17 2020 11:53am

Get some old bad cells, even disposable D cells will work. Use some nickel scrap and weld onto the scrap batteries. The longer path will add more resistance.

Nickel bus, and nickel-plated steel are very good for the parallel connections. For the series, I like the nickel-sandwich method.

viewtopic.php?f=14&t=108006

Image

kocetoMR   10 W

10 W
Posts: 75
Joined: Jun 13 2016 3:19pm

Re: Bad weld from spotwelder

Post by kocetoMR » Oct 17 2020 1:48pm

20201017_213659.jpg
cooper strip
20201017_213659.jpg (475.22 KiB) Viewed 164 times
i use sandwich method in many battery pack.In my country copper is with high %gold and is difficult to weld direct to cell with sandwich method.

Post Reply