Spot welder to rebuild e-bike battery

Posted on Wed 23rd, September 2020

• #1

GreatSince78

Hi All, I’ve been sinking deeper and deeper into an ebike battery pack rebuild rabbit hole. I’ve diagnosed the problem and am now ready to replace a few of the cells, but to join them properly I need a spot welder, so does anyone have one I could use briefly please? I imagine it’d be easier to bring the battery pack to you, but please let me know if anyone has access to one, as I’m really keen my Mum back on the road, cheers Kev.
• #2

PhilDAS in reply to @GreatSince78

Is warranty not an option?
• #3

psg1ben

This is something I've been interested in doing myself. Let us know how it goes.
• #4

Dogs in reply to @psg1ben

You're not allowed an E bike for at least another 10 years.
• #5

GreatSince78 in reply to @PhilDAS

Alright Phil, unfortunately the ebike is well out of warranty, about 4 years old now. Will be a shame if I can’t fix the battery pack as it’s a decent Giant model and in good nick otherwise.
• #6

psg1ben

Chosen your replacement cells yet?
I think Samsung are the go-to
• #7

GreatSince78 in reply to @psg1ben

alright Benson, yeah already replaced the 3 dodgy cells, the remaining 37 were fine, but pack still doesn’t seem to be charging, have a feeling the battery management system is knackered, but not sure how to tell.
• #8

psg1ben

Any updates? Buggered BMS?

Also, what spot welder was used in the end?

Any pictures of the process?

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