Battery repair Kit

TJS109

Pedelecer
Sep 29, 2017
109
48
75
Glos
Hi,

I have a battery with, I think, a bank of defective cells that I would like to repair.
I am put off trying by having to weld the connecting strips to the the cells.
Then I saw this saw this kit (system) for bolting cells together.

Seems like a good system the main disadvantage being price and perhaps increased size but I would need to buy a spot welder if I did not use this.
Just wondering if anyone has any experience of using them and how well they work.


Tim
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,985
6,638
59
West Sx RH
I had an original kit about 5/6 years ago with the stainless fittings, I found contact was an issue and balance wasn't great. The compression/contact was the main issue thought they now have upgraded the kit with compression bolts to bolt the two sides together.
The improved current flow with cooper/ni plating sound better though but over all I wasn't inamoured with the kit.
End of the day they certainly can't beat a proper spot welded battery but the system is cheap enough to give it a try.

If interested I have one unopened original box kit.
Two opened used kits, all with cell holders, nuts, ss interconnectors and even copper interconnectors I made and tried. The whole lot can go for £25 + p&p.
I can post pics early next week of all the bits I have.

One still has to solder a bms and sensor wires to the battery build.
 

TJS109

Pedelecer
Sep 29, 2017
109
48
75
Glos
Hi,

I have a battery with, I think, a bank of defective cells that I would like to repair.
I am put off trying by having to weld the connecting strips to the the cells.
Then I saw this saw this kit (system) for bolting cells together.

Seems like a good system the main disadvantage being price and perhaps increased size but I would need to buy a spot welder if I did not use this.
Just wondering if anyone has any experience of using them and how well they work.


Tim
Thanks for the feedback. After reading your comments and the blurb on the website about the improvements I think I will try a new one they do seem to have made significant improvements and perhaps addressed the downsides you mentioned. Guess the first step is to take the shrink rap off and see what horrors are hidden beneath, will try that when I feel brave enough.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
4,090
1,441
I had an original kit about 5/6 years ago with the stainless fittings, I found contact was an issue and balance wasn't great. The compression/contact was the main issue thought they now have upgraded the kit with compression bolts to bolt the two sides together.
The improved current flow with cooper/ni plating sound better though but over all I wasn't inamoured with the kit.
End of the day they certainly can't beat a proper spot welded battery but the system is cheap enough to give it a try.

If interested I have one unopened original box kit.
Two opened used kits, all with cell holders, nuts, ss interconnectors and even copper interconnectors I made and tried. The whole lot can go for £25 + p&p.
I can post pics early next week of all the bits I have.

One still has to solder a bms and sensor wires to the battery build.
I've never soldered a battery pack, so that sort of kit looks tempting - using the same number of cells, would the resulting battery pack be larger in physical size than it was originally? Would one need to purchase a case with larger internal volume to accommodate it?

Assemble a second battery using a kit like this, or solder, or buy a second battery? I can't sue myself if the battery bursts into flames. Battery makers use much better welders than I can afford, which presumably will do a better job of welding strips to cells without causing damage.
 
Last edited:

TJS109

Pedelecer
Sep 29, 2017
109
48
75
Glos
I've never soldered a battery pack, so that sort of kit looks tempting - using the same number of cells, would the resulting battery pack be larger in physical size than it was originally? Would one need to purchase a case with larger internal volume to accommodate it?

Assemble a second battery using a kit like this, or solder, or buy a second battery? I can't sue myself if the battery bursts into flames. Battery makers use much better welders than I can afford, which presumably will do a better job of welding strips to cells without causing damage.
I think all the cons you mention are true. The battery must be bigger due to the width of the end caps . I am intending to use it to repair a defective battery ( still in use at the moment for short trips). The only other advantage apart from not having to do any welding is that it is easy to replace a defective cell at a later stage in the batteries life.
 
  • Like
Reactions: guerney

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,985
6,638
59
West Sx RH
It's not just the 22/23 mm width of the end caps but also the extra length the caps added, the cell with holders is 90mm long.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
4,090
1,441
It's not just the 22/23 mm width of the end caps but also the extra length the caps added, the cell with holders is 90mm long.
I'd have to make a waterproof battery case. Do you know if I need to register my VAT number to order BAKs wholesale from Fogstar?

Making my own battery pack using such a kit does appeal to me, as opposed to paying Jimmy the Battman's prices. Provided it's robust enough, and the springs and bolts are stainless steel.

The only other advantage apart from not having to do any welding is that it is easy to replace a defective cell at a later stage in the batteries life.
A good reason to use this sort of kit.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,985
6,638
59
West Sx RH
At a later stage of a cells life one is better replacing all of them, if one fails others will soon follow and a new cell/s will be proping up the bads ones so it's life will be shortened.
 
  • Informative
Reactions: guerney

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,985
6,638
59
West Sx RH
The vruzend is ok is one can 100% get full compression.