Power Wrench

"f86sabre" (f86sabre) 01/20/2019 at 14:29 • Filed to: Tools

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Replacing the batteries and hoping I don’t explode.

VincentMalamute-Kim > f86sabre 01/20/2019 at 14:56

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Are you spot welding the tabs onto the new batteries?

f86sabre > VincentMalamute-Kim 01/20/2019 at 15:04

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I don’t have that capability. Do you think soldering would work?

Edit: did some reading and no, not without special tools. 

BvdV - The Dutch Engineer > f86sabre 01/20/2019 at 15:04

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Generally speaking an 18650 cell should last at least a 1000 charge/discharge cycles, so they probably broke due to lack of battery management in the tool... (which bothers the battery engineer in me)

f86sabre > BvdV - The Dutch Engineer 01/20/2019 at 15:09

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That is what I was seeing online.  If you leave them in the charger they die.  I’ve only used the thing a few times.

VincentMalamute-Kim > f86sabre 01/20/2019 at 15:17

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I’ve soldered the tabs with a high watt soldering iron, sanding, and flux. Obviously don’t leave the soldering iron on the battery for very long. Face shield probably isn’t a bad idea.

Edit: to respond to your edit. I didn’t know soldering wasn’t possible. Good thing I didn’t read up on it before soldering !

Or try this for just a few parts:

BvdV - The Dutch Engineer > f86sabre 01/20/2019 at 15:20

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Yeah that sounds like a bad implementation. Have you measured the voltage of the old cells with a multimeter? Because if it happened by leaving it on the charger too long, the cells might have arrived at a voltage level above the operating range of the tool. It might be the case that the tool does have a rudimentary management on the drive side, which cuts off the cell when it gets above a certain threshold (and when it gets below a lower threshold) .

In a good implementation, the charger would be stopped once the cells are full (~ 4.2V each ), preventing cell damage.

f86sabre > VincentMalamute-Kim 01/20/2019 at 15:22

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Well, it said it could be done, but you have to be super careful.