When I dismantled the battery pad, I noticed there were spot welded on to the nickel plate on the battery terminal. This nickel plate is used to connect the batteries in series or parallel. I do not understand why copper wire was not use instead ,as copper wires are commonly use in electronic circuits. Is there any reason ? Appreciate your explanation. Regards
Mechanical stiffness, perhaps, or maybe nickel-plated is cheaper than copper as a commodity right now?
The nickel spot welds better.
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galvanic electrolysis?
Jamie
...and doesn't corrode as badly.
... and the resistance of the short bit of nickel is insignificant.
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** The resistance is what makes it spot weld nicely - but it is not entirely insignificant, if the pack is used at a high enough discharge rate.Spot welds in thin steel tend to vary in quality and some have high enough resistance to cause voltage drop and localised heating of a pack of NiCd or NiMH cells.
RC plane, car and boat enthusiasts tend to avoid them and prefer soldered, thick copper wire links between cells.
.... Phil
Spot welding copper is a PITA... (having made many type T? copper constantan TC's with and without spot welder.)
George H.
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