Assault On Battery

Give your old apple laptop’s battery a fresh charge.

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My plan was to recell the powerBook battery, as a rechargeable battery that doesn’t recharge is just a plastic brick and I’d have to pay someone to recycle it. Recelling a battery requires opening it up and replacing the depleted cells inside. The battery for my PowerBook 520 is part number M1906, which is a 9.6V 1,800mAh nickel-metal hydride pack. NiMH batteries have 1.2V per cell, which means that inside the grey plastic slab there must be eight separate cells, connected in series.

Laying out some ordinary rechargeables on top of the M1906, it looked like eight AA batteries should fit. Modern AA rechargeables have capacities up to 2,400mAh and are guaranteed for five years. I could refit my PowerBook battery with eight for £14, and it should have 33% better life than when new!

First I needed to get inside the battery case. This was not easy. There were no screws or clips; the case was heat-welded firmly shut. The slowest speed on my Dremel tool is 5,000rpm and would melt the plastic, so the neatest option to cut my way in was to painstakingly score the seam with a sharp knife, over and over again. When I was a child, my dad would always be standing over me saying “cut away from you!” Now I’m an adult, the voice in my head is my son’s, saying “Dad, remember what you always say – cut away from you!” Yet still I ended up taking risks to hold the battery more comfortably, and then the knife would slip and miss my thumb by the width of an atom, and for the next 10 minutes I’d try to be more careful.

Terminal Confusion