A rechargeable power tool battery is rebuilt by replacing its spent cells with an array of replacement cells in which connections are made by conductive connectors, ends of which are clamped by bent-over arms of star-shaped malleable metal grips, the hubs of which are spot welded to cell terminals by the replacement cell supplier. Replacement cells can be supplied in pairs with the positive terminal of one cell of the pair permanently connected to the negative terminal of the other cell of the pair and with the other positive and negative terminals each provided with a spot-welded star-shaped grip.