I doubt the PCBs weigh too much. There's also a variance in battery weights. Testing it real quick my Li-ion AAAs weight 9g, NiCd 10g, and Alkaline 12g. There's

I doubt the PCBs weigh too much. There's also a variance in battery weights. Testing it real quick my Li-ion AAAs weight 9g, NiCd 10g, and Alkaline 12g. There's also some Li-ions with built-in USB recharging circuits that I don't know how they effect the weight. So better make sure they remove the batteries too. And who knows about the variances in internals they've done to the TI-84 in its 20 years of production.