[macanaw]

There seems to be a lot of different assumptions regarding the weight difference on the a123's vs Li-ion. I have the cells from the dewalt packs and here are the weights on a calibrated scale.

a123 4600 mha 2s2p - 10.6
Fromeco 5200 mha 2s2p - 7.2

Difference being 3.4 oz

Add the weight of regulators and your about 1.5 oz difference in weight (depending on what regulators you choose).

Be careful when looking at weights published by manufacturers as they often don't include wires and deans connectors in their published weights.

David