Adding weight to an ev for the purpose of lovering the CG is as bad as putting lead in
the nose of a model aeroplane to move the CG forward.
Li-ion batteries with lead or steel around them will get you the same Wh/pound as lead
acid, if you aim for the same weight. You would pay $$$ for small improvements in
range and your acceleration would be as good, or bad, as before.
Lowering suspension and using stiffer springs would be much better, if possible.
The most important mass in a small ev is you! so lowering you seat, or throw away the
seat cushion, to to ride 4 or 5 inches lower will make a big difference.
Not familiar with the Sparrow, I have however tried all three things on another smal 3
wheeler: It used to do left turns on 2 wheels if I went faster than 25 mph. Now the
the only thing that happens is that the rear wheels skid if I push it to hard. Things
might be different with a very light battery pack, but try everything else before you
add weight.
