Mass of individual parts (kg):
Part Mass (kg)
lower frame 11.5
upper frame 3.26
Arm rest(No 1) 1.01
Arm rest(No 2) 0.97
Wheel Assy (No 1) 9.86
Wheel Assy (No 2) 9.81
Battery (No 1) 15
Battery & Controller & cables 16
Back rest 2.56
Total Mass 73.27
If light weight batteries (LiFePo4) - 7kg and 8kg[inc cables and controller]) the heaviest part becomes the lower frame at 11.5kg - if the footrest is unbolted it is likely to become around 10kg.
If the lower frame was re-manufactured without the extra bits of weld that was added due to it essentially being used as a welding practice project it would likely be 10kg including the footrest.
The lower frame will be re-manufactured once the rest of the project has been completed.
The reason I've chosen 10kg as a maximum mass is because that is the maximum mass that should be lifted from the height of the chair (as it is dismantled) to the approximate height of a car boot (assuming the car boot is between knuckle and elbow height) for a woman according to the recommendations of the HSE (Health and Safety Executive) http://www.hse.gov.uk/pubns/indg143.pdf
(page 8). For a man the relevant mass is 15kg.
For anything above 10kg (15kg for a man) it is recommended that a more detailed Health and Safety Assessment is carried out.
A maximum mass of 10kg should be achievable (although new batteries will need to be purchased).