Testing of gel-electrolyte batteries for wheelchairs.

A simple test rig was developed to measure the capacity of the lead-acid gel-electrolyte batteries used to power wheelchairs. Results of 166 tests revealed a wide scatter of battery life with different users and also showed that, in many cases, the two batteries used in a wheelchair became unequal in charge capacity after some time in use. It is recommended that pairs of batteries should be charged in series to overcome this problem.