hi there.......my experience of getting called out to customers where the main supply has been turned off for some time [even just two weeks] has resulted in me fitting 2 new batteries but the answer to you question is leave the lift on charge for day or two and try the stair lift unladen and see if it goes up without stalling if this happens then you will need new batteries..............hope this helps..........paul......portsmouth/uk
paul, February 2014