We want to thank the wonderful people at Richardson Products who brought us the Powertech Sigma. Becky is free now to work and play as hard and as long as she wants during the day without worry about her vent needing batteries. Prior to using the converter, we used 3 batteries a day and had to make sure we always had extra with us and had to make sure we were close to our extra battery or carry it around. We had to recharge three batteries every night (the insurance doesn’t reimburse for the charges either). It seemed that the battery was always running out at the most inopportune moments, often interfering with a family outing. But all of that has changed now. With the PowerTech Sigma, we go all day with no worries about batteries, no worries about getting too far away from our spare battery. We’re enjoying the freedom. The pictures you see show our busy little girl as we played at home, went to school, went in the van to a doctor’s appointment, and came home to enjoy the outdoor fun with friends. At the end of our busy day, Becky’s joystick still showed the charge almost complete. We lost only 1 or 2 bars on the wheelchair after a whole day ( which typically starts at 7 am and concludes at 9pm) of busy activity and continuous ventilator use. Since we don’t need the vent tray now for the battery, we are planning on eliminating the ventilator tray on Becky’s new wheelchair. We absolutely love the Sigma! Thank you again!