Why would an electric wheelchair speed up when it’s been used heavily?
A power wheelchair for the sport of power soccer uses gel batteries, and a motor controller with PWM output. The controller is programmed to give a maximum speed of 6 mph to meet game rules, but after half an hour of play, the forward speed has increased to over 6.5 mph, breaking the rules of the game.
The maximum speed of the chair is 8mph when programmed to 100%, but the programming does not change during the course of the game. What could be causing this drift in speed?
Edit- as of this evening I have measured the voltage after “warm up”, and it was actually lower than the starting point. I thought voltage increasing with warming was a great suggestion, but with an averaged output of 15 to 20 amps, and a resistance of 0.003 ohms, the battery just doesn’t heat up that much.
sometimes the programming fails. Just happens.
Journey Comfort 4 Wheelchair Cushion Size 22 x 20
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $78.95 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $78.95 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $78.95 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $78.95 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $75.35 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $95.85 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $79.99 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $95.85 |
|
|
Medline Nylex-Cover Gel Or Foam Wheelchair Cushion $95.85 |
|
|
Motorcycle Seat Gel Pad GL1800 Wheelchair Goldwing Large $89.99 |
|
|
Commander Gel Wheelchair Cushion 20×16 $29.99 |
|
|
Drive Premium Guard Gel Wheelchair Cushion – 16 x 16 x 3 inches $54.95 |
|
|
Drive Premium Guard Gel Wheelchair Cushion – 16 x 18 x 3 inches $54.95 |
|
|
Battery Desulfator Saver AGM/SLA/Gel/Wheelchair/Jetski $34.00 |
|
|
DRIVE MEDICAL BRAND NEW LARGE 22 X 18 X 3 DELUXE GEL WHEELCHAIR SEAT CUSHION $39.99 |
|
|
GEL-PALM Manual Wheelchair Gloves – New NIP- S Med L XL $34.95 |
|
|
GEL-PALM Manual Wheelchair Gloves – New NIP- S Med L XL $34.95 |
|
|
GEL-PALM Manual Wheelchair Gloves – New NIP- S Med L XL $34.95 |
|
|
GEL-PALM Manual Wheelchair Gloves – New NIP- S Med L XL $34.95 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $228.00 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $298.00 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $346.00 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $384.00 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $478.00 |
|
|
MK Scooter & Power Wheelchair Rechargeable Battery PAIR $498.00 |
|
|
Skin Protection Gel E 22x18x3 Wheelchair Seat Cushion $84.95 |
|
|
Medline Gel Foam Wheelchair Seat Pressure Cushion 18″ $36.99 |
|
|
Medline Gel Wheelchair Seat Pressure Cushion 16.5″ x 18 $36.06 |
|
|
NEW LARGE GELCO Gel G-Seat Ultra Gseat Cushion Wheelchair Office Chair Ergo Car $119.95 |
|
|
Wheelchair Gel Cushion Brand New in package 17X17 $29.99 |
|
|
Skin Protection Gel E 24″x18″x3″ Wheelchair Seat Cushion, Rated for 300 lb User $89.95 |
|
|
Gel Supreme Wheelchair Seat Cushion 3″ 24 x 18 in. $48.99 |
|
|
Foam Gel Seat Cushion for Car, Chair, Stadium, Airplane, Wheelchair $26.20 |
|
|
Lumex Gel Seat Cushion Akros DFD 811 Wheelchair 16x16x2 $72.95 |
|
|
Mason Wheelchair Cushion 18x16x3 – Model Titanium FPT-2 Gel $24.99 |
|
|
Motorcycle Seat Gel Pad Auto GL1800 Goldwing Wheelchair $59.95 |
|
|
Nova Ortho Gel Foam Cushion for 18 Inches X 16 Inches Wheelchair, Medium, 2 Inch $55.01 |
|
|
High-Density Foam Cushion with Gel Center (Great for Wheelchairs) $29.99 |
|
|
NEW GSeat MOBILITY Wheelchair Gel Cushion G seat Ultra $119.95 |
|
|
WHEELCHAIR CUSHION – HUDSON – PRESSURE Eez- GEL CUSHION $25.00 |
|
|
Yuasa NP7-12 12V 7AH Battery $17.50 NOMINAL VOLTAGE: 12V. NOMINAL CAPACITY: 20 hr. rate of 0.35A to 10.5V 7.0Ah, 10 hr. rate of 0.65A to 10.5V 6.5Ah, 15 hr. rate of 1.19A to 10.2V 5.95Ah, 1 hr. rate of 4.20A to 9.60V 4.2Ah. WEIGHT (approx.): 6.17 pounds (2.64 kgs.) ENERGY DENSITY (20 hr. rate): 1.49 WH/cubic inch (91.0 WH/liter) SPECIFIC ENERGY (20 hr. rate): 13.6 WH/pound (30 WH/kg) INTERNAL RESISTANCE OF CHARGED BATTERY: 30 millio… |
|
|
Gel Auto Seat Cushion – Encased in Micro-Suede (cocoa) (2H x 16W x 18D) $73.99 Utilizing proprietary medical wheelchair cushion GEL technology, this Gel Auto Seat Cushion is perhaps the finest Auto Seat Cushion available. A luxurious micro-suede handled zip-off cover featuring a lined non-skid vinyl bottom for secure placement encases a true pressure-free medical GEL cushion that distributes pressure evenly throughout the body and coccyx area. It even reduces temperature for… |
|
|
Water or Gel Wheelchair Cushion – Gel cushion, 18 inch X 16 1/2 inch – 1 ea $28.07 Designed to fit most standard wheelchairs, these cushions provide optimal pressure relief and comfort for all-day sitting. Both cushions work by distributing the patient’s body weight evenly. The gel cushion gives patients an especially stable feeling, because the gel is similar to a patient’s adipose tissue (fat layers). And because the gel is very thick, it minimizes leakage, even if the cushion… |
|
|
Large FIRM Tush Cush Seat Cushion – Navy $41.95 TUSH CUSH LARGE FIRM CUSHION Full Size (14 X 18″) – The Original High Quality Tush Cush is designed to relieve and prevent back pain, numb buttocks and other discomforts associated with sitting. Cutout section suspends your tailbone (coccyx) reducing pressure on your lower lumbar discs. Wedge shape (slant from the back 3″ down to 1/2″ in the front) tilts your pelvis forward to restore your spine’s… |
|
|
Contour Products Freedom Seat $23.95 Contour Products Freedom Seat Freedom Seat provides all-day comfort! Freedom Seat works to keep you comfortable as you sit. Use with any chair, even a wheelchair. High-density foam provides better support & even distribution of your body weight. Graduated edge positions hips for better alignment and posture. With soft, breathable cover for all-day comfort. The Contour Freedom Seat is made of h… |
|
|
Coccyx Gel Seat Cushion With Fleece Top 16 D x 18 W x 3 $33.85 16″ x 18″ x 3″ * Cut-out relieves pressure on the spine * 3″ High density foam with gel pad center * Reduces pressure on the tail bone and spine * Washable, navy cover with soft fleece top * Suggested HCPCS code E2601 *… |
|
|
Compatible Wheelchair Battery for Pride Mobility Jazzy 1143 $57.93 12 V 33Ah BATTERY FLAG POST TERMINALS… |
|
|
Amara Bariatric Cushion 30 x 20 x 3 (Catalog Category: Wheelchairs & Accessories / Cushions – Gel) Amara Bariatric Cushion 30 x 20 x 3… |
|
|
Extreme Orthopedic Seat Cushion $78.50 Wondergel (Intelli-gel) is the most advanced cushioning material available today. Made from an ultra-modern copolymer, Wondergel provides comfortable support while eliminating pressure points. This lets you sit hours longer in comfort. Cushions made with traditional cushioning material or memory foam create “push-back”, so that if you need to sit for more than a few minutes, you may experience dis… |
|
|
UPG UB12350 (Group U1) Battery – Universal Battery – 12V 35Ah $54.99 Battery Supersite includes the Nut and Bolt hardware to attach your cables. This state-of-the-art lead-acid battery is sealed and maintenance free and the electrolyte is fixed in absorptive fiberglass mat. The advantage of this superior design is that the battery needs no water additions, can be operated in any position, and can be used in close proximity to people and sensitive equipment. Additio… |