QM-7 SERIES SERVICE MANUAL
PAGE 3.1
JANUARY 2012
SUNRISE MEDICAL
Section 3
Batteries should last an average of 1 to 1.5 years.
Listed below are some Factors that may effect battery performance:
•
Maintenance - Poor maintenance.
•
Charging - Improper charging shortens battery life.
•
Chair Components - Malfunctioning electronics, bad motors, electric brakes, and
corroded wiring are also capable of degrading the battery performance.
No power: Battery Diagnostics
VR2 Troubleshooting
Note: For access to batteries, refer to beginning of Section 7 (Battery Access/ removal)
A routine test of deep-cycle wheelchair batteries should follow these guidelines:
1. Never replace just one battery at a time. This will create an imbalance when charging and
ultimately damage both batteries.
2. Check batteries for a voltage difference. A voltage difference of more than .4 volts D.C. is a
good indicator of a bad battery.
3. Voltage test - A dead battery cannot be effectively tested, yet many people mistakenly try to do
just that.
Any battery that reads 11.0 volts or less is technically dead.
To perform any testing, especially a load test:
A. Batteries must be charged
B. The top charge must be taken from fully charged batteries if charge rate has just
fi
nished.
Battery Servicing and Replacement
Note: The voltmeters on load testers are not accurate enough to establish a state of charge.
•
Load Test
- This test can only be done on fully charged batteries and can only diagnose one
type of problem, (an internal short.)
•
Capacity/Discharge Test
- This is the only accurate way to test a deep-cycle battery for adequate
running time. The problem with this test is that it is time consuming.
•
Current / Voltage check
with a regular interval check
- Another way of truly knowing how much
time your battery will last, but it is also time consuming.
Battery Tests
