Yamaha JW-II Service Manual page 31

Battery
120
100
80
60
40
20
0
0 10 20
Storage time
Charging: 0.1 C × 16 h
Discharging: 1 C (E.V.-1.0 V)
Storage temperature: 0.25, 40°C
0° C
25°C
40°C
30 40 50 60
(days)
Battery Construction and
Storing the battery
When nickel hydrogen batteries are stored,
they self-discharge, so that accumulated en-
ergy is lost and the battery capacity decreases.
The amount of self-discharging is affected by
the temperature under which the battery is
stored, and storing the battery at high tempera-
tures causes self-discharging to take place at a
faster rate. Also, the battery is provided with a
control device that controls the remaining bat-
tery power, and this adds to the amount of
power lost through self-discharging. If these
two forms of consumption do not cause the bat-
tery to reach a deeply discharged level, how-
ever (the voltage is around 24 V or less with no
load), the battery can be returned to its original
state by charging it. Please be aware that, if the
battery is stored for a long period of time under
high temperatures, the material from which it is
constructed gradually deteriorates, adversely
affecting the performance of the battery.
NOTE:
•
If the battery is to be stored for a long period of
time, we recommend storing it in a charged
state, at low temperatures (0 to 30°C).
•
The control unit monitors the amount of self-
discharging and displays the remaining ca-
pacity. Advise the customer that, if the capac-
ity display decreases when the battery is stored,
the battery should be charged once again and
then stored. (As a rule, this should be done if
the display lights for 1 to 2 seconds.)
•
If the current fuse provided as an accessory
with the battery is removed, the supply of power
to the control unit is interrupted. If the battery is
to be stored for a long period of time and cannot
be charged during that time, advise the cus-
tomer that the fuse should be removed before
storing the battery. Once the fuse has been
removed, the capacity displayed by the remain-
ing capacity gauge is reset to "0". In this case,
the display can be returned to its original state
by charging the battery.
•
If the battery discharges for a long period of
time while still connected to the wheelchair, a
small amount of battery capacity is consumed
by the wheelchair. Advise the customer that, if
the battery is to be stored, it should be re-
moved from the wheelchair, and the above
precautions should be observed.
28
Characteristics