August 2000
NICKEL METAL HYDRIDE HANDBOOK, PAGE
11
•
Discharge temperature characteristics at 1C discharge
•Discharge temperature characteristics

Storage characteristics

These characteristics include self-discharge
characteristics and restoration characteristics after
long-term storage. When batteries are left standing,
their capacity generally drops due to self-discharge,
but this is restored by charge.
•Self discharge characteristics
Self-discharge is affected by the temperature at
which the batteries are left standing and the length of
time during which they are left standing. It increases
in proportion as the temperature or the shelf-standing
time increases. Panasonic’s nickel-metal hydride
batteries have excellent self-discharge
characteristics that are comparable to those of Ni-Cd
batteries.

Cycle Life Characteristics

The cycle life of these batteries is governed by the
conditions under which they are charged and dis-
charged, temperature and other conditions of use.
Under proper conditions of use (example: IEC charge
and discharge conditions), these batteries can be
charged and discharged for more than 500 cycles.
•Cycle life characteristics

Safety

When the internal pressure of these batteries rises
due to overcharge, short-circuiting, reverse charge or
other abuse or misuse, the self-resealing safety vent
is activated to prevent battery damage. Panasonic’s
nickel-metal hydride batteries have similar safety
characteristics as Panasonic Ni-Cd batteries.
NICKEL METAL HYDRIDE BATTERIES - CONTINUED
Charge Capacity (%) (Nominal Capacity Ratio)
Voltage (V)
1.6
1.4
1.2
1.0
0.8
0 20 40 60 80 100 120 140 160
Charge : 1CmA x 1.2h
Temperature: 20˚C
Model : HHR160A
1.8
0.6
2.0
20˚C
-10˚C0˚C
Charge : 1CmA x 1.2h
Temperature: 20˚C
Discharge : Cut-off Voltage 1.0V
Model : HHR160A
120
100
80
60
40
20
0
-20 -10 0 10 20 30 40 50
Discharge Temperature (˚C)
Capacity Ratio (%)
3C
1C
Temp.: 20˚C
Ni-MH (HHR160A)
Temp.: 45˚C
Ni-Cd (P-120AS)
Storage Period (weeks)
Capacity Ratio (%)
Charge : 1CmA x 1.2h
Discharge: 1CmA to 1.0V/cell
100
90
80
70
60
50
40
3001234
Temperature : 20˚C
Model : HHR160A
Capacity Ration (%)
Number of Cycles (cycle)
120
100
80
60
40
200 100 200 300 400 500