Product Information
Rechargeable Nickel-Metal-Hydride
Button Cells
55625 603 059 3 / V 250 H SK SC PCBD Page 1 / 2
System highlights of Ni-MH Button Cells – Robust Family –
from VARTA Microbattery:
Excellent overcharge capability due to patented GCE-Electrode
Low self-discharge of 20% at RT after 1 year
Flat and stable discharge voltage
Long life – typical 500 full cycles
Slim design
Wide temperature range
- Storage: -40˚C up to +65˚C
- Discharge: -20˚C up to +65˚C
- Charge 0˚C up to +65˚C
Key features:
Good recovery characteristics after long storage period and deep
discharge
Sealed rechargeable Ni-MH Button Cells from VARTA Microbattery can
be operated in any position
The cells complete the manufacturing process in a charged state
Because of time and temperature depending self- discharge, the state of
charge upon receipt can not be precisely defined.
Before use, therefore, sealed Ni-MH cells should be recharged.
Main Applications:
RTC-Backup
Memory-Backup
Sensor Network Supply
Quality – Made in Germany
Manufactured on highly automated lines
Direct replacement for Ni-Cd
No memory effect
0% lead, 0% mercury, and 0 % cadmium
All cells have built in safety vent for security in abuse conditions
UL recognition under file BBET2.MH13654
ISO 9000 certified for design and manufacture of rechargeable mass
type cells and batteries.
Conformity to requirements of ISO 9001
VARTA Microbattery is a leader of Ni-MH Button Cell technology and
received several ecological and industry awards
are in line with ROHS (in accordance to EU directive 2002/95/EC). They
do not contain the hazardous substances Hg, Cd, Pb, Cr6+, PBBs, PBDEs,
as in ROHS, with Cd <100 ppm and the others >1000 ppm
Electrical characteristics*:
Nominal Voltage: 3.6 V
Typical Capacity: 250 mAh
Maximum Discharge current: 480 mA cont.
*See cell datasheet for further details
Designation System for Battery Assemblies
3 / V 250 H SK SC PCBD
Number of cells
Cell type
Configuration
Insulation
Connection
Physical characteristics:
Diameter: 26.8 mm
Height: 20.5 mm
Typical weight: 30 g
Pin Distance (P): 10.0 mm
Length (L): 20.5 mm
Pin: 1.0 mm x 0.25mm
L
P
+
Pin out
www.varta-microbattery.com
VARTA Microbattery GmbH
Daimlerstraße 1
73479 Ellwangen / Germany
Tel. + 49 79 61 / 921 – 0
email: contact.varta-microbattery.com
www.varta-microbattery.com
Rechargeable Nickel-Metal-Hydride
Button Cells
55625 603 059 3 / V 250 H SK SC PCBD Page 2 / 2
PROPER USE AND HANDLING
Charging
Extended charging outside specified temperature ranges may have an adverse effect on cell life. Also permanent charging
exceeding the limits of specified temperature ranges may reduce the battery life. The maximum life is achieved,
when charging at an average temperature of +20 to +30˚C.
Discharging
The specified temperature range is from -20 to +60˚C on discharge. Repeated discharge at the extreme temperatures may
affect battery life. In all application do not deep-discharge (< 0.6 V / cell) our Ni-MH cells and batteries.
Life Expectancy in Long-term use
Batteries are chemical products involving chemical reactions. Hence capacity and voltage will decrease over long time use as
well as during long-term storage capacity and voltage will drop. Typically, a battery will last 5 years or 1000 IEC cycles, if
used under recommended conditions and not overdischarged or overcharged. However, non-observance of recommended
conditions concerning storage, charging, discharging, temperature and other factors during use can lead to shortened life
expectancy of products and deterioration of performance.
Severe use applications
Short term use of Ni-MH batteries outside specified ranges maybe possible. Please consult us, if such a requirement exists.
SAFETY GUIDELINES
Keep out the reach of children. If
swallowed, contact a physician at once
Do not incinerate or mutilate, may burst
or release toxic materials
Do not short circuit, may cause burns
Do not deep-discharge into reserve
Do not solder on the battery directly (use
our tagged versions)
Restrict charging current and time to
the recommended value
Observe charging temperature:
0 to +65˚C / +85˚C
Battery compartment should provide
sufficient space for battery to expand in a
case of abuse
Either battery compartment or battery
connector should have a design that
makes it impossible to place the battery in
reverse polarity
Equipment intended for use by children
should have tamper-proof battery
compartment
Battery of different electrochemical
system, grades, or brands should not be
mixed
Battery disposal method should be in
accordance with local and state
regulations
Please refer to our material safety
datasheets as supporting documents
DESIGN INFORMATION
Discharge over temperature at 0.2CA Discharge at various loads
Cycling Charge
Overcharge
Typical discharge characteristic @ room temperature
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
0 50 100 150 200 250 300
Capacity (mAh)
Voltage (V)
Start with charge 0.1CA/16h
2CA 1CA 0.5CA
0.2CA
Charging curves with 0.5CA @ various temperatures
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
0 0.5 1 1.5 2 2.5 3
t [h]
Voltage [V]
0degC
10degC
20degC
30degC
45degC
60degC
85degC
Start with discharged cells @ 20degC, then 5h tempering in ambient temperature
1C = 240mAh
0
50
100
150
200
250
300
350
0 50 100 150 200 250 300 350
Cycles
Capacity [mAh]
Charge efficiency with 0.5CA/2.5h @ various temperatures
Discharging with 0.2CA/1V @ 20degC
0.90
1.00
1.10
1.20
1.30
1.40
1.50
0 50 100 150 200 250
0.2CA Capacity [mAh]
Voltage [V]
with charging @ 0degC
with charging @ 10degC
with charging @ 20degC
with charging @ 30degC
with charging @ 45degC
with charging @ 60degC
with charging @ 85degC
5h tempering @ 20degC before discharging
Charging temperature: 85degC 60degC 45degC other
Continuous overcharge @ room temperature
0
50
100
150
200
250
300
350
0 5 10 15 20 25 30 35 40
Month
Capacity [mAh]
0.5CA
0.2CA
0.1CA
All data are related to single cell
Characteristics.
