Rechargeable Button Cells NiMH Sales Program and Technical Handbook www.varta-microbattery.
Rechargeable Button Cells CONTENT 1. GENERAL INFORMATION 3–8 1.1 1.2 Product families General Design and Application Criteria 4–6 7 2. ASSORTMENT V...H(T) ROBUST (85) 9 – 24 2.1 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.
1. GENERAL INFORMATION VARTA Microbattery is a leading firm in the field of batteries and provides professional support for customers with engineered design-in applications worldwide. Quality, reliability, high performance and customer satisfaction are the main reasons for our leading position in the market.
Rechargeable Button Cells 1.1 PRODUCT FAMILIES Four button cell families with specific strengths and features provide the ideal battery solution for any application. Each family has its speciality to provide optimum solution for dedicated application areas. Product Overview Type Designation Type No. Voltage (V) Capacity (mAh) Diameter (mm) Height (mm) 3.1 5.35 6.0 5.85 7.4 6.7 7.
Capacity Range From V 6 HR to V 600 HRT, from 6 mAh up to 600 mAh – VARTA provides a full programme of rechargeable button cells for all performance requirements. Quality – Made in Germany ■ Manufactured on highly automated lines ■ Direct replacement for NiCd ■ No memory effect ■ 0% lead, 0% mercury and 0% cadmium ■ UL Recognition under file BBET2.MH13654 V…H V…HT robust robust85C High performance button cell with superior overcharge stability and discharge currents ≤ 2 CA.
Rechargeable Button Cells V…HR V…HRT powerful powerful85C High rate button cell with superior load capability for dis-charge currents up to 5 CA. Based on foam electrode technology, temperature range -20 to +65°C. High rate and high temperature button cell with superior load capability for discharge currents up to 5 CA at high temperature. Based on foam electrode technology, temperature range -20 to +85°C.
1.2 GENERAL DESIGN AND APPLICATION CRITERIA The choice of the most suitable cells or battery types is exclusively related to the type of application and the operating conditions. The most important criteria for selection are as follows: ■ Type of operation of the cell, i.e.
Rechargeable Button Cells
2.
Rechargeable Button Cells 2.1 C ONSTRUCTION AND ELECTROCHEMICAL PROCESSES OF NIMH BUTTON CELLS A special sealing design maximizes the diffusion path and guarantees optimal protection against leakage. The cup of the casing acts as the positive terminal and the lid as the negative terminal. The punched positive sign on the cell is used as a safety device which opens at predetermined internal pressure, in case of gross abuse. Some cells are interchangeable with 1.5 V primary cells of identical dimensions.
2.2 FEATURES V…H(T) ROBUST (85) ■ Cells with typical capacities from 16 up to 380 mAh ■ Nominal cell voltage 1.2 V ■ Wide operating temperature range ■ Built-in safety device ■ UL Recognition ■ Limited fast charge possible (within 3 h at 0.
Rechargeable Button Cells 2.3 N IMH BUTTON CELL BATTERIES FOR BRIDGING, HOT SWAP AND MEMORY PROTECTION APPLICATIONS Bridging Batteries Bridging batteries from VARTA Microbattery are optimised in small size and provide high power output for bridging mobile computers e.g. during main battery change. Bridging batteries temporary take over the supply of DRAM and other chips in notebooks, PCs, handhelds, calculators, etc.
2.4 NIMH BUTTON CELL BATTERIES FOR MEMORY PROTECTION Typical Application Weight (g) Height without pins (mm) Width (mm) Length (mm) ■ PCs ■ Notebooks ■ Hi-Fi Systems ■ Car stereo, etc. Typical capacity (mAh) Nominal voltage (V) Order No. Type No. of cells These batteries are designed for memory backup (MBU) and support to RTC (Real Time Clock) in various electronic applications. NiMH Button Cell Batteries in the charged state are suitable for wave soldering (tmax. = 10 sec., Tmax. = 265°C).
Rechargeable Button Cells 2.5 NIMH BUTTON CELL BATTERIES FOR BRIDGING APPLICATIONS Bridging Batteries Typical Application ■ Notebooks ■ Handhelds ■ Calculators A typical requirement for example is this: ■ Charging current: ■ Discharge current: ■ Bridging time: ■ Operating temperature: 0.1 CA (+0.03 CA) continuous 30–100 mA 1) 5–15 min. 0 to +45°C Wire length (mm) Weight (g) Height without pins (mm) Proper selection of battery capacity is required.
2.6 STANDARD NIMH BUTTON CELL BATTERIES FOR ALARM EQUIPMENT (CAR ALARM, …) Alarm Batteries Typical Application Weight (g) Height (mm) Width (mm) Dimensions (mm), l / b Charge current (mA), 14–16 hours ■ Car alarm equipment ■ Domestic alarm equipment Discharge current (mA), 0.2 CA Nominal capacity (mAh), 5 hours Typical capacity (mAh), 5 hours Nominal voltage (V) Order No. No.
Rechargeable Button Cells 2.7 S TANDARD NIMH BUTTON CELL BATTERIES FOR ELECTRONIC EQUIPMENT The VARTA 9V Block is more than a Battery – it is the world’s most consumer-friendly power pack.
Weight (g) Height (mm) Width (mm) Length max. (mm) Charge duration (h) Standard charge current (mA) Discharge current (mA), 0.2 CA Nominal capacity (mAh), 5 hours Typical capacity (mAh), 5 hours Nominal voltage (V) Order No. No. of cells Type NiMH Batteries for Electronic Equipment V 7/ 8 H R4Use 7 05122 101 501 8.4 180 180 34 17 14 –16 48.5 26.6 15.7 48.0 V 6/8 H 6 05422 106 052 7.2 150 150 28 14 14 –16 48.5 26.6 15.7 41.0 V 7/8 H (EcoPack USA) 7 05522 726 501 8.
Rechargeable Button Cells Comparison of Self Discharge FIG. 5 Discharge characteristics of V 7 / 8 H FIG.
2.8 CHARGING METHODS FOR NIMH BUTTON CELLS ROBUST FAMILY The most suitable method to fully charge sealed rechargeable NiMH Button Cells is the constant current charge for a timed period. Standard Charge Applicable for all NiMH Button Cell series. Charging is with constant current: 14–16 hours at 0.1 CA. Occasional overcharging at the nominal charge current (see page 11) is permissible.
Rechargeable Button Cells Intermittent Trickle Charge NiMH Button Cells can also be charged with this method. As the specified trickle charge is insufficient to fully charge a discharged battery at high temperatures and a constant overcharge at the specified rate or higher limits the life, a modified charging method can be adopted. The following conditions must be observed: ■ Charging of the discharged battery should take place ■ time-controlled with a high rate possible, e.g. 0.
2.9 RECOMMENDED CHARGING CIRCUITS Standard/Accelerated Charge Charge circuit for charging cells/batteries at constant current at normal charge and accelerated charge. The charge process has to be interrupted by a timer at the end of the charging period. UA R1 = I Batt UCE R 78XX UE UA I Batt UE = UCE + UA + UBatt UBatt UBatt max. at UCE = 0 V FIG. 7 Trickle Charge RC IC UE – UBatt max.
Rechargeable Button Cells 2.10 CHARGE TABLE FOR NIMH BUTTON CELLS 0.2 CA 0.5 CA Max. possible Limited fast charge 1) 0.1 CA Trickle charge Accelerated charge Specific currents Normal charge Charge Table 0.01 CA to – 0.03 CA Charge time 14 – 16 hours 7– 8 hours 3 hours unlimited – Recommended 0.1 CA 0.2 CA 0.5 CA 0.01 CA to 0.1 CA for unlimited charging values 14 –16 hours 7– 8 hours 3 hours 0.03 CA period at +20°C. 0.2 CA at room temp.
2.11 DISCHARGE CHARACTERISTICS OF NIMH BUTTON CELLS The capacity and the voltage level of a cell during discharge are limited by various operational parameters. The most important of these are: the rate of discharge, the ambient temperature and the end of discharge voltage. In general, the higher the discharge current, the lower the discharge voltage and the available capacity; this tendency becomes pronounced when the discharge current reaches 2 CA. FIG.
Rechargeable Button Cells 2.12 D ISCHARGE DIAGRAM OF NIMH BUTTON CELLS ROBUST FAMILY FIG.
3.
Rechargeable Button Cells 3.1 C ONSTRUCTION AND ELECTROCHEMICAL PROCESSES OF NIMH HIGH RATE BUTTON CELLS A precision seal, with long diffusion path, ensures excellent sealing properties. The cup of the casing acts as the positive terminal and the lid as the negative terminal. The punched positive sign with precisely predefined rest-wall thickness on the cell serves as a safety device which opens smoothly at predetermined internal pressure, in case of gross abuse.
3.2 FEATURES V…HR(T) POWERFUL (85) ■ Cells with typical capacities from 6 up to 600 mAh ■ Nominal cell voltage 1.2 V ■ Wide operating temperature range ■ Built-in safety device** ■ UL Recognition ■ Fast charge capability (1 CA charge/–∆V)* V 4 5 0 HR time even higher * multi-layer-electrode types ** for cells with 7mm Ø or more V 550 HRA V 600 HRT V 6 00 HR 55815 55945 Type Number 55996 55802 Typical Capacity (mAh) 6.2 18 Nominal Voltage (V) 1.2 Nominal Capacity (mAh) 6 Height (mm) 6.
Rechargeable Button Cells 3.3 N IMH HIGH RATE BUTTON CELL BATTERIES FOR INNOVATIVE IT AND AUTOMOTIVE APPLICATIONS Higher demands for energy and the need for a wide temperature range make this NiMH High Rate Button Cell from VARTA Microbattery an ideal solution for IT and automotive applications. The slim design offers a vast flexibility for product designs. Depending on customer demands, a variety of battery FIG.1 7 VARTA V 600 HRT Made in Germany Example: 4 / V 600 HRT 24.5 mm 13.8 mm 68.
3.4 EXAMPLES OF NIMH HIGH RATE BUTTON CELL V…HR(T) ASSEMBLIES The NiMH High Rate Button Cell generation from VARTA Microbattery is available in a various range of different cell assemblies, e.g.: FIG. 1 8 F IG. 1 9 FIG. 2 0 F IG. 2 1 FIG. 2 2 F IG.
Rechargeable Button Cells 3.5 C HARGING METHODS FOR POWERFUL FAMILY CHARGING METHODS 1. Standard Charge The method to fully charge sealed NiMH cells is to charge at nominal constant current (0.1 CA) with time limited charge termination. The timer should be adjusted to terminate charging after having reached 150–160 % capacity input (15–16 h) to avoid extended overcharge. This charging method may be used in the temperature range of 0 to +65°C.
RECOMMENDED TEMPERATURE RANGE 1. Operating Temperature during Charge Charge efficiency highly depends on operating temperature. Due to the increasing evolution of oxygen at the positive electrode charge efficiency decreases at higher temperatures. At low temperatures charge efficiency is excellent. As the oxygen recombination process is slowed down at low temperature, a certain rise in internal cell pressure may occur depending on charge rate.
Rechargeable Button Cells 3.6 CHARGE TABLE FOR NIMH HIGH RATE BUTTON CELLS V…HR(T) Accelerated charge 1) Fast charge 2) Trickle charge Specific currents Normal charge Charge Table 0.1 CA 0.3 CA 0.5 – 1 CA 0.01 CA to 0.03 CA Charge time 14 –16 hours unlimited Recommended charging charging values at 4 hours 1 – 2 hours 0.1 CA 0.3 CA 0.5 – 1 CA 14 –16 hours 4 hours 0.03 CA unlimited room temperature for the 0.01 CA to powerful family V...
3.7 T YPICAL CHARGING CURVES AT VARIOUS TEMPERATURES AND RATES ROBUST (85) FIG. 2 6 Charging curves at various charging currents of NiMH Button Cells V…H(T) at +23°C A = 0.2 CA B = 0.1 CA C = 0.050 CA D = 0.033 CA E = 0.010 CA FIG. 2 7 Charging curves at various charging currents of NiMH Button Cells V…H(T) at +45°C A = 0.1 CA B = 0.050 CA C = 0.033 CA D = 0.010 CA FIG. 2 8 Charging curves at various charging currents of NiMH Button Cells V…H(T) at 0°C A = 0.1 CA B = 0.050 CA C = 0.033 CA D = 0.
Rechargeable Button Cells POWERFUL (85) FIG. 2 9 Typical charging curves at various charging currents of NiMH High Rate Button Cells V…HR at room temperature A = 1 CA (ML)* B = 0.3 CA (ML)* C = 0.1 CA D = 0.03 CA FIG. 3 0 Charging curves at various charging currents of NiMH High Rate Button Cells V…HR at +45°C A = 1 CA (ML)* B = 0.3 CA (ML)* C = 0.1 CA D = 0.03 CA FIG. 3 1 Charging curves at various charging currents of NiMH High Rate Button Cells V…HR at 0°C A = 1 CA (ML)* B = 0.3 CA (ML)* C = 0.
3.8 D ISCHARGE CHARACTERISTICS OF NIMH HIGH RATE BUTTON CELLS POWERFUL (85) The capacity and the voltage level of a cell during discharge are limited by various operational parameters. The most important of these are: the rate of discharge, the ambient temperature and the end of discharge voltage. In general, the higher the discharge current, the lower the discharge voltage and the available capacity; this tendency becomes pronounced when the discharge current reaches 5 CA. FIG.
Rechargeable Button Cells 3.9 D ISCHARGE DIAGRAMS OF NIMH HIGH RATE BUTTON CELLS V…HR(T) POWERFUL FAMILY FIG.
FIG.
Rechargeable Button Cells 3.10 PERMISSIBLE TEMPERATURE RANGE The NiMH High Rate Button Cells from VARTA Microbattery are suitable for use in a wide temperature range. Operation Temperature During Charge Series HR/HRT Charge efficiency is dependent on operating tempera ture. Due to the increasing evolution of oxygen at the positive electrode, charge efficiency decreases at higher temperatures. At low temperatures charge efficiency is excellent due to higher charge voltage.
4. GENERAL CHARACTERISTICS 4.1 REFERENCES NiMH Button Cells from VARTA Microbattery (Made in Germany) are produced at an outstanding quality level in ISO 9001 certified facilities on fully automated lines. Process control in combination with various internal and external tests, e.g. UL Recognition tests, give our UL Recognition customers the highest reliability and safety for their application. Our NiMH Button Cells are highly environmentally compatible due to an innovative Pb-, Hg- and Cd-free design.
Rechargeable Button Cells 4.2 RELIABILITY AND LIFE EXPECTANCY VARTA Microbattery NiMH Button Cells/Batteries are safe in normal usage and under anticipated conditions of unintentional abuse. Protective devices are incorporated into the cell/batteries to ensure maximum safety.
FIG. 4 2 POWERFUL FAMILY ife expectancy of L V 450 HR, V 18 HRT FIG. 4 3 POWERFUL FAMILY Bridge battery life cycle test of V 18 HRT cell (bridging application) Cycling Method: Charge: 6 mA for 60 min. Discharge: 100 mA to 0.
Rechargeable Button Cells 4.3 PROPER USE AND HANDLING NiMH cells are sealed designs which are maintenance free. These products may be used in any operating position. They should be kept clean and dry during storage and operation. In general, batteries or cells will be shipped in a partially charged state. Therefore caution should be exercised not to short-circuit them at prolonged periods of time. Cells or batteries must be charged before use to obtain full capacity.
Deep Discharge (Over Discharge) Deep discharge or reverse charging will damage the bat tery performance and must be avoided. In order to avoid over discharge of battery which is directly connected to an electronic circuitry, any leakage current must be reduced to minimum or better avoided completely. A switch or a deep discharge cut off device may be connected between battery and associated circuitry to prevent over discharge.
Rechargeable Button Cells CARE AND HANDLING 1. Connections and Terminals Soldering of lead wires directly onto cells can damage the internal components like the gasket and other parts. It is recommended that a tag is spotwelded to the cell, on which lead wires can then be soldered. Never solder onto cells directly! 2. Parallel Cell Configuration Parallel charging may produce unpredictable current distribution into cells. Therefore overcharge and low performing cells may result.
4.4 TRANSPORTATION, SAFETY AND RECYCLING NOTE FOR BATTERIES For latest version please see http://www.varta-microbattery.
Rechargeable Button Cells 4.5 STORAGE/HANDLING Sealed rechargeable NiMH Button Cells from VARTA Microbattery can be operated in any position. Maintenance of the cells is not necessary, they are maintenance-free. However, the cells, like other electri cal components, should be kept clean and dry. The cells complete the manufacturing process in a charged state.
4.6 BATTERY ASSEMBLY Connection and Terminals Never solder onto cells directly! Soldering of lead wires directly onto cells can damage the internal components like the sealing ring and other parts. It is recommended that a tag is spotwelded to the cell, on which lead wires can then be soldered. Parallel Cell Configuration Never connect cells in parallel during charging! Parallel charging may produce unpredictable current distribution into cells. Therefore overcharge and low performing cells may result.
Rechargeable Button Cells 4.7 MULTICELL BATTERIES BATTERY ASSEMBLY RECOMMENDATION 1. Connection between Cells When NiMH cells are connected, spotwelding methods are to be used. This is to avoid excessive temperature rise of the cell which would occur if soldered on to them. Tags used for cell connections should be nickel plated. They should have a 0.1–0.2 mm thickness and be 3–6 mm wide. The temperature of NiMH cells or batteries rises when the charge gets close to completion.
4.8 DEFINITIONS Basically Unless otherwise stated the technical values and definitions are based on room temperature conditions (R.T. = 20°C ±2°C). System – specific data The gravimetric energy density of the NiMH system depends on battery size and ranges from approx. 40–55 Wh/kg and the volumetric energy density ranges from approx.120–180 Wh/l. Voltage Definitions Open Circuit Voltage (O.C.V.): Equilibrium potential 1.25 V to 1.
Rechargeable Button Cells Permanent Charge Current: Recommended current 0.03 CA for capacity retention (also known as trickle charge current). Nominal Discharge Current: The nominal discharge current of a NiMH cell is the 5 hour discharge current (0.2 CA). It is current at which the nominal capacity of a cell is discharged in 5 hours. C C I = = = 0.2 CA when t = 5 h t 5 Ah-Efficiency The ratio of effective available capacity and capacity input is denoted as charge efficiency.
4.9 APPLICATION CHECK LIST CUSTOMER: APPLICATION: Volume cells per year: Samples requested: Target Price: Delivery required: Min. operating voltage VB: (V) Max. VB (V) Operating time required: Hours: Days: Month: DISCHARGE conditions at: Min. temperature: (° C) Max. temperature: (° C) Discharge mode (A) (mA) Operating time Per discharge Continuous discharge Pulse number Pulse discharge Min. Hr. Days Max. current q q q Min.
Product Portfolio PrimaryBatteries Batteries Rechargeable Primary Batteries Li-Ion Button Cells CoinPower CellPac LITE Zinc Air Hearing Aid Batteries – power one Li-Ion Hearing Aid Batteries – power one VARTA pulse (3/6) Lithium Button Cells NiMH Button Cells VARTA element (6/9/12) Lithium Cylindrical Cells NiMH Cylindrical Cells VARTA one L & one XL (2,8 kWh – 13,8 kWh) Alkaline Batteries CellPac PLUS VARTA flex storage E & P Silver Oxide Button Cells Hydrogen Gas Generating Cells CellPac B
