Accessories Temperature Sensors (R) Description Power-One offers a wide range of battery charger systems consisting of adapted power supplies and appropriate temperature sensors. The (lead-acid) batteries are charged according to the battery temperature and the properties of the battery cells. When the battery is fully charged, it is maintained at the float charge voltage, which represents the optimum point for maximum available energy and optimum life expectancy of the battery. It is essential to place the sensor as close to the battery as possible thus sensing the battery temperature. The most suited sensor model is defined mainly by three parameters: The nominal battery voltage (e.g., 24 V or 48 V), the temperature coefficient of the cells (e.g., -3.0 mV/ K), and the nominal floating charge voltage per cell at 20 C (e.g., 2.27 V/cell). The latter two are specified in the data sheet of the battery. The temperature sensors K can be used with all PowerOne converters with the standard R input. This input allows the control of the output voltage, see fig. 1. The open R input exhibits a source voltage of 2.5 V with a source resistor of 4 k. Table of Contents The sensor can directly be connected to the R input and is powered from the battery voltage, as shown in fig. 2. The sensor supersedes the internal voltage control circuit of the converter and adjusts the output voltage exactly to what is needed for the battery. Note: Some converters exhibit a current droop characteristic to ease the operation in parallel connection. If the temperature sensor K is connected to the R-input, it cancels the droop characteristic and impedes current sharing. We recommend the use of converters with true current sharing (option T). Different models of battery sensors are available depending on the battery specifications. Table 1 gives an overview of available sensors. Note: Other types for different cell voltages, temperature coefficients, and cable lengths are available on request. For example, if the application uses a 48 V battery consisting of 24 cells of 2.27 V, a temperature coefficient of - 3.0 mV/K, and 2 m cable length, the sensor type S-KSMH48-2.27-30-2 should be selected. Fig. 3 shows the charge voltage depending on the temperature and the battery type. If the sensor is Page Page Description ..................................................................... 1 Fail Safe Operation ......................................................... 2 Converters with DC Input ............................................... 3 Mechanical Dimensions ................................................ 3 Temperature Sensors for the T Series .......................... 3 BCD20024 Rev. AA, 03-Sep-2008 Page 1 of 3 www.power-one.com Accessories Temperature Sensors (R) Table 1: Sensors for converters with standard R input Sensor002 Vo+ L Vref = 2.5 V 4 k R Control circuit Battery voltage nom. [V] Sensor type 12 S-KSMH12-2.27-30-2 2.27 - 3.0 2 24 S-KSMH24-2.27-30-2 2.27 - 3.0 2 24 S-KSMH24-2.27-35-2 2.27 - 3.5 2 24 S-KSMH24-2.31-35-0 2.31 - 3.5 4.5 24 S-KSMH24-2.35-35-2 2.35 - 3.5 2 48 S-KSMH48-2.27-30-2 2.27 - 3.0 2 48 S-KSMH48-2-27-35-2 2.27 - 3.5 2 Rsafe N Vo- Fig. 1 Block diagram of Power-One converters suited to be controled by a battery sensor. 03099d Input Power supply Vo+ Vo- + Load R R Cell Cell temp. Cable voltage coefficient length [V] [mV/K] [m] - Sensor wires Sensor Temperature sensor cable white brown Vo+ + Vo- Battery Battery + - Temperature sensor Fig. 2 Block diagram of the sensor. Fig. 4 Connection of a sensor to the standard R input disconnected, the converter output voltage is regulated to Vo safe. This voltage prevents the battery from being overcharged even at high temperature. Overcharging a battery is dangerous and can cause the battery to explode. Fail Safe Operation Cell voltage [V] 2.45 06123b 2.40 Vo max 2.35 To prevent batteries from overcharging but still maintain a minimum charging in case of interruption of the sensor signal cable to the power supply, Power-One offers converters with a special nominal output voltage setting; see table 2. These converters differ from the respective standard models in the nominal output voltage and output current settings. Without the sensor connected to the R pin, the output voltage is set to Vo safe, which is higher than the nominal battery voltage such avoiding discharging the battery, but still lower than the theoretically needed float 2.30 Sensor002 Vo+ L 2.25 Vref = 2.5 V 2.20 2.15 Vo safe 2.10 -20 - green 05174a + Fuse 4 k R Control circuit -10 0 10 VC = 2.27 V, -3 mV/K VC = 2.23 V, -3 mV/K 20 30 40 N Vo- VC = 2.27 V, -3.5 mV/K VC = 2.23 V, -3.5 mV/K Fig. 3 Float charge voltage versus temperature for different temperature coefficients. BCD20024 Rev. AA, 03-Sep-2008 50 C Rsafe Fig. 5 Connection of Rsafe, if standard converter models are used. Page 2 of 3 www.power-one.com Accessories Temperature Sensors (R) Table 2: Special models for battery charging Vnom [V] Vsafe [V] Po = 50 W Po = 70 W Po = 100 W Po = 125 W Po = 150 W Po = 250 W 12 12.84 LM1781-7R LOK4140-2RLD LH1781-2R LS4740-7R 2 LWR1140-6EM1 LK4740-7R CK1740 3 LWN1140-6EM1 24 25.68 LM1782-7R LOK4240-2RLD LH1782-2R LS5740-7R2 LWR1240-6EM1 LK5740-7R CK27403 LKP5740-6R LWN1240-6EM1 36 38.52 LM1783-7R LH1783-2R LWR1840-6EM1 48 51.36 LM1784-7R LOK4740-2RLD LH1784-2R LS5740-7R1 2 LWR1740-6EM1 60 64.2 LM1785-7R LH1785-2R 1 2 3 Po = 280 W Po = 375 W Po = 500 W LKP5741-5R LXR1240-6M1 LXN1240-6M1 LWN1840-6EM1 LK5740-7R1 CK27401 3 LXR1840-6EM1 LXN1840-6EM1 LKP5740-6R1 LKP5741-5R1 LXR1740-6M1 LWN1740-6EM1 LXN1740-6M1 Both outputs connected in series. Similar models with DC input (DS/LS1740, DS/LS2740) are available as well. DC input; DK/LK1740, and DK/LK2740 are available as well. charge voltage. As soon as the sensor is connected to the R pin, the output voltage will be set to the correct value. This is essential for best energy and battery life time. For this purpous, DC-DC converters of Q, P, M, S, or K Series may be used, such as all switching regulators, provided that they exhibit the standard R input. Other Power-One converters may also be used for battery charging controled by the temperature sensor. However, the output voltage at low temperature might not be reached. If the sensor is used only for decreasing the output voltage, for instance, if using a 15 V power supply to charge a 12 V battery, then disconecting the sensor results in a dangerous situation. We recommend to add a resistor between the R input and its reference, which adjusts the output voltage with disconnected sensor to Vo safe. This is shown in fig. 5. For safe operation, we recommend to provide a resistor Rsafe with the correct value (see fig. 5). Mechanical Dimensions All dimensions in mm. L Temperature Sensors for the T Series T Series battery chargers exhibit a cell voltage selector switch to set the required floating charge voltage directly at 9.8 (0.4") 26 (1.02") 09125a Converters with DC Input Most of the models listed in table 2 have an AC input. However, there are applications requiring battery charging from a DC source - sometimes even without electrical isolation. European Projection 56 (2.2") L = 2 m (standard length) other cable lengths on request adhesive tape Fig. 6 S-KSMH temperature sensor. the converter. A special temperature sensor T matches to the T Series. All details are provided in the T Series data sheet at Power-One's web site; see www.power-one.com. NUCLEAR AND MEDICAL APPLICATIONS - Power-One products are not designed, intended for use in, or authorized for use as critical components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written consent of the respective divisional president of Power-One, Inc. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending on the date manufactured. Specifications are subject to change without notice. BCD20024 Rev. AA, 03-Sep-2008 Page 3 of 3 www.power-one.com