Accessories Temperature Sensors sensor supersedes the internal voltage control circuit of the Description converter and adjusts the output voltage exactly to what is Melcher offers a wide range of battery charger systems needed for the battery. consisting of adapted power supplies and appropriate Note: Some converters exhibit a current droop characteristic to temperature sensors. The (lead-acid) batteries are charged ease the operation in parallel connection. If the temperature sensor according to the battery temperature and the properties of the K is connected to the R-input, it cancels the droop characteristic battery cells. When the battery is fully charged, it is maintained and impedes current sharing. We recommend the use of at the float charge voltage, which represents the optimum point converters with true current sharing (option T). for maximum available energy and optimum life expectancy of Different models of battery sensors are available depending on the battery. It is essential to place the sensor as close to the the battery specifications. Table 1 gives an overview of battery as possible thus sensing the battery temperature. available sensors. The most suited sensor model is defined mainly by three Note: Other types for different cell voltages, temperature co- parameters: The nominal battery voltage (e.g. 24 V or 48 V), efficients, and cable lengths are available on request. the temperature coefficient of the cells (e.g. 3.0 mV/K), and For example, if the application uses a 48 V battery consisting of the nominal floating charge voltage per cell at 20 C (e.g. 2.27 24 cells of 2.27 V, a temperature coefficient of 3.0 mV/K and V/cell). The latter two are specified in the data sheet of the 2 m cable length, the sensor type is S-KSMH48-2.27-30-2. battery. Fig. 3 shows the charge voltage depending on the temperature The temperature sensors K can be used with all Melcher and the battery type. If the sensor is disconnected, the converters with the standard R-input. This input allows for the converter output voltage is regulated to V . This voltage o safe control of the output voltage, see fig. 1. The open R input ex- prevents the battery from being overcharged even at high hibits a source voltage of 2.5 V with a source resistor of 4 k . temperature. Overcharging a battery is dangerous and can The sensor can directly be connected to the R-input and is cause the battery to explode. powered from the battery voltage, as shown in fig. 2. The Table of Contents Page Page Description ............................................................................ 1 Mechanical Dimensions ........................................................ 3 Fail Safe Operation and Suitable Converters ....................... 2 Temperature Sensors for the T Series .................................. 3 Converters with DC Input ...................................................... 3 Copyright 2016, Bel Power Solutions Inc. All rights reserved. MELCHER BCD20004 Rev AC, 12-Apr-2016 The Power Partners. Page 1 of 205174a Accessories Temperature Sensors Table 1: Sensors for converters with standard R input JM114 L Vo+ Battery Sensor Cell Cell temp. Cable voltage type voltage coefficient length nom. V V mV/K m V = 2.5 V 4 k ref R 12 S-KSMH12-2.27-30-2 2.27 3.0 2 + 12 S-KSMH12-2.27-35-2 2.27 3.5 2 Control logic 24 S-KSMH24-2.27-30-2 2.27 3.0 2 24 S-KSMH24-2.27-35-2 2.27 3.5 2 N Vo- 24 S-KSMH24-2.31-35-0 2.31 3.5 4.5 24 S-KSMH24-2.31-35-2 2.31 3.5 2 Fig. 1 Block diagram of Power-One converters suited to be 24 S-KSMH24-2.35-35-2 2.35 3.5 2 controled by a battery sensor. 48 S-KSMH48-2.27-30-2 2.27 3.0 2 48 S-KSMH48-2-27-35-2 2.27 3.5 2 03099d Vo+ Power + Vo Load Sensor Sensor Temperature Input supply wires cable sensor R white R brown Vo+ Fuse + + green Vo Battery Temperature sensor Battery Fig. 4 Fig. 2 Connection of a sensor to the standard R input Block diagram of the sensor. output voltage setting see table 2. These converters differ from the respective standard models in the nominal output voltage Fail Safe Operation and Suitable Converters and output current setting. Without the sensor connected to the R-pin, the output voltage is set to V . This voltage is o safe To prevent batteries from overcharging but still maintain a higher than the nominal battery voltage such avoiding minimum charge in case of interruption of the cable from the discharging the battery, but still lower than the theoretically sensor to the converter, we offer models with special nominal needed float charge voltage. As soon as the sensor is connected to the R-pin, the output voltage will be set to the Cell voltage V correct value. This is essential for best energy and battery life 06123c 2.45 time. 2.40 The standard converters may also be used for battery charging V o max controled by the temperature sensor. However, the correct 2.35 output voltage at low temperature might not be reached. If the sensor is used only for decreasing the output voltage, for 2.30 instance, if using a 15 V power supply to charge a 12 V battery, 2.25 Sensor002a 2.20 L Vo+ V o safe 2.15 V = 2.5 V 4 k R ref 2.10 + 20 10 0 10 20 30 40 50 C Control R safe V = 2.27 V, 3 mV/K V = 2.27 V, 3.5 mV/K logic C C V = 2.31 V, 3 mV/K V = 2.31 V, 3.5 mV/K C C N Vo- Fig. 3 Fig. 5 Float charge voltage versus temperature for different temperature coefficients. Connection of R , if standard converter models are used. safe MELCHER BCD20004 Rev AC, 12-Apr-2016 The Power Partners. Page 2 of 2 +