Battery Chargers » car battery http://ebatterychargers.com Tue, 27 Jul 2010 11:48:32 +0000 en hourly 1 http://wordpress.org/?v=3.1 Lead acid car battery charger http://ebatterychargers.com/lead-acid-car-battery-charger-20.html http://ebatterychargers.com/lead-acid-car-battery-charger-20.html#comments Sun, 01 Feb 2009 16:46:42 +0000 eBatteryChargers.com http://ebatterychargers.com/?p=20 This circuit delivers an initial voltage of 2.5V per cell to rapidly charge a car battery. The charging current decreases as the battery charges and when the current drops to 180 mA the charging circuit reduces the output voltage to 2.35 V per cell, leaving the battery in a fully charged state. This lower voltage prevents the battery from overcharching, which will shorten its life.
The LM301A compares the voltage drop across R1 with a 18 mV reference set by R2. The comparator’s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-charging current, passing through R1, drops bellow 180 mA.

Temperature compensation helps prevent overcharging, the LM334 temperature sensor should be placed near or on the battery. Because batteries need more compensation at lower temperatures, change R5 to 30Ω for a tc of -5mV/0C per cell il this circuit will be used at temperatures below – 200C.
The charger’s input voltage must be filtered dc that is at least 3V higher than the maximum required output voltage. Choose a regulator for the maximum current needed: LM371 for 2A, LM350 for 4A, LM338 for 8A. At 250C and with no load, adjust R7 for a Vout of 7.05V, and adjust R8 for a Vout of 14.1V.


Car battery charger circuit diagram

lead acid battery charger

]]> http://ebatterychargers.com/lead-acid-car-battery-charger-20.html/feed/ 4 Car battery charger http://ebatterychargers.com/car-battery-charger-15.html http://ebatterychargers.com/car-battery-charger-15.html#comments Sat, 31 Jan 2009 23:36:17 +0000 eBatteryChargers.com http://ebatterychargers.com/?p=15 Car battery charger circuit review:
Modern acid batteries and plates Pb, are embodiment of simplicity in use. Unlike NiCd batteries, they must be recharged by connecting to a constant voltage. In this situation, the loading current will provide a good indication of the state of loading.


Car battery charger circuit diagram

car battery charger diagram

These batteries can be quickly loaded as long as the loading current is limited even at the beginning of the trial proceedings. The charger which we propose it has a voltage regulator, IC1, and a variable current limiter which consists of T1, R1 and R4. Once the current through R1 becomes too large, T1 is opening and the output voltage decreases. Values, in volts, of output voltage is given by the formula: 1.2 (P1 + R2 + R3) / R3
For a 6V battery, the required load voltage for a rapid loading will be 3 x 2.45 = 7.35V. In this case, the actual total value for R2 + P1 will have to be 585 Ω.
To charge 12V batteries, the amount needed for R2 + P1 should be around 1290 Ω. Voltage at the entrance must be at least 3V larger than that of output.
LM317 integrated circuit needs heatsink, not only for that, otherwise, can easily destroy, but also because, at high temperatures, it can not provide the current maximum output.



12v battery charger PCB

car battery charger pcb

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