V Charger Circuit Diagram

The charger is based on a charging voltage of 2.4 V per cell, in accordance with most manufacturers recommendations. The circuit pulses the battery under charge with 14.4 V (6 cells ? 2.4 V per cell) at a rate of 120 Hz. The design provides current limiting to protect the chargers internal components while limiting the charging rate to prevent damaging severely discharged lead-acid batteries. 

The maximum recommended charging current is normally about one-fourth the ampere-hour rating of the battery. For example, the maximum charging current for an average 44 ampere-hour battery is 11 A. If the impedance of the load requires a charging current greater than the 11 A current limit, the circuit will go into current limiting. The amplitude of the charging pulses is controlled to maintain a maximum peak charging current of 11 A (8 A average).

V Charger Circuit Diagram

V Charger Circuit Diagram

Read More..

Battery Charger Solar Panel Atmel ATtiny13V

Battery Charger Solar Panel Atmel ATtiny13V

Batwatch is a simple monitor for a solar panel battery charger, using an Atmel ATtiny13V. It periodically measures the allegation accepted and array voltage, and shows them by blinking two LEDs. I congenital this ambit into the bung of a VW solar charger console that is acclimated to anticipate a acquittal of the array back a car is not acclimated for some time. A avant-garde car contains a ample bulk of electronics, and a quiescent accepted of 40-50mA (about 1Ah per day!) is advised "normal"

Every brace of seconds, the software samples the two analog inputs, calculates the allegation accepted and array voltage, and shows the voltage on the red LED and the allegation accepted on the blooming LED. The voltage is apparent in units of 0.1V appliance three decimal digits, and the accepted is apparent in units of 10mA appliance two decimal digits. Anniversary chiffre is represented by a cardinal of abbreviate flashes agnate to the amount of the digit. A aught is represented by a distinct best flash. When the allegation accepted is beneath 10mA (after rounding) or negative, the blooming LED is not angry on at all.

I use 4 times oversampling to get an 11-bit result, afterward the address declared in the Atmel appliance agenda AVR121. Im not abiding if there is abundant babble on the inputs to absolutely access the resolution, but it will not aching either. The raw A/D account is adapted to a voltage appliance a abstracted brace of offset/gain constants for anniversary input. These constants are acquired from the arrangement abstracts stored in the EEPROM.

To save power, all delays are implemented by active one or added beddy-bye instructions which account the CPU to abandoned until the abutting timer interrupt. The arrest abundance is 100 Hz, so anniversary beddy-bye pauses up to 10 mS.

Read More..

Low Cost Universal Battery Charger

Low cost solution for charging of both NiCd and NiMh batteries

Here is the circuit diagram of a low cost universal charger for NiCD - NiMH batteries. This circuit is Ideal for car use. It has ability to transform a mains adapter in to a charger . This one can be used to charge cellular phone, toys, portables, video batteries, MP3 players, ... and has selectable charge current. An LED is located in circuit to indicate charging. Can be built on a general purpose PCB or a veroboard. I hope you really like it.

Picture of the circuit: 

 A Low Cost Universal Charger Circuit Schematic

Circuit diagram:

A Low Cost Universal Charger Circuit Diagram

Parts:

R1 = 120R-0...5W
R2 = See Diagram
C1 = 220uF-35V
D1 = 1N4007
D2 = 3mm. LED
Q1 = BD135
J1 = DC Input Socket

Specifications:

• Ideal for in car use.
• LED charge indication.
• Selectable charge current.
• Charges Ni Cd or NiMH batteries.
• Transforms a mains adapter into a charger.
• Charge cellular phone, toys, portables, video batteries …

Features:

• LED function indication.
• Power supply polarity protected.
• Supply current: same as charge current.
• Supply voltage: from 6.5VDC to 21VDC (depending on used battery)
• Charge current (±20%): 50mA, 100mA, 200mA, 300mA, 400mA. (selectable)

Determining the supply voltage:

This table indicates the minimum and maximum voltages to supply the charger. See supply voltage selection chart below.

Example:

To charge a 6V battery a minimum supply voltage of 12V is needed, the maximum voltage is then 15V.

Voltage selection:

Voltage Selection Chart For Low Cost Universal Battery Charger

Determining the charge current:

Before building the circuit, you must determinate how much current will be used to charge the battery or battery pack. It is advisable to charge the battery with a current that is 10 times smaller then the battery capacity, and to charge it for about 15 hours. If you double the charge current , then you can charge the battery in half the time. Charge current selection chart is located in diagram.

Example:

A battery pack of 6V / 1000mAh can be charged with 100mA during 15 hours. If you want to charge faster, then a charge current of 200mA can be used for about 7 hours.

Caution:

The higher charge current, the more critical the charge time must be checked. When faster charging is used, it is advisable to discharge the battery completely before charging. Using a charge current of 1/10 of the capacity will expand the lifetime of the battery. The charge time can easily be doubled without damaging the battery.

Note:

• Mount the transistor together with the heatsink on the PCB, bend the leads as necessary. Take care that the metal back of the transistor touches the heatsink. Check that the leads of the transistor do not touch the heatsink.

Source : http://www.ecircuitslab.com/2011/08/low-cost-universal-battery-charger.html

Read More..