Intelligent battery charger circuit

lm317 pulse charge

hi dexter dude, can u tell me the component of battery charger function of the smart battery charger u attach in this forum and how the circuit operate? Thanks...

bq2004 charger scheme

"was wondering if you could please modify the code of the PIC to deliver a RS232 data stream during any operation mode"

This function was already implemented . It looks like this :

atmega battery charge

Hi all

Finally i build "my" smart charger... easy to mount, easy to calibrate.

Tested and works great with 2 and 3 cells... not tested with 1 e 4 cells yet, but i think have no problems with this.

Edit: With 2 cells, the cells are discharged to 1.1v each and then charge, this are correct? the cells don't need be discharged to 0.95 or 1v each?

Without batt in, realterm display 735mv and read=725, my DV Minipa display 750mv, it's ok?

Thanks Dude, Thanks one more time!!

Sorry for my bad english

Thanks!

12 dc power battery charger circuit

can anyone post me the explaination for IBC circuit ? I don't understand the usage for the component? Is the LM317 a volatge or current regulator?

lithium ion battery charger with pic16f628

Lm317 is used as constant current regulator.

See here www.angelfire.com/electronic/hayles/charge1

intelligent nicd charger circuit

Hey can anyone explain how this circuit operation and how the component function for me?

reflex charging circuit

May i know how to set the pwm for the PIC to the LM317?

delta v charger schema

Really a great circuit....can anyone try to explain it...i also interested to know more about it.........

circuits for reflex charging

hey, dexter, may u tell the component function in ur circuit? y u din use crystal to stabilize the 4Mhz of ur PIC16F628A?

circuit smart charger battery nimh atmega8

https://www.angelfire.com/electronic/hayles/charge1.html

I used PIC16F628A ( no XTAL needed ). LM317 forms a constant current supply switched on and off by a micro-controller . A 5V rail for the PIC is developed through a LM7805 3-pin regulator. T he LM317 will maintain 1.25V between the OUT pin and the ADJ pin. I used a large 5W resistor here to ensure a constant 1.5A supplied. You can select this value as suits your batteries ( charge current should be no less than C/2 where C=battery capacity [mA] ) . Just use Ohms law and divide the 1.25Volts by the current that is recommended for full charge. For example 0.68 ohms will provide about 1.7A ( 1.5A actually because LM317 is limited internally to 1.5A ) and 1.2 ohms will provide about 1A.
"The IN5404 diode ensures that the circuit charges the battery, and prevents the battery running the circuit, should the input power be accidentally turned off! If this does occur with a fully charged pack, the diode isolates the circuit and upon turn on the charger will find the battery peak again and return to a trickle charge after just a few minutes."
"When the transistor is biased on, it effectively takes the ADJ pin to about 0.2V. This means the output voltage of the whole unit is about 0.5V. The transistor is biased on by default, to ensure that the unit is "fail-safe". The PIC can turn the transistor off by shorting the base to ground, and this allows the LM317 to provide a regulated, constant current output. The drive current for the PIC, the transistor base and the transistor collector are all in the order of 1mA which is within the rated range of the PIC and transistor."
"A final feature of the software is that there is a Built-In-Test (BIT) upon power up that effectively tests all of the components except the capacitors (more than 80% of the components). During power up, if no battery is detected the output is turned on for 1 second and the voltage checked, and then the output is turned off. "

The bridge rectifier and capacitor should produce about 1.4 times the AC RMS input. So if using a 10VAC supply, the main rail should be about 14VDC. . At least 2.5V is dropped through the LM317, current sensing resistor and output diode. Also check that the 5V rail is regulating properly. LM317 will need to be mounted on a heat sink .

"If you power up the charger with no batt in it will display E A . "
" - If the switch is closed ( RA5 is low ) then the charger will skip the discharging faze.
- If the switch is open (RA5 is high ) the charger will perform as usual ( discharge and then charge ) "


Thank you Wicked Witch for your observations .
a: "The remedy is (like with most linear regulators that exhibit oscillations) a 47-100nF ceramic cap from the output (i.e. pin 2 of LM317) to ground. "
b: "Second I assume that the 4K7 resistor from G to S of IRF530 is counterproductive when ...."

intelligent battery charger schematics

Thanks...

atmel battery chartger

Hi Dexter.
In this period, I built your battery charger and it works as expected! Now I can discharge and charge from 1 element to 4 batteries without any problem.

I have only a little problem with the RS232: using a scope, I can see that the PIC send data every second, but on PC I can see data only every 3 seconds more or less (it is not constant: sometimes I can see every second, rarely every two seconds and more often every 3 seconds).
Is it normal? If not., have you got an idea what's wrong with my circuit? Can it be a problem with the calibration of the internal oscillator?

Thanks again for sharing your circuit

Regards.
Luca.

atiny15

Your circuit is fine.

Data is send thru RS232 every second only when measured voltage has changed or every 3 seconds if data stays the same. This way is easier to plot data by omitting unnecessary points.

intelligent 12v battery charger circuit

**broken link removed**

charger atmel circuit

Hi ! I want to build this charger, but, unhappiness, I do not found 1.25 ohm resistor or 0.8 ohm. Can I replacing them with 1.2 ohm (@ 5W) respective with 0.78 ohm (parallel of 1 ohm and 0.56 ohm, @ 5 W each) ? Can I use diode BY550-800 instead 1N5904 ? Thanks in advance for Your support ...

delta v battery charger circuit

Hello fratello

I think you can use that resistors values, no problem.
I'm using 1R5 and 0R94 and the charger works fine.

About the diode: Is necessary a drop voltage of 0.7v under diode to circuit works. Verify voltage under diode with a digital multimeter, 0.6~0.7v i think are OK.

Ps: Parallel 1 ohm and 0.56 ohm result 0.36 ohm, just recalc.

Regards.

atmega32 battery charger

Thank you !
One more question : in the pcb file is one R=0,75 ohmi, instead 1,25 ohmi in schematic. Why ?
...b.t.w. You are wright, my mistake : 1/R eq = 1/R1 + 1/R2...stupid me...
All the best !

battery charger schematic pic

Hello!

the 0.75 ohm in pcb i think is for use the maximum current (1.5A).. 1.25 ohm is for 1A.

I use 1.5 ohm resistor and get 0.86A, it's good for me.

Sorry for my bad english

Regards.

pic battery charger schematic

Thank You for a such fast reply ! Sorry for my english too... About the schematic : I hope I understand the reason for changing this resistor...Now can I begin to build this great project ! All the best !

schematic battery charger

Good luck!

Regards.