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Intelligent battery charger circuit

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kit_714

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intelligent battery charger circuit

Dear All,

I would like to build a module of battery charging circuit, better can use microcontroller to monitor the status. Is there any recommendations on those battery charging ICs to acheieve the task?

If yes, kindly leave the information for me.

Thanks.

Kit
 

btbass

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atmel battery charger

You might find a solution at Microchip application notes
 

kender

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pulse battery charger circuit

kit_714 said:
Is there any recommendations on those battery charging ICs to acheieve the task?
Kit,

What cell chemistry are you planning to use? What capacity? Charging is different for Lithium and Nickel chemistries.

Nick
 
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nguyennam

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intelligent battery charger

You should refer to Microchip and Atmel website for PIC and AVR MCUs application notes on charging batteries.

For chemistries and algorithm, as well as excellent ICs dedicated to batteries charging, you should go to Maxim website.
 

hamed_sotoudi

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battery charger circuit

Hi
go to atmel website. and search for battery charger. there is one document about battery charger with atmega8 and atiny15 and u can download its codes in c and assembly for them. but u should change the codes alittle for your battery types. and u can implement it very easily.
 
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inventor(y)

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pic charger

Don't use the atmel app. It's complete nonsense.
It's designer must have bin sleeping. Just look at
the mosfet driver and the way the program is written.
if you want to use it, make an extra board with a fire extinguisher
trigger circuit. a 10 K PTC and some comparators work fine here.
 
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ChineseDragon

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sla battery charger circuit

Go to TI and Maxim website.
 
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contagiouseddie

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intelligent battery charger schematic

Hi There,

I just came back from a Microchip battery charging seminar and lab session.
I have been using TI's BQ series for quite some time and I guess they are better than Microchip's one in term of minimal external components, charging current capability, and wide input range.
 

inventor(y)

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battery charger circuits

Hi contagiouseddie , what BQ have you used? I tried the BQ2004. But it never worked like it should. Later I came across a battery charger using the same chip having the same problem as my design. I'm now using my own design based on an ATMEGA48. Low part count/low cost. (ATMEGA €0.8 )
 

hamed_sotoudi

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atmega8 battery charger

inventor(y) said:
Don't use the atmel app. It's complete nonsense.
It's designer must have bin sleeping. Just look at
the mosfet driver and the way the program is written.
if you want to use it, make an extra board with a fire extinguisher
trigger circuit. a 10 K PTC and some comparators work fine here.
I dont know why u say like that. I use it but I made some changes to it and it has been working very well till now.
 

inventor(y)

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battery charger atmega

Hi,

-NiMh version uses -Delta V technique. This is not suitable for NiMh unless you charge with very high currents. Something the hardware can not do.
-Take a close look at the 0R25 sense resistor in the switching current source and try to find out what PWM resolution you need to get it to work stable.
-The software doesn't use a watchdog while using while loops for polled IO. It should at least use a watchdog timer for Li-Ion batteries.
-The stable ADC function.
-...


Regards
 

PaulHolland

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nimh charger pic16f

Design one yourself like I did with discrete components. I designed a SLA battery charger with an 10uA idle current and temperature compensated also. Current and Voltage limited and C-I and C-V charging.
 

RenatoBR

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12vdc battery charger circuit

quote="Dexter Dude

It's a good charger. I have built it with an PIC16F628A ( changed the asm code for this PIC but the logic of the charger is the same ).

Good luck.[/quote]


Hi all,

Congratulations Dexter, a long time looking for a charger with pic 16F628A, but I didn't find it on the web.
I don't have konwledge enough in pics to write or change a source code.
Pls, can you post Your schematic and the source code?

Rgds,


Renato
 

Dexter Dude

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bat charger atmega8

This is the schematic for the charger (PIC16F628A / osc int 4MHZ).If needed , one could add at pin RB7 a simple serial intreface to PC.This way you could watch the voltage of Acc. , time , and state of charger using a program like RealTem or Hyperterm .



The charger perform a self test (if batt not inserted) , then checks the number of acc. connected (1-4) and display this number for 2 seconds .Then starts the discharging process till 1V/element .When discharging has finished , it pauses for 35sec(cool down) then enter into Slow charge mode (display indicates S ) for 450sec . After that it triggers High charge mode (display indicates H ) . The algoritm of charging is somehow similar with Eric's Brouwer
http://myweb.absa.co.za/eric.brouwer/electronics.htm .
This charger performs a so called "reflex charging" or "Burp charging" , and it is the most advanced charger I had buid (so far) .I must say , I am very pleased of it.
It is simple , cheap ,robust and works quite well , even with old accumulators .It is suitable for NiCd and Nimh batteries.
This is the latest hex file for PIC16F628A :
http://depositfiles.com/files/2651036 <- tested OK

For burning must use this settings :
IntOsc/ IO WDT=off PWRT=off MCLR=OFF BODEN=ON CPD=Off CP=off




The 7 segment digit display works like this:
- 0 for discharging
- I for battery In
- S for Slow Charging
- H for High (Normal) charging
- P for Fail to detect Peak
- F for Finish charging , or Trickle reflex charging
- E -for Error
- E A - for Error on Acc (battery removed while charging)

This is the schematic used for the 7segment display( I had 2 digits glued together so I made a separate PCB for this 2 digit display but only one connected to PIC )


The the switch (Ra5 to GND) could be omitted .It's function is not implemented yet.

The diode is a cheap 3A (not a Schotky diode becouse you need at least 0.6V on it .)When Lm317 is turned off it still outputs 1.25V-1.3V .So :
1.25V-0.65V= 0.6V on out when Lm317 is turned off.In practice I obtained 0.75V (the Delta Sigma ADC has some influence ).
This voltage is used to detect if at least one element is attached .After you build the circuit , with PIC removed , you must check this voltage to be soure that everything working fine.The software need at least 0.92V to detect one element , so this voltage must be in range of 0.6V-0.92V .
 

wizpic

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battery charger with atmega

Dexter Dude what did you write the software in ?

Want to share source code ?

wizpic
 

RenatoBR

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schematic diagram to inteligent battery charge

Thank you Dude,

Interesting circuit, wich type of diode can be used for "D"?
If possible share the source code, pls.


Rgds

Renato
 

linhnc308

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intelligent battery charger circuit schematic

My opinion, diode D is 1N4007 or Shotsky diode, maximum current is about 2 or 3A
 

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