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REQ: PIC16F84 A/V/mAh meter for battery charger?

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Spirit

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mah meter

I built switching inteligent battery charger with MAX712 with discharging unit, and now I want to add digital V meter (15Vdc max), A meter (3A max) and I want to measure battery capacity while is connected to discharging circuit.
Charge-discharge is automatic with LED signalisation so I can get control signal from 3 LEDs (charge, discharge, finish)
I want to do this with PIC16F84 and 16x2 LCD.

Does anybady know how to do this or have some project shematic and hex?
 

phoenixdk

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pic16f battery charger

what are you charging li-ion/polymer ??....
 

Spirit

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battery charger circuit+pic16f

I charge Ni-MH with modified factory switcher schematic and works great. At 2.5A everything is cold.
Before that I tried with linear charger, and disipation was very high.
 

phoenixdk

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pic16f84 ميتر

i dont know to much about that type of battery, but if you want the charger to determin the capacity (Amp-hour), I think I read once that they meaure the internal resistance of the battery, to determine it.

or do you mean how charged the battery is?

bare in mind im not a 100 % sure...

hope it helps a bit
 

Spirit

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pic16f84 charger

I discharge battery with constant curent until 1V per cell.
I need only to measure time of discharging and calculate battery capacity.
If battery discharge take 10 hours at 200mA, than battery capacity is 2000mAh.
Thats all.
Discharging start-stop are automatic.
Discharging current I can select, so I only need timer wich can measure time of lighting "discharge" LED control signal, calculate t*I and display mAh
 

phoenixdk

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pic16f84 nimh

then you should use the timer module in the mcu ,maybe set it to interrrupt every sec , then program a clock counter using arrays u increment (to meausre discarge time) . you could use the signal from discharge led to initiate counter. it shouldent be to difficult to calc. capacity from known lOad and mea sured discharge time.

if i remember correct the pic16f84 has 2 timers you can use.

but if you want to measure mAh wit mcu then you need another pic, since the one you suggested dont have an A/D converter
 

SPATAN

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battery characterizer

This circuit is a battery characterizer that applies a fixed load to a charged NiCad or NiMH cell and measures milliamp-hour capacity as it discharges.

http://www.vermontficks.org/bchard.htm

Good luck...:D
 

surfman

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batery charger pic16f84a

SPATAN said:
This circuit is a battery characterizer that applies a fixed load to a charged NiCad or NiMH cell and measures milliamp-hour capacity as it discharges.

http://www.vermontficks.org/bchard.htm

Good luck...:D

Can you tell me did you test this project? I need compiled HEX file?
 

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