60AH Lead Acid Battery charging with micocontroller

[u04f061]

Dear kautilya1987

What is your maximum current at absorption stage and bulk stage? Which topology you are using i.e flyback, forward etc.? What is the capacity of your battery? I am experienced at dspic and can help you in configuring your MCU and implementation of control loop. Please expedite your queries one by one. I will post results. Which particular controller and compiler you are using?

 

[tarikul]

Sir, what is face control battery charger? Bimtex IPS India is apply this formula. Sir, i have no link for Bimtex diagram. Just i bought that cercuit from market and use. So i want to make same cercuit. i make drivar and power section but can not draw their chargeing site. So you are my last direction. Bimtex apply face contro system for charge led acid battery and it is very nice because i use this cercuit. I think they use scr tyn612m + 4n35 etc. please make any diagram like this for me. thank you. my email id is (jollyrm@gmail.com). please send me cercuit diagram.

 

[Tahmid]

Take a look here: https://www.edaboard.com/threads/181497/#post759620

For detailed information, Google "Phase Angle Control".

After reading up on it, if you have any questions, you may ask here.

 

[tarikul]

Dear Tahmid vai, please make simple Phase Angle Control diagram for me. i want to charge conostantly 200amp Hamko battery by this cercuit. I can not find any Phase Angle Control diagram by google. so you are my last. I want to conect transformar 140v tape and control output amp to charge my battery. Tahmid vai please give me your facebook id or email id please. i want to chating with you. i am waiting for your answer. thank you.

 

[tarikul]

Dear Tahmid vai, please make simple Phase Angle Control diagram for me. i want to charge conostantly 200amp Hamko battery by this cercuit. I can not find any Phase Angle Control diagram by google. so you are my last. I want to conect transformar 140v tape and control output amp to charge my battery. Tahmid vai please give me your facebook id or email id please. i want to chating with you. i am waiting for your answer. thank you.

 

[tarikul]

Tahmid vai can i use this cercuit diagram for my transformar 140volt tape input and control output ampior? please cheik this web and result me. https://www.circuitstoday.com/scr-control-circuits

 

[Tahmid]

Tahmid vai can i use this cercuit diagram for my transformar 140volt tape input and control output ampior?

No.

Along with changing the firing angle manually, you need to be able to adjust the firing angle depending on the output current.

 

[tarikul]

Tahmid vai please give me a diagram link that suiteble for my project. I am waiting for your link. i want to control output by controling ac input. I use this cercuit diagram for my transformar 140volt tape input and control output ampior.

 

[tarikul]

Tahmid vai please give me a diagram link that suiteble for my project. I am waiting for your link. i want to control output by controling ac input. I use this cercuit diagram for my transformar 140volt tape input and control output ampior.

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Tahmid vai please give me a diagram link that suiteble for my project. I am waiting for your link. i want to control output by controling ac input. I use this cercuit diagram for my transformar 140volt tape input and control output ampior.

 

[Tahmid]

It's not that simple. Usually the control is done by microcontrollers. In some cases when microcontrollers aren't used, they are done by operational amplifiers. I don't have any ready made circuit that I can give you. But you should go through this: **broken link removed**

 

[--BawA--]

Hi,
In such a case, I think it should be like this:
1) Sense battery voltage with ADC and check if it is > 14.3v or not.
2) If not, measure the voltage across the shunt and adjust PWM to that point where voltage across shunt corresponds to ~7A.
3) Continue checking battery voltage.
4) If 14.4V reached, adjust PWM to gain 14.4v charging voltage.
5) Sense Voltage drop across shunt to check amount flowing through to battery.
6) If current < 2A, adjust PWM to gain 13.6v charging voltage.
7) If not continue checking voltage.


Tahmid

Is it necessary to measure the battery voltage and current flow during the off cycle of PWM? if we continuosly measure the voltage and current and change the duty cycle accordingly,will it be a right procedure ?

 

[Tahmid]

The thing to keep in mind is that while charging (and also for a short while after charging is stopped), the voltage you measure across the battery is higher than the actual battery voltage (how much higher depends on your charging voltage and current). You might want to check the battery voltage a short while after stopping charging; you might also just do it periodically when you stop charging, wait for a while, and then check the battery voltage.

The current flow - you can measure at any time since you'll be getting the value of the current flowing through at that time. Keep in mind the difference between any instantaneous current you measure and the average current over a period of time.

Hope this helps.
Tahmid.

 

[--BawA--]

thanks tahmid
you had said that(post #31) sense the battery voltage , and then adjust the pwm such that the current flowing through the battery is 7amps. and in 3rd step u had written that continue checking battery voltage.
so i think the code should be something like that
while(1)
{
if ( Vbatt < 14.3 )
{
while(current < 7)
{
dutycycle++;
}
}
i if (Vbatt > 14.2)
{
dutycycle--;
}
if(Vbatt = =14.2)
{
dutycycle_new=dutycycle;
}
}
this code is not complete. it is just a part of main code. The code does not include float charging and cutoff.
i am generating the pwm using timer interrupt and dutycycle is updated after every time period.
but in post#32 u have said that check the battery voltage a short while after stopping charging, so if i do not check the battery voltage continuosly ,there might be the posibility that to keep the current to 7 ampere ,the applied terminal voltage to the battery become greater than 14.3, which is certainly in desirable.
1) so is the above sample code is correct?
2) when should i measure the battery voltage during charging process, should i not monitor the voltage continuosly?

In some microchip application note it was written that " terminal voltage and current are measured during the off cycle of PWM. what was the reason behind that.

 

[Adano]

Hi,

In India and Bangladesh, most inverters (linear types) make use of phase angle control for battery charging. Some use microcontrollers to achieve this, while others use operational amplifiers. If you know how to use microcontrollers, then it is not very tough.

The line voltage (220VAC) is cut (phase angle control) and supplied to a 140V transformer tapping. By how much it is cut or at which angle the triac or SCR is fired is varied by a pot, which in turn controls the charging current. At the output, the MOSFETs which operate in push-pull mode in the inverter, now act as rectifiers (internal body diodes used) and the output supplied to the battery.
The line voltage is sensed and the output voltage after phase angle control is kept constant by altering the phase angle and so, constant current charging is implemented.

Battery voltage is sensed and when it reaches approximately 13.5v, charging is terminated or charging current is reduced, depending on the designer's wish.

I have developed a code with ATMEGA16 for a single microcontroller inverter, where the ATMEGA16 controls the entire inverter, including charging. Here I have successfully charged 100AH battery at 14A, with ability to charge at currents in the range of 5A to 25A adjusted by a variable resistor.

Hope this helps.
Tahmid.
Tahmid.

Hi Tahmid...

I am embarking on a design of swpm dc-ac inverter with push pull configuration using Atmega8. I am using low frequency transformer. I have been able to generate the sine wave and was able to achieve decent pure sine wave at output after filtering. My problem however is the charging circuitry for the battery. I want to use the same transformer for charging the battery when mains is available, but i don't really get how to go about it.

From reading some post on the forum, I understand that i need to have a phase angle control at the secondary winding through a winding tap of say 140v. Also, during the charging phase, the switches(mosfet or igbt) must be kept off. My main problem is how to achieve the constant voltage and current during charging for SLA batteries using this scheme.

Chopping the input ac will regulated the voltage at the primary winding during charging, but how do i control current drawn?

Please, an explanation of to go about this will be highly appreciated. thanks in advance:smile: