solar charger technique and tutorial

[aqildad]

i want to design a solar battery charger , can any one guide me which technique is used??? any tutorial ??? please post your experience in this thread .

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this is basic solar charge control circuit in which voltage is control by lm317 and low battery by comparator . . . any further up gradation is necessary ???

 

[KlausST]

Hi,

Some technical informations needed
- What battery chemistry
- what battery voltage
- what battery capacity
- what solar cell max power

You say you want to design.... is this your design? Or do you want to build it this way? If not: why do you want to change something?
What are your goals?

Klaus

 

[aqildad]

Hi,

Some technical informations needed
- What battery chemistry
- what battery voltage
- what battery capacity
- what solar cell max power

You say you want to design.... is this your design? Or do you want to build it this way? If not: why do you want to change something?
What are your goals?

Klaus

Thank you for the detail post .

- i want to built charger for LEAD ACID BATTERIES .
-BATTERY VOLT 12V 165AH
-PLZ GUIDE ME ABOUT SOLAR CELL SELECTION

This is not my design but i thing it the most simplest so i want to built in this way .my goal is to design a best charge controller that's why want to further modify it.

But i dont know what are the necessary features of solar charge controller

 

[KlausST]

Hi,

Lead acid charger... you may find a lot of information about thatcusing google. For example a common used charging method is cccu/ cccv meaning constant current, constant voltage...

165 Ah, and LM317...
how much current is the LM317 able to deliver? Maybe 1A. So it needs 165Ah / 1A = 165 h of charging time. With no extra load, from fully discharged to fuly charged....

Solar cell selection... If the charger can handle 1A max then the solar cell must be able to prvide this 1A. So you need at least 1A at 18V (from your picture) = 18W of cell output power. If you wantvthe 1A at 50% of sunlight brightness, so you need to double you cell output power = 36W. But you can not use more than 1A. The overpower is wasted somehow...

The voltage drop from cell output to battery voltage is wasted also, with this linear charging method. A heatsink will be necessary..

Hope this helps
Klaus

 

[aqildad]

A read some were that a battery should charge max 10% of max rating so in my case 165Ah /10 =16.5 amp . so i am looking for charger upto 16 Amp . so then which technique or process should i follow . which ic will best to control 16 Amp ?

also guide me how we calculate the wattage of solar panel . As per my knowledge for 16Amp: i need 12x16=192Wattage solar panel panel ? i am correct ??

and if i want max rating(16amp) at 50% then total wattage will be 192x2=384wattage ???? what you say ???

i also want to make it as cheap as possible so it will expensive i guess ??

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sir what you say about above circuit ???? it is using lt3755 which is constant current and constant volt regulator

 

[KlausST]

Hi,

You are on the right way.
16.5 A is good. Lets say 10A to 20A is a goid range...
16A with linear regulation looses much power and therefore produces much heat..
I prefer a switching technique, but it is more difficult (layout with switching signals, more to calculate, more to decide..) and it is more expensive.
But you can produce effectivity of 90% and higher, no heatsink...

You calculated 12V x 16A .... these are nominal values for the battery.
The 16A are ok, but you have to calculate with 13.8V for a healthy full charge of a lead acid battery..
Plus the voltage loss in the charger...

So 18V (@ 16A) is a good value. Means about 290W of solar cell power.

Mind not to overload the battery (continously 13.8V, for a short time 14.4V).
And not to under discharge it. Calculate with about 10.5V ...

Hope this helps
Klaus

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Hi,

The circuit seems good..

Look for buck lead acid chargers with a rating of 16A.
Www.linear.com is a good place, other manufacturers are also good.

Klaus

 

[aqildad]

i need help from some one regarding switching solar charge technique and its calculation etc

 

[KlausST]

i need help from some one regarding switching solar charge technique and its calculation etc

IC manufacturers are one of the best sources of information. Datasheets and application notes.
They have plenty of experience and they want to sell their products...
Klaus

 

[aqildad]

thank you KlausST : for your response . i will go through data sheets of manufacturer and then will let you know .. thank you again for the help

 

[aqildad]

sir KlausST : I need your response in this thread https://www.edaboard.com/threads/317575/#post1358273