I am a student and making my final year project in Electric vehicle charging Infrastructure. My unit will use major supply from PVs and rest from grid.

I need to directly charge DC lead acid batteries of 12v, 75Ah.

My question is, Do solar panels have constant voltage output. If so, I can directly connect a 12v panel to battery and time taken to charge will depend on current output.

If not, what is the extra component I need to use to keep battery charge voltage as 12v constant.

Kalayn Dash (

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Best Answer

Dear Mr. Dash,

Good to know that you are working with EVs in India.
Read our post on Electric Vehicles in India:

As for your question, No, solar panels do not have constant voltage or rather current output. Intensity of solar light falling on the panels changes throughout. So, what you need in your project is a “Solar Charge Controller”, this charge controller will regulate the battery charging.

Now, how will you calculate size of charge controller? Use our solar caluclator and set it as 12V:

Have a look at ASC/FSGP 2014:

All the best with your project.

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Thank you for your response.

Currently we are working on the Formula Student Electric competition at Italy this August. We have made our prototype and the final vehicle will be launched soon.

I have already gone through those major articles in your page. I think it is outdated. You need to update the article on electric vehicles in India.

I am working on the charging unit and will go through the charge controller as you have explained. Will update you in case of any doubt.

Thank you.

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You can consider the solar panel from Renesola(,it’s good.

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