Can you Connect a Solar Panel Directly to a Battery?

Many people ask me if it is possible to connect a solar panel directly to a battery.

 The answer is no. 

Now you might be asking, why not?

Let me explain.

Why we should NOT connect a solar panel directly to a battery

  • The voltage of the solar panel is higher than the battery – A typical 12V solar panel will be 18 volts. That is too high to charge a 12V battery which usually get’s charged at 14V. This will lead to heat and fast degradation both in lead-acid batteries and Lithium.
  • There is no way the battery will stop charging – Overcharging any battery is very dangerous and can lead to fire and explosions. Good luck extinguishing a battery fire.

What should you do instead?

Use a charge controller in between the solar panel and the battery.

This device can be PWM (cheap and inefficient) or an MPPT (expensive and efficient). Read my article about PWM VS MPPT.

For more information about connecting a solar panel to a battery, I recommend reading my article on how to do so.

Learn the proper way to connect a solar panel to a battery.

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