What Size Charge Controller For 50w Solar Panel?

Choosing the right charge controller for your solar panels is very important to charging your batteries or battery bank. So in this blog, I’ll help you to choose the right charge controller for your 50w solar panels.

so I’ll share what type of charge controller is best, how to calculate the charge controller size, for 12v & 24v batteries, and if you have multiple solar panels connected in parallel or series connection

for a 12v 50w solar panel a 5A MPPT or PWM charge controller is recommended, Calculate the charge controller size by using this formula wattage/volts = amps + 25% for safety purposes.

I recommend Renogy 12/24v 10A waterproof PWM Charge controller. which will work fine for 12v or 24v solar panels and batteries.

Now I’ll share some calculation formulas so that you can calculate the charge controller size for your solar panels in the future.

How choose a charge controller?

To calculate the charge controller size there are a few things to keep in mind first, the power of solar panels and the size of batteries with their voltage knowledge. (The charge controller size can be different for 12v, 24v, and 48v batteries.

in this case, we have our 50w solar panel which will produce 50 watts of power in peak hours and 200wh in total per day which I have discussed in detail in this article click here to read more

Most of the 50w solar panels come in 12v so you’ll need a 12v battery for your solar panels. to calculate the size of the charge controller we use this formula.

watts/volts = amps + 25%

50/12 = 4.1 + 25% = 5.1A

The 5A charge controller can work with single 12v 50 solar panels to charge a 12v battery, But I recommend a 10A MPPT because they are easy to find and you’ll have more capacity available if you make up your mind future to increase the 50w into 100w solar panels (By either buying an additional 50w solar panel and connecting them in series and parallel)

Most of the experts advise adding an additional 20-25% to the total amps of solar panels which will keep the batteries safe and will give you a little bit more room, and it’s not best for any electronics to run them at their full capacity which can decrease their lifespan.

I have two 200w portable solar panels and I use them in parallel and i use a 50A MPPT charge controller for them. Which is twice the size that is required for 200w solar panels because i use them in parallel which i’ll discuss later on.

Now let’s discuss which type of charge is best for you according to your solar panels

PWM vs MPPT charge controller? Which one?

PWM – stands for Pulse Width Modulation charge controller pulls the solar panel’s voltage down to near the battery voltage

MPPT – Maximum Power Point Tracking Charge controller draws the power at its maximum power by matching  its internal resistance to the solar panel Characteristic Resistance

MPPT charge controllers are 30% more efficient than PWM Charge controllers. So I definitely recommend an MPPT charge controller which may cost a few bucks more but believe they are worth the money.

What Size charge controller for Multiple solar panels

If you have multiple same-size solar panels like 50w solar panels connected in series or parallel you’ll get a different output from them. I have discussed the pros and cons of connecting solar panels in parallel and series

Some quick things If you connect your solar panels in parallel the voltage will stay the same and amps will add up but if you connect them in series then the amps will stay the same and voltage will add up.

which you can choose according to your need and battery voltage size. if you have a 12v battery then connect your 12v solar panels in parallel and if you have a 24v battery connect them in series

e.g if you’ll connect your 2 50w solar panels in parallel then the total output will be 100w, 12 volts, & 8.2 Amps

watts/volts = amps

50+50/12 = 8.2 Amps

you’ll need a 12V 10A charge controller for two 12v 50w solar panels connected in parallel

if you’ll connect them in series if you have a 24V battery then the total output will be 100w, 24V, & 4.1 amps

50+50/24 = 4.1 Amps

24v 5A MPPT charge controller will be enough for two 12v 50 watt solar panels connected in series

by keeping in mind these factors you can calculate the charge controller size for your solar panels for any size and connection.

More tips before choosing a charge controller

What to do if you have different voltage size batteries and solar panels – if you’ll connect 24v solar panels with 12v batteries then the system will automatically decrease its power to match the voltage of the batteries so an MPPT charge controller is recommended in this scenario.

Which will use the maximum power of the solar panels and will adjust internally to match the battery voltage in a result it will give 30% more efficiency than the PWM charge controller in this case. this is why an MPPT charge controller is recommended.

My Recommendation: if you’re looking to store the power from your solar panels into batteries then i would highly recommend a portable power station, which is easy to carry on and you’ll don’t have to deal with the wiring system, buying a charge controller, or inverter. just connect your solar panels with the portable power stations and enjoy your solar power. Jackery Explorer 240 will and best option for 50w solar panel


Choosing the right size charge controller is beneficial to increasing the lifespan of your batteries and charging them properly. for 12v 50w solar panels 10A MPPT charge controller is recommended for multiple solar panels connected in series or parallel.

I hope this blog post is helpful for you, reach out to me if you have any have further queries drop your queries at contact@dotwatts.com. Thank You!

Share This Article

Chris Tsitouris is a renewable energy professional with 10+ years of experience as Director of Engineering at Solar Spectrum, previously working as Project Manager at SunPower and Energy Analyst at the National Renewable Energy Laboratory. As a thought leader, Chris has authored numerous articles and research papers.

Leave a Comment