What Can You Run With a 50 Watt Solar Panel?

What Can You Run With a 50 Watt Solar Panel? - Featured Image

You would like to know what can you run with a 50 watt solar panel?  This type of panel is small but it will produce enough power to run appliances and devices. Especially for campers and for those wanting to provide power where there isn’t an electricity hook-up.

You may be thinking, is a 50 watt solar panel powerful enough? Or I like its weight, size and price but what can I do with it? Or you might be thinking. “I want to be greener and eco-friendly and it seems like a 50 watt panel might be a good starting place”

In this post I will be answering some of those questions about 50 watt solar panels. I hope by the end of the post that you will have a better handle on the panel’s potential uses.

What Can You Run With A 50 Watt Solar Panel?

“A 50 watt solar panel is designed to charge batteries; this means it won’t directly run an appliance. Except maybe a very small USB device like a fan if the panel has a built-in USB port. The USB port can also be used to charge smaller electronics like smartphones. But it won’t run an appliance directly unless the appliance has a built-in rechargeable battery”. 

What Can You Run With a 50 Watt Solar Panel? - Mobile Phone

If you are new to solar power you might find this information disappointing. Because you thought you could just plug an appliance like a mini fridge straight into the panel. But the battery you are charging with the 50 watt solar panel will run appliances. So all is not lost.

You might be new to solar power. So you may have looked at information about it written by so-called experts. I like to call them “high brows”. This is because they write or talk in a language the average person doesn’t understand. 

This puts people off solar technology because it seems too complicated and “techie”. I promise I will try to keep it plain and simple. There is a bit of math involved but it is not difficult to understand.

What Batteries Can I Charge With A 50 Watt Solar Panel To Run Or Power Appliances

This is a video from ChickenShipp Farms and Outdoors It shows the Renogy 50 watt Monocrystalline 12v Solar Panel Kit Installed on their 1971 Tanzer 22 Sailboat

There are 2 types of battery you can charge with a 50 watt solar panel to run or power appliances. They are Lead-Acid and Lithium deep cycle batteries. Just to make the distinction these are not the same type of battery you would find in your car.

MK Battery Say; 

A deep cycle battery is a battery that is designed to produce steady power output over an extended period of time, discharging the battery significantly, at which point it must be recharged to complete the cycle.

By contrast, a regular car battery is designed to provide a momentary burst of energy, typically enough to get your car started, before handing off power production to the alternator. In this case, the battery is not designed to be cycled because it should be kept fully charged at all times. (Source; mkbattery,com)

Throughout the post I will be using 12 volt deep cycle batteries in all examples. There are other voltage batteries available like 24 volt but you don’t need to worry about them here. 

12V Lead-Acid Batteries

There are several lead-acid battery types you can use a 50 watt panel to charge. Here are some of the most popular;

  • Flooded
  • Gel
  • AGM (Adsorbed Gas Mat)
  • Calcium
What Batteries Can I Charge With A 50 Watt Solar Panel To Run Or Power Appliances

12V Lithium Batteries

Again there are several types of Lithium batteries but here are some of the most popular;

  • Lithium Iron Phosphate (LiFePO4)
  • Lithium-Ion
  • NMC (Lithium Manganese Cobalt Oxide)
  • Lithium Titanate

The solar panel doesn’t charge the batteries directly; this is because there is a big risk of overcharging. So a solar charge controller is used to stop this from happening. 

If you would like to read more about charging lithium batteries with solar panels you can here;

Related == >>>>>>>>>> Can You Charge A Lithium Ion Battery With A Solar Panel?

How Do You Work Out The Size Of Battery A 50 Watt Solar Panel Can Charge?

I mentioned earlier that the “high brows” like to make it look complicated but in reality it is simple. Using the formula I am going to outline. You will be able to calculate the size of battery any solar panel will charge.

But remember these calculations are based on known variables and best performance under full sunlight. When there is a fluctuation in sunlight for example in cloudy or hazy conditions. The performance of the solar panel will be affected along with the accuracy of the calculations.

It All Starts With Sun Hours

We are going to assume it’s summer when the best sun hours occur between 11am and 4pm. This means the sun is directly above the 50 watt solar panel enabling optimum sunlight collection.

How Do You Work Out The Size Of Battery A 50 Watt Solar Panel Can Charge? -Sunshine

So that is 5 hours of direct full sunlight. There are other hours of sunlight in the day when it can be collected. But we are going to ignore those for the moment and concentrate on full sunlight. 

Finding the Number of Amps 

Deep cycle battery capacity is measured in amp hours (Ah). So to recharge the battery and bring it back to it’s full amp hour capacity. The used amp hours (discharged) have to be replaced. This is where our 50w solar panel comes to the rescue.

But you may have noticed that a solar panel is measured in watts and volts not amps. So how do we find out the number of amps it will produce? A little bit of detective work is needed by going into the solar panels specifications.

You can usually find solar panels specifications on the manufacturers website. Look for the panel’s maximum power voltage (VMP). In this case we will use the GrapeSolar 50 watt 12V Monocrystalline Flexible panel’s VMP. Which is 17.6V we then divide the VMP by the solar panel watts which are 50.

Multimeter showing Amps

This calculation 50 ÷ 17.6 = 2.84 this is the number of amps the panel will produce under full sunlight. 

It’s All About Time

We now know that our sample 50 watt solar panel will produce 2.84A under full sunlight. But to find the number of amps the 50w panel will recharge a battery during full sunlight hours. We need to multiply time the number of sun hours (5) by the amps the panel produces (2.84)

That equals 14.2. This means that our 50w solar panel will recharge a deep cycle battery by 14.2Ah during full sunlight hours. Hang on, what about the other sunlight hours in the day?. Well the sun can be much weaker in the early morning and evening. 

It's All About Time

But those sun hours do exist so it would be reasonable to add an extra sun hour (2.84Ah) into the calculation. The new calculation being 14.2Ah + 2.84Ah = 17.04Ah. Meaning that we are saying that on a typical sunny summer day in ideal conditions. Our 50w panel will recharge a battery by 17.04Ah 

If you would like to read more about 50 Watt solar panels and battery amp hours. You can by following this thread;

Related == >>>>>>>>>> How many amps does a 50 watt solar panel produce? 

What Size 12v Battery Will a 50 Watt Solar Panel Charge?

We know that a 50 watt solar panel will recharge a battery by 17.04Ah per day during the summer. That is all well and good but how does that relate to the battery size it can recharge?

Charging Lead-Acid Batteries With A 50w Solar Panel

You might not know that you can only discharge (deplete) a lead-acid battery by 50%. Anything more than that and you will damage the battery and consistent overcharging will destroy it. This means that if you have a 50Ah battery you can discharge it to 25Ah but no lower. 

A 50 watt panel will recharge by 17.04Ah and a 50Ah lead acid battery could be discharged by 25Ah per day. This is a recharging deficit of -7.96Ah per day. I think you can see that it is not capable of keeping a 50Ah battery recharged.

Varta Lead Acid Battery

I know you are thinking but I might not use that many battery amp hours per day. This is true but in the real world ideal sunlight conditions are rare. On a cloudy day you can produce as little as 20% of the amp hours of a sunny day around 6.82Ah.

So let’s be realistic. At a pinch you could use a 50 watt solar panel to recharge a 50Ah battery. if it was regularly discharged by 25% that’s 12,5Ah per day and no more. But it is more suited to recharging a 30Ah lead-acid battery.

This is because a 30Ah lead-acid battery discharged by 50% is15Ah. And the solar panel can recharge by 17.04Ah. That is a plus of 2.04Ah so at least there would be some room for error in the charging calculation. 

Charging Lithium Batteries With A 50w Solar Panel

A 50Ah lithium battery can be discharged by more than 50%. For instance a LiFePO4 battery can be discharged to 10% (5Ah) without any problems. This means if you were to discharge it down that far it would require 45Ah to recharge it. 

Again you can immediately see that a 50 watt solar panel isn’t capable of recharging it. A 50w panel would be more suited to recharging a 20Ah LiFePO4 battery. 

Renogy Smart LiFePO4 Battery
Renogy Smart 12V 100Ah LiFePO4 Battery

There is some good news though. You can use a 50w panel with larger sized batteries to keep them topped off.

If you would like to take a peek at my LiFePO4 battery review you can do so here;

Related == >>>>>>>>>> Renogy Smart Lithium Iron Phosphate Battery Review 12V 100Ah

What Can You Run With A 30Ah Battery And 50 Watt Solar Panel?

So the real question should be what can you run with a 30Ah battery and 50w solar panel? I have already mentioned that it can be used to keep larger batteries topped off. But the kinds of things you can run with this combination are;

What Can You Run With A 30Ah Battery And 50 Watt Solar Panel? - Portable TV
  • Lights
  • Fans
  • DC TVs
  • Electric Blankets
  • Air Pumps (4 Hours)
  • Mini Fridges (4 Hours)
  • Charging Laptops

As I mentioned earlier, charging small electronic devices such as smartphones, cameras and tablets. You can also attach the battery to a 200 watt inverter to provide some AC power. Or you can connect the panel to a 100wh to 250wh Portable Power Station

My Closing Thoughts

A 50 watt solar panel charges a battery and the battery powers or charges appliances. The calculations to find out what size battery to use with the panel are not that difficult. You don’t even need to be “techie” or a math genius to understand it. 

The differences between lead-acid and lithium discharge capacities can lead to a little bit of confusion. Because the 50w panel’s charging capability is different for each battery type. The battery capacities the panel can handle may be a surprise to you. But the 50w solar panel does have it’s uses,

If you would like to take a look at some 50 watt portable solar panel specifications and descriptions you can here;

I hope you enjoyed this post and have found it helpful. If you have any questions about 50 watt solar panels and what it will run. Or want to leave your own personal review, please feel free to leave a comment below.

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4 Comments on “What Can You Run With a 50 Watt Solar Panel?”

  1. Thank you for sharing this information.  This looks like a perfect solution for what I need for my trailer.  I have a large generator but I do not always like to take it due to the weight and size.  I’m good with battery power when I’m not using the AC but when the battery gets low on juice it does not have enough power to bring the tip-out back in.  With this, it seems like it keeps the battery charged enough to last through a trip. 

    1. Hi Mike 

      Yes portable panels can be used for that purpose. Just check the battery size as on average a 50 watt panel will only recharge by about 15Ah amps per day.

      If you regularly use over 15amps per day and your battery is more than 30Ah. You might want to consider a larger solar panel like a 100 watt. which on an average sunny day  will produce between 22Ah and 30Ah 

      Regards

      Steve 

  2. What a fascinating article!

    Every so often we ponder getting the sort of solar panels that go on our roof but I believe our roof sloops in the wrong direction for this to be worthwhile for the time being.

    I hadn’t thought about portable solar panels until coming across this article. I have a couple of friends with camper vans and I am wondering if these might be of interest to them. The prices are certainly pretty reasonable.

    Just being able to charge our laptops, gadgets etc. on the move would be interesting. Can they be attached to cars? Or is that impractical?

    All the best,

    J

    1. Hi Julia strictly speaking it is possible to attach a solar panel to a car there are examples out there. Bout currently from a practical point of view the answer is no. But you can carry a portable solar panel and power station in your car. This would allow you to generate electricity when you are out and about. 

      Regards

      Steve

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