Battery For 200W Solar Panel (What You Need)

A 200W solar panel offers various power applications from small fridges to laptops and smaller devices. But, to take advantage of the power this panel can generate in a day, you should have a battery attached.

You can use a single 100ah lithium-ion battery or two 100ah lead-acid batteries wired in parallel with a 200W solar panel. The best battery for a 200W solar panel would be a 100ah lithium-iron battery. Lithium-ion batteries would be superior in terms of lifespan and performance.

When looking at a battery for a 200W solar panel, a few elements need to be understood, and those would be:

  • What level of power generation can a 200W solar panel achieve in a day
  • What kinds of battery you could use for a 200W solar panel
  • Where could you use a 200W solar panel and battery

Armed with this information, you can utilize the power generated and supplement the continuous supply to connected devices.

How Much Power Can A 200W Solar Panel Create In A Day?

With five hours of solid sunlight, a 200W panel can generate 1000W of power daily, enough to charge a 12V battery or power other connected devices.

The ability of solar panels to generate power is defined by how much direct sunlight they receive during the day. Also, there are peak hours of a generation where the power generation is much higher.

The peak power generation time coincides with the perihelion –when the sun is at its highest in the sky and directly overhead –where the most power can be created as the solar intensity is maximum.

The lowest generation times are between 6 am, 9 am, 5 pm, and 7 pm, with 0W and 50W, generated. Between 9 am and 11 am and 3 pm and 5 pm, that level increases to 50W-100W.

But between 11 am and 3 pm, the 200W panel achieves its maximum capacity. Generating between 170W-200W from 11 am and 1 pm, then 200W dropping to 100W from 1 pm-3 pm.

It’s important to know the peak times as it will give your optimum battery charging times during the day, and whether you have one or two batteries connected, the chances are that both will be fully charged by sunset and ready to use overnight.

What Battery Should You Use For A 200W Solar Panel?

You can use a cheaper sealed lead-acid battery, while a lithium-iron-phosphate battery would last longer and perform better but is more expensive.

We know that a 12V 100ah battery would be optimal for the 200W solar panel, but depending on what you are prepared to spend will dictate the type of battery you buy. The modern lead-acid batteries are much improved, but they have issues around capacity cycles.

It is recommended that a lead-acid battery is never discharged below 50% as this will significantly affect the number of charge cycles it can complete and reduce its performance.

This limits the battery performance, and should you discharge it below 50% too often, you will replace them far quicker, which will cost more. Even though they are cheaper than lithium-iron, replacement costs will add up.

Lithium-ion batteries are about three times more expensive than lead-acid ones. Still, they can discharge to 80% (or more) without degradation and have thousands of charge/discharge cycles before needing replacement.

Where you can rather opt for lithium-ion batteries for your 200w solar panel.

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See also: Best Solar Batteries: Top Picks and Comprehensive Buying Guide for 2022

A Quick Word On An Inverter & Charge Controller

You need an inverter and a charge controller for a solar system to operate. The inverter allows you to power AC devices using DC stored in the batteries. It converts the DC to AC to use your laptop, wifi router, chargers, and other AC-powered devices from your battery.

When looking at an inverter, you need to know the total wattage requirement and get one to match it.

If you are running DC devices like some camping fridges, you could connect that directly to the panel, and as long as you have sunlight, your device will run. Bear in mind that clouds and shade will all decrease power generation levels.

The charge controller regulates the charging current and voltage from the panels to the batteries and ensures they don’t overcharge, leading to diminished performance.

Where Could A 200W Solar Panel Be Used?

The 200w solar panel generates a respectable level of power, often used in RVs, boats, and camping.

The 200w PV system is a mid-level setup that generates enough power to make outdoor living entirely sustainable. Because the panel is not massive and only covers around 11 sq ft, it can be mounted to an RV or boat roof or used on a ground mount at a campsite.

It could easily power coolers, laptops, small pumps, electric fans, and connected led lights with suitable batteries. You could add another battery and panel to boost this capacity.

Where you set up your solar panel is essential, so you need to avoid shade at all costs as you need maximum solar exposure during the day. Also, ensure your panel is clean, as dust and dirt will affect the light striking the surface and reduce the generation capacity.

To this end, opt for portable solar panels, so you can sit in the shade while your panels bask in the sun. If needed, they are much easier to move around at a site and pack up and transport when you leave.

How Much Would 200W Solar Panels & Batteries Cost?

For a fixed panel, you would be looking at around $230, while the portable ones would cost about $430, while a sealed lead-acid battery would be around $130, with a lithium-ion battery priced at around $200.

As demand for lithium-ion batteries grows, they are becoming cheaper. While the price difference is not as significant as it was, they are still more expensive than lead-acid batteries.

But it will be worth the additional investment if you only have to invest an extra $50-$150 for a good quality lithium-ion battery.


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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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