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How Electricity Really Flows - A Beginner's Guide 1

Ever wonder how the magic juice gets from your battery to your headlights? Let me explain how electricity travels through wires in easy-to-digest terms.

How Electricity Really Flows - A Beginner's Guide 1 ->

How Does A Solar System Work? - Beginner's Guide 2 ->

Different Options For Solar Energy Systems - Beginner's Guide 3 ->

How Electricity Really Flows

How does the electricity transmit?

There are two main ways electrons move - DC(Direct Current) and AC(Alternating Current).

Let's take a look at this battery. There's a positive(red) and negative(black) terminal, you connect it to an appliance while attaching two wires to both terminals of the battery.

While it's connected, the electricity will flow in one direction and it goes out one side of the battery to the appliance and flows out of the appliance back to the battery.

This is a typical DC(Direct Current) system, think of it like a lazy river, the electricity flows in one direction from the battery to whatever needs power. Your car's battery uses DC to keep things humming.

The AC(Alternating current) system is more like ocean waves crashing on the beach. Instead of a steady flow, the positive and the negative are switching at a very high frequency(e.g. 60Hz in North America), the electricity is actually vibrating in an AC system.

But don't worry, it's not a physical vibration so the wires won't vibrate. Technically it's called oscillation. The oscillation transmits power across distances, that's how the grid brings electricity to your home. It means in an AC system, there is no positive and negative, the electricity is being transmitted through vibrations(or oscillation), so there's no flow at all.

If the DC system is like a river and flows in, in an AC system, the direction electricity flows reverses rapidly, like a wave going across an ocean, the wave transmits over distance in an ocean, the force moves but the ocean does not.

Conclusion:

In a DC system, the electricity flows continuously through the wire in one direction.

In an AC system, the direction electricity flows reverses rapidly that it vibrates to transmit the electricity.

Understanding electrical measurements

Now we know how electricity transmits, let's talk about how to measure the electricity. By the nitty gritty - Volts, Amps & Watts.

Voltage is the force of the electricity, it measures the electrical pressure. The electricity is very similar to a garden hose with water and the voltage is the pressure of the water.

Whether the water is flowing through the hose or not, the pressure is constant like the voltage is always there. Because the voltage is the energy potential or how much force is ready to be used, it can tell you what appliances you can hook up to your electrical system.

If you have a 12-volt appliance, you can hook up to a 12-volt battery, same as a 110-volt appliance hook up to a 110-volt battery, you can think of voltage as a way to understand compatibility.

Amperage is the rate of electrical flow, the amp rating will determine how big the wire needs to be when attaching electrical components.

In the garden hose example it will be the thickness of the water hose, the thicker it is the more water can go through.

If you have a 24-volt appliance, you can hook up to a 24-volt battery, and you will need a wire that is large enough to carry the number of amps required for that load.

Watts is a combination of volts and amps, it's simply the voltage times amperage and that will tell you the total amount of electricity going through a system, and shows you how much power overall it's generating or consuming.

Let's do some simple calculation, now we have a solar panel that produces 10 volts but only 1 amp, that means that volts times the amps you will have 10 volts x 1 amp = 10 watts.

If the sticker on the back of an appliance shows the wattage and the voltage but doesn't tell you the ampere, now you know how to figure it out.

On your electricity bill, it will tell you how many kilowatt hours or thousands of watts of hours you have used, that's the wattage times the hours, what are called Watt-hours.

If you use 100 watts for one hour, that's 100 watt-hours.
If you use 1,000 watts for one hour, that's 1,000 watt-hours or one-kilowatt hour/1kWh.

It's very simple in the watt-hour to understand how much electricity an appliance is generating or consuming over time, or use watt-hour to determine how much electricity a battery can store.

If you have a thousand-watt-hour storage battery and want it to power a 50-watt load, we can take thousand-watt hours and divide it by 50 watts, then we know how many hours it can power for, which is 20 hours.
Let's do a second example, we have a 100-watt hour battery and we want to power a 20-watt load, we can do it for 5 hours.

Conclusion:

Use volts and amps to figure out the wattage, then use watts with time to figure out watt-hours.

Watt-hours is the best metric to determine how big a battery is, how long it takes to recharge, how long you can use that battery to power your loads and everything else.

The amp-hour rating only applies to that stated voltage, but you have some flexibility to change the voltage and current levels. By using different wiring configurations between components.Before we move forward, let's take a look at these batteries for a sec.

Like this 12-volt battery, it has 200 amp-hours, that means that it can produce 200 amps for 1 hour at 12 volts.

Here's another battery that shows 6 volts and 225 amp-hours. Again, that means that it can produce 225 amps for 1 hour at 6 volts.

The amp-hour rating only applies to that stated voltage, but you have some flexibility to change the voltage and current levels. By using different wiring configurations between components.

This brings us to parallel and series connection systems. By joining up batteries, solar panels or other electronics in specific ways, you can manipulate how the voltage and amps are distributed.

What is Parallel & Series Connection?

Parallel Connection means connecting all the positives to one wire and all the negatives to another wire, like widening a river - more can flow at once without changing pressure.

In a parallel connection, the voltage or the pressure of electricity will not change, but the amps will beef up.

If you parallel connect all of these 3 solar panels and each one produces 6 amps, you will get 18 amps.
It shows in parallel connection, the amps will go up and the voltage stays the same as 18V.

Series Connection means you connect the positive of one to the negative of the one next to it, like making a string or a daisy chain of these panels end to end - the river gets longer with the same flow.

In a series connection, the voltage will rise but the amps will stay the same.

Let's say we still have those same 3 solar panels and they all produce 6 amps. Instead of producing 18 amps with a parallel connection, they will still only produce 6 amps with a series connection, but the voltage will go up.
All together when series connected, they will produce 18 volts instead.

So you can change the voltage and the amp rating of certain components including batteries and solar panels by connecting them in various ways.

Conclusion:

In summary, parallel connection combines components for increased current, while series connection increases voltage.

Over the last guide, we know how the electricity flows, how to compare batteries, and how to distribute Voltage and Amperage.

With these basic concepts, now we can design a solar power system from scratch. So first, let's talk about what are the main parts of a solar system.

How Does A Solar System Work?

The main parts of a solar system

Battery

The battery is the heart of the solar system, it stores electricity. The type of battery used can vary, with common options including lead-acid, lithium-ion, and others. Each type has its advantages and drawbacks, such as cost, capacity, weight, and maintenance requirements.

We'll introduce each type of them in the future, but now let's say we're gonna build a budget and easy-to-understand solar power system, so we gonna build a 12V solar power system, we're using three 12V(Volts) 100AH(Amp hours) lead-acid batteries.

Because it is a 12V solar system, these batteries are going to be in parallel, the amp hour would be 100+100+100=300AH at 12 volts.

Let's figure out the capacity of these batteries, so if we multiply the amp hours and voltage, we will get 300AH x 12 volts = 3600Wh(watt-hours).

But because these are lead-acid batteries, it can only be discharged to 50 percent for a long life span, so we need to cut this figure in half which is 3600Wh(watt hours)/2 = 1800Wh.

Let's say we have a 100 watt load appliance that we want to power with this system, because we have 1800Wh available in our batteries, we can divide it by 100 watt and we'll get how many hours we can run it for, which is 1800Wh/100 watt = 18 hours.

Solar Panels

After we select our power bank(battery), we need to charge it with solar panels. In simple terms, solar panels consist of photovoltaic(PV) cells that convert sunlight into electricity.

There are various types and figures of solar panels. For better understanding, we're gonna use a solar panel that says 19.8 volts and produces 5 amps under ideal circumstances.

Combine those figures it will give you 99 watts, we're gonna use 4 of them together for better charging efficiency, it will be 4 x 99 watts = 396 watts.

If you want to figure out how long it will take to charge up the battery with these panels, we need to take the watt hours of the battery bank and divide it by the wattage of the solar panels. So if the battery bank is 1800 watt hours we can recharge it with a 396 watt solar panel array in 4.54 hours in ideal circumstances.

But because solar panels typically output only around 70% to 80% of rated wattage, so we will take 396 watts multiplied by 70% or 0.7, then we will get 277.2 watts. So realistically, it will take 6.49 hours to recharge the system under most realistic circumstances with solar panels.

Solar Charge Controller

Now we need to figure out what size solar charge controller we need, but before, what is solar charge controller and what is it for?

So the solar panel creates electricity, but it comes in at a weird voltage. For this 12-volt battery to charge, it needs to be at a very specific voltage which is 12-volt.

That's why we need a solar charge controller. It evens out the power coming from the solar panel, regulates the voltage so that this battery can charge safely, and protects the battery from being overcharged or excessively discharged to reduce the lifespan of the battery.

It also has all sorts of other special features, especially what's called an MPPT charge controller, and temperature compensation. All these different functions are designed to make sure that this solar panel power goes into the 12-volt battery in a safe and efficient way.

Getting back to our solar system, because solar charge controllers are rated in amps, we need to figure out how many amps our 19.8 volt solar panels set will actually produce at 12 volts.

We're gonna take 396 watts, which is the total solar panel array wattage, and divide it by 12 volts. This will tell us how many amps our solar charge controller needs to be able to handle, so 396 divided 12 would be 33 amps, that means we need a solar charge controller that is slightly bigger than 33 amps.

So we need a 40 amp solar charge controller, this will also allow us to add an extra solar panel in the future if we want to. It's always better to size your solar charge controller larger than you need.

When designing a solar power system, it's essential to calculate the total energy needs, decide on a suitable battery capacity to ensure energy availability during periods without sunlight, and select a properly sized solar array and charge controller to replenish the battery while protecting it from damage. Additionally, other components like inverters (to convert DC to AC), fuses, and wiring must be appropriately sized to handle the system's power requirements safely.

Conclusion:

Designing a solar power system requires understanding the key components: batteries, solar panels, and a solar charge controller. The Battery stores the energy, the solar panel converts sunlight to electricity, and the solar charge controller regulates voltage for safe battery charging.

How to use the electricity in the battery?

Inverter

As we know from the previous guide, the solar system is running on DC or Direct current, but most of our household electricity appliances are running on AC or Alternating current. To use the electricity in the battery, the most critical component you need is an inverter.

The inverter is basically an AC power creator, it converts the DC(Direct Current) electricity from solar panels or stored in the battery into AC(Alternating Current) electricity, which is the standard electrical current used in most homes and businesses for powering appliances and electronics.

Another thing you should know is that each of the inverters are designed to work with the precise voltage range of the DC input, 12V DC input can only use a 12V inverter. Also, a 12V inverter can not be connected to any other battery, except a 12V battery.

The inverter is rated by watt as the output, there will be continuous wattage and surge wattage, these are the metrics you should focus on when sizing your inverter.

Continuous wattage refers to the amount of power that a device can produce or sustain for an extended period. This is the standard operating level that the inverter or generator can handle under normal use. When you're selecting equipment, you should ensure that its continuous wattage rating meets or exceeds the total wattage of all the appliances and devices you plan to run simultaneously.

For example, if you have a refrigerator that uses 200 watts, a TV that uses 100 watts, and lights that use a combined 100 watts, you would need an inverter or generator with a continuous wattage rating of at least 400 watts to power all of these at the same time.

Surge Wattage (also known as Peak, Startup, or Starting Wattage) is the amount of power that a device can produce over a short period to start motors or appliances that require a larger startup current. Many electrical devices, especially those with induction motors like refrigerators, air conditioners, and pumps, require a higher wattage for a brief moment to start up than they do to run continuously.

Surge wattage is typically much higher than continuous wattage and can often be two to three times the continuous wattage requirements. This surge capacity is only available for a few seconds to a few minutes, depending on the device.

For instance, if a refrigerator may require 600 watts to start (surge wattage), but then levels out to 200 watts during continuous operation (continuous wattage), you need an inverter or power source that can handle at least a 600-watt surge.

There are two main types of inverters: Modified Sine Wave Inverter(MSW) and Pure Sine Wave Inverter(PSW).

To figure out the difference, we need to know that the modified sine and pure sine referred to waveform at the AC output of the inverter. That is the voltage when plugged in overtime, how smooth that curve is.

The metrics that we use to measure it is THD: Total Harmonic Distortion, THD is used to characterize the purity of the AC voltage and current waveforms.

The THD(Total Harmonic Distortion) of the grid is less than 5%, and for PSW(Pure sine wave inverter) even less than 3%.

However, the THD of MSW(Modified sine wave inverter) can reach 20% to 40%, it is very noisy and produces choppy waveform, most importantly it can negatively affect how your appliance works, we do not recommend using MSW(Modified sine wave inverter) even it's cheaper.

We recommend Pure Sine Wave Inverter, it can produce a smooth and consistent wave of power that is equivalent to, or even better than the power from the grid. It may cost more money but it is suitable for basically every sensitive electronic device and a long run choice.

The standard energy efficiency of the inverter is around 80-90%. And of course, the more money you spend, the higher efficiency you get.

Conclusion:

To utilize solar-generated or battery-stored DC electricity in our AC-dependent homes, an inverter is essential. It transforms DC into AC, matching the required voltage range and wattage needs of household appliances. Pure Sine Wave Inverters are preferable over Modified Sine Wave Inverters due to their ability to produce a smoother waveform, ensuring compatibility and longevity for sensitive electronics despite their higher cost.

How to connect these components safely and efficiently?

Wiring and fuses are essential components that ensure the safe and efficient operation of the solar power system. But how to size a fuse and the wire gauge for your solar system and appliance?

Let's start by understanding what fuse and wire gauge are.

The fuse is a small wire that heats up at a certain amp rating, if too many amps go through, it will disconnect that appliance or the wire. So the fuse is like a self destructive switch, it will disconnect power if something bad happens to that wire or the appliance short circuits internally.

Whenever you connect an appliance or a charger to a battery, the battery is an amp source, it can produce hundreds of amps so you need to make sure that it's protected.

All of that electricity flows out through the wires of your solar system, it will generate lots of heat and catch things on fire, that's why you need to size the fuse and the wire gauge size accordingly for your application.

Now, let's learn what size wire to use in what size fuse, and how to calculate that.

Fuse

We need to find the size for the fuse so it can be able to protect the appliance and the wire itself.

In order to do this, what you can do is size the fuse to 125% of the amp rating.

There are different codes, such as 135%, but 125% of the amp rating is easy and most people agree that it works for most things. So in the short term, take the appliance amp rating and times it by 1.25, it will give you the amp rating of the fuse that you need.

Keep in mind that since all wires give off a small amount of heat, there is a loss of 3% to 5%, which is the conventional efficiency.

Also, if you have an appliance that's connected to the battery, and it's always turned on like an inverter, standby or a solar charge controller, all you need to do is make sure that the gauge of the wires is larger than needed for better efficiency and less loss. If your load is infrequently connected you can use a slightly smaller wire but you still need to make sure that the fuse is large enough.

Wire gauge

Correct wiring is critical for any electrical system. We need a wire to connect your appliance to a battery, so first we need to determine the distance of the wires, and the amperage the wires need to carry.

With these two variables, we can follow the chart below and it will tell you what gauge of wire to use for that size of load at that distance.

Keep in mind that if you use a wire that's too small, it will give off more heat and will not be as efficient. But if you use the proper gauge of wire and you also calculate to 125% of the amp load the wire, the appliance should be protected.

Always ensure that each component is correctly sized and rated for the system's power requirements and that the installation complies with local electrical codes. It is often best to work with a certified electrician or a solar installation professional to ensure that your system is safe and reliable.

Conclusion:

Sizing fuses and wire gauges correctly is crucial for the safety and efficiency of a solar power system. For fuse size, we recommend rated at 125% of the appliance's amp rating to protect against overcurrent. For wire gauges, the choice depends on the amperage and the distance the wire must cover, with the aim to minimize heat loss and maintain efficiency. We recommended consulting the chart to determine the correct wire gauge, and to always adhere to local electrical codes, potentially enlisting the help of a certified electrician for safe and reliable system installation.

Different Options For Solar Energy Systems

12V, 24V, and 48V: Which Voltage Is Best for Your Solar Power System?

Over the last guide, we know how many components we need in a solar power system. Now let’s dive into the solar power system, to see how many different options there are in solar energy systems.

Understanding Your Energy Needs and Loads

Before diving deep into voltage, it's important to get clear on your energy needs. The power demands of your gear - like appliances, devices, etc - hugely impact how your solar setup is designed and sized.

When it comes to batteries, the voltage plays a major part in determining how much juice it can store. You calculate a battery's energy storage using this formula:

Let's compare these batteries head to head, we've got three batteries with the same amp-hour rating of 200Ah, but different voltages of 12V, 24V, and 48V.

As you can see, the higher voltage batteries store more energy even with the same Ah capacity. This means that for a similar load, the 200Ah 48V battery will provide backup power the longest compared to the others.

let's geek out on system efficiency for a sec. As the formula P = VI (Power = Voltage × Current) tells us, higher voltage allows the same power to flow with less current. Less current means lower resistance losses as the power travels through your wires and components.

To really drive this home, let’s assume your total energy demand of 5000W, we can calculate the currents for each system using the formula.

You can see how slashing current like that leads to better performance and less wasted energy, the 48V setup is the efficiency champion in this scenario, understanding these principles will help you optimize your system for maximum power and lower cost.

Which Voltage You Should Choose

Higher voltage does boost efficiency by reducing power losses as current flows through your system. But selecting the optimal voltage involves balancing many factors - you have to consider the big picture.

The relationship between voltage and performance can seem complicated, but let us break it down simply.

For energy needs under 1,500 watts:

A 12-volt configuration is typically sufficient and affordable. Ideal for RVs, boats and EVs where demands are lower.

1,500 to 5,000 watts:

A 24-volt setup provides better performance and efficiency for medium loads systems with moderate power requirements.

Over 5,000 watts:

48 volts is most cost-effective and space-efficient for large residential or commercial/industrial systems with higher power needs.

Main Types Of Solar Batteries

After selecting your desired needs, loads and the optimal voltage, we can start moving on to the next step, selecting the most important part of the solar system: the battery.

Solar batteries preserve harvested sunlight to be utilized later as needed. With these backup reserves need not fear power interruptions from storms or outages on the grid.

There are a lot of types of batteries such as, but we are going to discuss the most common and main types of batteries.

Lead-acid

Lead-acid batteries have the longest history in the solar industry. Renowned for their reliability and value, these batteries remain a popular choice. However, lead-acid batteries can only sustainably discharge to 50% capacity before lifespan is impacted, so careful charging and management is important.

Lead-acid batteries come in two main types: flooded and sealed.

Flooded Lead-acid

Flooded lead-acid batteries offer the most cost-effective entry point. They are called “flooded” because they contain a liquid electrolyte solution of sulphuric acid that floods the lead plates inside the battery.

Some advantages are its strong suiting of high-current demands and tolerance of cooler charging climates. Wide availability and recyclability and also make flooded lead units practical in many regions. Reliability is generally good as well.

On the other hand, that electrolyte brings high maintenance needs, like periodic distilled water topping to replace evaporation. Life expectancy also tends to be the shortest of the lead types, and has some performance weaknesses that you have to design around such as voltage sagging as the battery discharges.

Sealed Lead-acid

Slightly more costly than flooded lead-acids are Absorbent Glass Mat (AGM) and gel cell batteries, collectively known as sealed lead-acids. By hermetically sealing the acid within a saturated glass mat or jelly-like medium, these models offer a lower lifetime cost through reduced servicing. Their enclosed construction also eliminates the risk of acid spillage for safer handling.

These batteries don't require the same level of maintenance as flooded lead acid and lasts slightly longer in terms of cycle life, but the performance is usually pretty much the same or maybe very slightly better than flooded.

Pros:

Affordability

Safety

Reliability

Temperature adaptability

Cons:

Bulky and take up a lot of space

Limited lifespan: Typically last 3-5 years

Maintenance Require

Slow charging & discharging

For budget-focused off-gridders unconstrained by space/weight, lead-acid batteries offer a time-tested balance of affordability and functionality.

Best For: An off-grid system or backup power during power outages.

Lithium-ion

Lithium-ion chemistry has emerged at the forefront of residential solar storage thanks to advancing technology lowering costs. Offering mid-range power alongside a more competitive price tag, lithium has become a staple option.

It facilitates greater energy utilization by allowing up to 80% depth of discharge without life span impacts - a marked improvement over the 50% ceiling for lead-acid. Faster recharging cycles are another boon.

Under the hood, a lithium pack consists of multiple cells wired together to achieve higher voltages or capacities as required. They are lightweight and portable, making them ideal for applications where mobility is required.

Pros:

High Energy Density

Longer Lifespan: Last up to 10 years or more

Fast Charging

Cons:

Safety Concerns

Temperature Sensitivity

Recycling Challenges

As adoption grows, lithium-ion is proving itself a high-performing renewable enabler. While upfront outlay still exceeds lead alternatives, total savings on energy bills and maintenance over the battery's multi-year lifespan helps justify the investment for suitable homes.

Best For: Residential and mobility solar installations.

LiFePO4

As a subset of lithium-ion batteries, LiFePO4, or lithium iron phosphate, has rightfully earned its reputation as the premier residential solar battery. Composed of lithium, iron, and phosphate ions, its enhanced chemistry delivers unmatched safety, performance, longevity and price relative to competitors.

This chemistry has been heralded by experts as ideally suited for both stationary solar arrays and portable power units alike, such as the versatile OUPES Mega 5. LiFePO4 cells truly excel in off-grid and industrial applications demanding all-day power in compact form factors.

Key to its acclaim is LiFePO4's improved safety resulting from its inherent thermal stability. This, combined with extended lifespan, temperature tolerance, and energy density, makes it the go-to for applications where protection, dependability and energy optimization are priorities. Some of its core advantages include:

Pros:

Reduced fire risk even under extreme conditions

Higher cycle counts of 1500+ charges

Wider operational temperature range

Lighter weight for mobility

Stable voltage output during discharge

Fast charging

Cons:

Cost More

Lower voltage

In short, for homeowners or adventurers seeking a renewable energy partner as safe as it is powerful and enduring, LiFePO4 batteries are a sure bet worth considering. Their reputation for reliability in stationary and mobile use cases is well-deserved.

Best for: Portable solar power systems, backup power, EV, and other solar energy applications.

Nickel-Cadmium Batteries(Ni-Cd)

While rarely seen in homes due to size and costs, Ni-Cd batteries remain popular for commercial/industrial solar thanks to their durability. Capable of deep cycling 80-100% daily with minimal life impact, they deliver reliability over massive charge/discharge volumes.

However, their energy density leaves something to be desired. Additional weight and bulk are tradeoffs for longevity - with lifespans reaching an impressive 20+ years.

Other downsides include higher self-discharge when idle compared to competitors. And upfront costs, while below lithium, can still challenge certain large-scale budgets.

Pros:

Excellent performance in extreme conditions

Higher discharge capabilities of 80%–100%

Life span up to 20 years or longer

Low maintenance

Cons:

Its toxic components make it harmful to the environment

Lower stored power retention than other battery types

Not available for residential solar systems

These rechargeable batteries have a lower energy density, making them heavy and bulky, it also costs more than lead-acid batteries but less than the lithium-ion.

Best For: Large-scale solar installations and commercial projects.

Flow Batteries

Flow batteries tap the potential of liquid electrolyte chemistry to offer scalable solar storage. Two solutions flow between tanks, fueling chemical reactions during charge and discharge. Adding tanks multiplies capacity linearly - ideal for large facilities.

This design facilitates complete cycling with minimal waste. However, tank sizing and weight presently constrain energy density. Significant real estate is also required as tanks multiply.

Frequent electrolyte maintenance presents operational challenges. But a 20+ year lifespan rewards upkeep. Enviro risks are non-existent too, since chemistries stay benign. Cost currently limits residential viability.

Pros:

Ability to add tanks makes storage capacity customizable

Excellent efficiency and life span of 20 years or longer

Nontoxic and nonflammable components for improved safety

Cons:

Too expensive for residential use

Low power density due to internal tanks’ size and weight

High-maintenance

Best For: Large-scale installations. There is currently no residential version available at an affordable price.

Tips for Choosing Solar Battery Types

Batteries are truly the heartbeat of any solar power system. To maximize efficiency and lifespan, careful consideration is key.

Lithium-ion and lead-acid batteries remain popular for homes, RVs and more. By weighing your unique needs like space, budget and climate, the optimal chemistry emerges.Factors like cycle life, backup time required and desired service years must inform the decision. Lithium often excels for compact arrays or mobility.

Evaluate each option's cycling abilities and look for a reputable brand with a strong performance warranty, all of the OUPES power stations use LiFePO4 batteries and come with a 36-month warranty, ensuring peace of mind.

Following a thoughtful selection process will lead you to a solar battery optimized for your application and budget. One empowering energy independence through efficient, durable service for years to come.

Regardless of chemistry, the best choice energizes your specific goals. With due diligence, you're sure to find a solar champion powering adventures for sun seasons to come.

Two Major Types of Solar Charge Controller

We mentioned earlier what a solar charge controller works for: balance the voltage from solar panels array, and how to calculate the required size of it. Now let's talk about the types of solar charge controllers and how they differ.

The two major types of solar charge controllers are: Pulse Width Modulation (PWM) controllers & Maximum Power Point Tracking (MPPT) controllers.

PWM controllers

PWM regulation strategically meters solar voltage to batteries at fixed conversion rates. Ideal for smaller, simpler setups, these controllers offer low-cost, low-maintenance operation well-suited to entry-level systems.

However, their functionality is limited to fixed solar panel configurations, and they tend to be less efficient than their MPPT counterparts. It reduces their current output gradually as the battery charges. Once the battery reaches 100% charge, the controller can keep it full by providing small amounts of power without overcharging.

PWM solar charge controllers are designed to be used with solar panels that match the battery voltage. For example, if you want to charge a 12V battery, you also need photovoltaic modules with a rated output of 12 volts.

Pros:

More affordable than MPPT charge controllers

Smaller and easier to carry around

Suitable for DIY solar energy systems

Cons:

You cannot charge batteries with higher-voltage solar panels

Less efficient than MPPT charge controllers

Less efficient in cold weather

MPPT controllers

MPPT controllers are more efficient and versatile, better suited for larger and more complex solar systems. They can track the maximum power point of the solar panel, providing up to 30% more power than a PWM controller, and can work with any type of solar panel configuration.

However, their increased performance comes at a higher price point compared to PWM controllers. Despite the price, solar charge products with MPPT controllers are more popular on the market.

An MPPT charge controller can match a battery system with solar panels of higher voltage, keeping your solar panels at the ideal voltage and current for maximum power output. At the same time, the controller keeps a suitable charging voltage for the battery system.

As a quick example, assume a small solar array is operating at 36 volts and 10 amps, providing 360 watts of power. Using a PWM charge controller, you cannot use this power output to charge a 12V battery. However, an MPPT charge controller can lower the voltage to 12 Volts while increasing the current to 40 amps, which makes charging possible.

Pros:

You can charge batteries with solar panels of higher voltage

Up to 20% more efficient than PWM charge controllers

Can handle higher wattages efficiently

Cons:

MPPT technology is more expensive

Installation is more complex

Less efficient in systems smaller than 170W

Tips for Choosing PWM & MPPT

Whether selecting a PWM or MPPT charge controller, carefully match specifications to your particular solar panel and battery system. This ensures optimal and efficient performance for many years.

While MPPT controllers deliver the highest energy yields of up to 95%, PWM options remain a cost-effective choice for simpler applications. Consider if their slightly lower 70-80% efficiency still meets your needs.

Always confirm voltage and current ratings align between all components to avoid damage. An undersized controller leaves energy on the table, while an oversized one risks component harm.

Factor in efficiency gains from MPPT controllers that maximize solar harvesting versus PWM alternatives. The added cost may prove worthwhile for off-grid or battery-hungry loads.

Monitoring and temperature compensation features allow fine-tuning your system and extending battery life. An LCD display provides at-a-glance status checks too.

Research warranties, features, and reputable brands to find a quality controller tailored to your budget and application needs. With the right selection, your solar investment will power dependably.