5 Best Cheap PWM Solar Charge Controllers

I spent weeks testing 5 of the best PWM solar charge controllers available. After wiring them to custom-built solar power systems, assessing their user-friendliness, and researching their safety features and battery compatibility, I think the Renogy Wanderer 30A is the best PWM charge controller for most people.

The Wanderer 30A is designed for 12 volt batteries and can handle up to 400 watts of solar. That’s a good amount of power for most small-scale solar projects, such as those used in small vehicles and buildings. With that much solar you can power lights and some small devices and appliances — like phones, laptops, and maybe even a small 12 volt fridge.

Top Pick

Renogy Wanderer 30A

The best PWM charge controller

The Wanderer 30A is my favorite PWM controller because of its blend of build quality, ease of use, and value. It’s ideal for 12 volt batteries and can handle up to 400 watts of solar.

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The Wanderer 30A is easy to use and has plenty of built-in safety features, such as overcharging protection, to protect your system and maximize your battery’s lifespan.

It also has a place to add a battery temperature sensor for improved temperature compensation. Many PWM charge controllers don’t have a temperature sensor port, and it’s important if your batteries experience wide temperature swings.

The LED indicators are easy to understand and useful for monitoring your system at a glance. They’re all you need for set-it-and-forget-it systems. But if you want to see exact specs like charging current and battery voltage, you can purchase the Renogy BT-1 Bluetooth Module to monitor your system from your phone.

All Renogy PWM charge controllers I tested, including the Wanderer 30A, are compatible with sealed, gel, flooded, and lithium batteries. That’s another great thing about this controller — most other PWMs work with only lead acid batteries.

The Wanderer 30A is also one of the cheaper 30-amp PWM charge controllers available. Overall, it’s a great value.

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Budget Pick

Renogy Wanderer 10A

The best cheap PWM charge controller

The Wanderer 10A is an excellent budget option for smaller solar systems. It’s compatible with 12 and 24 volt batteries and has an LCD display for easy monitoring.

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The Wanderer 10A is a great cheap charge controller for lower-wattage 12 or 24 volt systems. For 12 volt systems, it can handle up to 130 watts of solar. For 24 volt systems, Renogy recommends a maximum of 260 watts.

That’s enough power to run some lights and charge your phone and laptop. For instance, I paired this controller with a 20 watt solar panel to solar power some LED lights in my dad’s shed. It was the perfect size for the project.

You could also use it to solar charge 12 and 24 volt batteries. It’ll treat your batteries better than most other cheap charge controllers, which tend to be low-quality.

There are a couple other features worth mentioning: Its LCD display makes it easy to see if everything is working properly. You can also use its 2 USB ports for charging phones and other USB devices.

In the sea of cheaply made charge controllers, the Wanderer 10A stands out as a top option.

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Honorable Mention

Morningstar SunSaver

A PWM charge controller that’s built to last

The SunSaver line has excellent build quality and is backed by a 5-year warranty. It has some of the best out-of-the-box battery protections to help maximize your battery’s lifespan. It’s expensive, though, and limited to sealed or flooded lead acid batteries.

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The Morningstar SunSaver is the buy-it-for-life option. It’s expensive, but it’s built to last and comes with a 5-year warranty.

Cheaper controllers cut costs by using plastic cases and screws that are all too easy to strip. The SunSaver, on the other hand, sports marine-grade terminals and an anodized aluminum case. It feels like you could drop it off a building with little consequence.

It has a built-in temperature sensor and, according to Morningstar, good voltage accuracy. There are also models available with low voltage disconnect (LVD). This means it has some of the best out-of-the-box battery protections.

It’s pricey, and only works with sealed or flooded lead acid batteries. If it’s right for your system, though, this controller may pay for itself by maximizing your battery’s lifespan.

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Best PWM Solar Charge Controllers

• Top Pick: Renogy Wanderer 30A
• Budget Pick: Renogy Wanderer 10A
• Honorable Mention: Morningstar SunSaver
• Renogy Adventurer 30A
• Allpowers 20A Solar Charge Controller

Top Pick: Renogy Wanderer 30A

PWM charge controllers, with their low cost and limited current ratings, are best suited for small-scale solar projects of roughly 400 watts or less. For these sorts of applications, the Wanderer 30A is likely all you need.

It has a current rating of — you guessed it — 30 amps, which works out to around 400 watts of solar. That’s enough to power quite a bit, like lights, phones, laptops, and maybe even a small appliance.

It’s simple to mount and set up. Just connect the battery then the solar panel to their respective terminals. LED indicators let you know if everything is working properly. The manual has step-by-step setup instructions and a legend detailing what the various indicator lights mean.

For set-it-and-forget-it solar systems, I think the LEDs are all you need. For closer monitoring, you can buy the Renogy BT-1 Bluetooth Module to monitor your system from your phone. It’s convenient but by no means necessary.

Selecting your battery type is as simple as pressing the buttons a few times. You can choose between 4 types: sealed, flooded, gel, and lithium. Most other PWM controllers only work with lead acid batteries.

The Wanderer 30A is a good choice if your battery will experience wide temperature ranges — such as in a building or vehicle without air conditioning. Temperature affects a battery’s ideal voltage and charging current set points. But many budget PWM controllers don’t compensate for temperature. So on hot and cold days, they can overcharge or overdischarge your battery and shorten its lifespan.

However, with the Wanderer 30A, you can get the compatible battery temperature sensor. It gives a more accurate battery temperature reading, allowing the charge controller to provide better temperature compensation. It can help your battery last longer, saving you money in the long run.

I’d still consider using the Wanderer 30A with 100 watts of solar or less. It gives you the ability to add more solar panels if you want to expand your system later on. You could start with LED lights and add a WiFi router later, for instance. PWMs with lower current ratings are more limited.

It’s sized well for 12 volt solar systems of 400 watts or less. It’s easy to set up and a good value for the price. For most people, I think the Renogy Wanderer 30A is the best PWM solar charge controller for the job.

Full review: Renogy Wanderer

Budget Pick: Renogy Wanderer 10A

The 10-amp model in the Wanderer lineup is my pick for low-wattage solar systems. It has a current rating of 10 amps and is compatible with 12 and 24 volt batteries. It can handle about 130 watts of solar in 12 volt systems and 260 watts in 24 volt systems.

That’s enough energy for powering lights and charging small devices and batteries. For example, here’s a solar lighting system I built with mine:

It has an LCD display that tells you charging current, PV voltage, battery voltage, and other useful system specs. Like it’s big sibling, it’s compatible with the Renogy BT-1 Bluetooth Module for remote monitoring.

Cheap solar controllers can treat your battery poorly, so I checked the Wanderer 10A’s battery voltage reading against a multimeter. Turns out it’s pretty accurate.

Many budget controllers are usually off in their battery voltage readings by a tenth of a decimal place or so, which — depending on the direction of the error — can lead to slight chronic overcharging or overdischarging and reduce your battery’s lifespan.

The Wanderer 10A doesn’t have a temperature sensor port, so it can’t provide accurate temperature compensation. Because of this, I recommend using it with batteries that are placed indoors where they won’t get too hot or too cold. Or, at the very least, use it with a cheap battery whose lifespan you aren’t trying to maximize.

I’d caution against buying the Wanderer 10A if you plan to add more solar panels later on. Its current rating is limiting, so you might have to replace it with another charge controller when you do.

There are cheaper charge controllers with higher current ratings, but be warned — they’ve been known to make wrong or misleading claims. The quality of the Wanderer 10A is a step above those.

That’s not to say it — or any cheap PWM — is perfect. I’ve had issues with mine. Like I said, I used it to solar power some lights for my dad’s shed. Well, he accidentally left the lights on too long and drained the battery. The Wanderer 10A was unable to recharge the battery with such a low voltage, and reported a constant “PV over-voltage” error. Replacing the battery didn’t fix the problem, so I eventually had to replace the controller itself.

Cheap PWMs are cheap for a reason. They work but lack some of the protections of more expensive PWM and MPPT controllers. They leave less room for user error. If you decide to get one, take care when designing and building your solar setup.

Honorable Mention: Morningstar SunSaver

The SunSaver is built to last. It has an aluminum anodized enclosure and marine-grade terminals. It can work in incredibly hot and cold temperatures.

It feels like a brick. Compared to the plastic cases of the other controllers I tested, the SunSaver seems indestructible. It’s even backed by a 5-year warranty.

It has a built-in temperature sensor and, according to MorningStar, a voltage accuracy of +/- 25mV. Models with low voltage disconnect are also available.

These features give it some of the best out-of-the-box battery protections among PWM controllers. It may pay for itself by extending your battery’s lifespan.

It’s compatible with sealed or flooded lead acid batteries, and is available in 12 or 24 volt models. Current ratings range from 6 to 20 amps.

It’s pricey and has limited battery compatibility. (If you’re using lithium batteries, you’ll have to look elsewhere.) But for systems using lead acid batteries, the SunSaver is worth a look. Morningstar is known for making charge controllers that last.

Renogy Adventurer 30A

The Adventurer 30A combines the best of both Wanderer models in one.

Start with the 30 amp current rating and temperature sensor port of the Wanderer 30A. Combine that with the LCD display and 12/24V compatibility of the Wanderer 10A. Make sure it’s still Bluetooth compatible. Add a battery voltage sensor port. And don’t forget the Adventurer’s own party trick — flush mounting.

This combination of features means the Adventurer 30A is great for 12 volt systems of up to 400 watts and 24 volt systems of up to 800 watts. That’s almost a 1kW system — we’re starting to talk serious power. That’s enough power for some small vehicles and off-grid buildings.

Flush mounting means the Adventurer is well-suited for vans, campers, RVs, and anywhere else you want an aesthetically cleaner flush mount.

But if you don’t, it can also be surface mounted to the wall like any other charge controller. It comes with an included surface mount attachment that lets you decide.

Then there’s the battery voltage sensor (BVS) port. Adding a BVS helps the controller maximize battery life when your charge controller and battery are far apart. On longer wire runs, there can be a voltage discrepancy between the battery and controller terminals.

The downside is the Adventurer 30A is one of the pricier PWM models out there. The Wanderer 30A performs similarly and costs less. For most 12 volt systems, I’d go with the Wanderer 30A.

But if you want its blend of features — or a flush mounted controller — the Adventurer 30A is a good option.

Full review: Renogy Adventurer

Allpowers 20A Solar Charge Controller

Nearly all the cheap charge controllers on Amazon look identical to this one: a small blue and black box, similar graphics, similar labels. The misspelled “build-in timer.”

It’s not a coincidence. You’ve just stumbled upon the most popular design for cheap charge controllers.

And when I say cheap, I mean it. A quick search on Aliexpress for “solar charge controller” turns up one of these blue-and-black models for just $2 USD. Two dollars!

As you’d expect, the Allpowers 20A charge controller was the cheapest model I tested. It works fine, but — as you’d also expect — the quality is lacking.

I nearly stripped the screws when applying a normal amount of torque. The controller got warm to the touch with only 3-4 amps of current running through it. No other controller heated up as much as this one.

The model I bought has a claimed current rating of 20 amps. I’d be nervous to give it 10.

It does have an LCD display, though it doesn’t show charging current (I only knew because I’d installed an inline watt meter). This is a nitpick, but the screen is also quite fuzzy. You might think my photos of it are out of focus. That’s just what the screen looked like.

I checked the battery voltage accuracy against a multimeter, and it was off by about a tenth of a volt. That’s not great, but for the price it’s acceptable.

The user manual mine came with says the battery charging voltage has an error margin of ± 0.15 volts. That’s not great. Voltage discrepancies can cause the charge controller to chronically overcharge or overdischarge your battery, shortening its lifespan.

If you want a budget PWM, I’d recommend spending a few bucks more for the Renogy Wanderer 10A if you can afford it.

But there is a use case for these budget models. I’d reserve them for very low-wattage solar projects with cheap lead acid batteries. They should work fine if that’s what you’re using them for. Just understand that they can have little margin for user error. You’ll have to design and build your system well, otherwise they may not last long.

How to Choose the Best PWM Solar Charge Controller for Your System

Nominal Battery Voltage

Your charge controller’s nominal battery voltage should match the nominal voltage of your battery bank.

If you’re using a 12 volt battery, you need a solar charge controller compatible with 12 volt batteries. Got a 24 volt battery? Use a charge controller compatible with 24 volt batteries.

It ain’t rocket science. 😉

Some PWM charge controllers are compatible with 12 and 24 volt battery voltages, making them more versatile.

Charge Current Rating

Choose a charge controller with a current rating that is greater than the expected max charge current from controller to battery. You can damage a charge controller if you exceed this number. You’ll also want to make sure this number is below the battery’s maximum recommended charge current.

You charge controller’s charge current rating (in amps) is usually included in the product name. For example, the Renogy Wanderer 30A can charge a battery at up to 30 amps, and the Wanderer 10A can do up to 10 amps.

If you don’t see the current rating in the product name, at the very least it should be listed on the product page and in the instruction manual.

Once you know how much current (amperage) your charge controller can output, you need to use a solar panel, or build a solar array, that stays below this limit.

You find out how much current your panel can produce by looking at the specifications label. The label will list a short circuit current (Isc) in amps. Make sure the controller’s current rating is greater than the panel’s short circuit current. Add a small buffer to be safe.

If you have solar panels connected in parallel, add together all panel’s short circuit currents to get your array’s short circuit current. Add a small buffer, then use this number for your comparison.

Maximum PV Input Power: Some brands, such as Renogy, also list a maximum PV input in watts for their charge controllers. This is simply another way of helping you to stay below the controller’s current rating.

Battery Compatibility

Pick a charge controller that is compatible with your type of battery. All PWM models I tested are compatible with sealed and flooded lead acid batteries. Some models are also compatible with gel batteries.

The most versatile PWMs are also compatible with lithium batteries.

Operating Temperature Range

Choose a charge controller with an operating temperature range suited to the location you plan to put it. Some PWMs have narrow operating temperature ranges that could exclude them from being used in buildings or vehicles without air conditioning.

Example: Let’s say you live in Florida and want to solar power your workshop. Your workshop doesn’t have AC, so on hot summer days it can get up to 110°F (43°C) inside.

The maximum operating temperature for the Renogy Wanderer 10A and 30A models is 113°F (45°C). The temperature inside your shed will get close to this limit, so you may want to choose a charge controller with a higher maximum temperature.

Note: Batteries have their own temperature ranges. Consider these as well when designing your system.

Maximum PV Open Circuit Voltage (Voc)

The maximum open circuit voltage (Voc) of your solar panel(s) shouldn’t exceed the maximum PV voltage of your charge controller.

Use our solar panel maximum voltage calculator to calculate your maximum open circuit voltage. Then, make sure you pick a charge controller whose max PV voltage is greater than this number.

<25V: It’s rare to see PWMs with less than a 25V PV voltage limit. Models in this range are usually not designed for use with 12V solar panels.

25-30V: Models in this range can handle one 12V solar panel wired in series and are designed for use with 12V batteries. To add panels, you’ll need to wire them in parallel.

50-60V: Models in this range can handle one to two 12V solar panels wired in series and are usually designed for use with 12V and 24V batteries.

>60V: It’s rare to see PWMs with a PV voltage limit greater than 60V. Models in this range are usually designed to handle 3 or more 12V solar panels wired in series.

Maximum Wire Gauge

Many charge controllers list the maximum wire size compatible with their terminals. The max wire gauge often allows much more current than the controller’s current rating. This means you can over-gauge your wires for added safety if you want.

Some charge controller reviews pay close attention to the wire terminals as a proxy for quality. I generally found this to be true in my testing.

Additional Features

LCD displays: LCD screens make it easy to see important specs at a glance, such as charging current or PV voltage. The alternative is LED indicators that flash at different speeds and glow in different colors to convey system status.

Temperature compensation: As batteries get hot or cold, the charging current and voltage set points should be adjusted. Not doing so risks damaging the batteries. This feature, called temperature compensation, is important for batteries that experience wide temperature swings, such as those placed outside or in buildings or vehicles without air conditioning.

There are two ways that charge controllers provide temperature compensation:

1. Built-in temperature sensors
2. Temperature probes

Built-in temperature sensors are convenient, but can only monitor the ambient temperature near the charge controller. If your battery is far away or has heated up from working, its temperature could be quite different.

Temperature probes can be taped directly to the battery for a more accurate battery temperature reading.

Some cheap PWM charge controllers claim to have temperature compensation. However, unless they have a built-in temperature sensor or a port for attaching a temperature probe, they have no actual way of measuring temperature. They usually just assume a set temperature of 25°C (77°F), regardless of how hot or cold the battery gets.

Remote Bluetooth monitoring: Bluetooth monitoring lets you monitor and control your system from an app on your phone.

Bluetooth monitoring is common on more expensive MPPT charge controllers, but rare on cheaper PWM models. In fact, none of the 5 PWM models I tested have it built-in.

All the Renogy PWM charge controllers I tested come with an RS232 port. It’s used to connect the Renogy BT-1 Bluetooth Module. You can then sync the BT-1 to your phone via the Renogy DC Home app.

These sorts of apps let you monitor your system in real time. You can also adjust system parameters, such as which type of battery you’re using.

PWM vs. MPPT Charge Controllers

PWM charge controllers are cheaper, but less efficient at converting incoming solar energy to the right current and voltage parameters to safely charge the battery. The rule-of-thumb efficiency for PWM charge controllers is around 75%.

PWM models are often used for small-scale solar power systems where efficiency isn’t a top priority.

For instance, I recently installed solar power lights in my dad’s shed. He didn’t need to use them that often, meaning charge controller efficiency wasn’t an important consideration. Accordingly, I chose a PWM controller for the project.

MPPT charge controllers are much more efficient, around 95% or so. However, they are much more expensive.

MPPT controllers are best for solar systems where efficiency is important. They also have higher current and PV voltage ratings, making them better suited for larger systems of around 400-1000 watts.

An example where an MPPT could be ideal is on a van with limited roof space. Because of the limited space, you want to maximize the amount of solar energy you can pull from your panels. You decide to go with an MPPT for its conversion efficiency.

Full breakdown: PWM vs MPPT Charge Controllers