Last Updated on December 31, 2020
When we think of solar energy, the first and pretty much only things that come to mind are solar panels.
We know that they soak up lots of lovely free energy from the sun so we can power our appliances in a totally green and self-sufficient manner.
What we don’t normally think about is the complex process that connects all that free sun juice to the things we need to power.
One of the most important parts of this system is the MPPT charge controller.
Without an MPPT, you’re committing two cardinal solar sins.
Firstly, any battery you wish to charge with your solar setup is at risk of overcharging which will drastically reduce the lifespan of the battery or will destroy it in a matter of hours.
Secondly, you’re wasting tons of that precious power you’ve worked so hard to harness, but fret not, sun siphoners.
We’re going to be reviewing five of the very best MPPT charge controllers on the market at the minute so you can savor that sunny goodness and power on through the approaching winter.
Next, we’ll run through an in-depth buyer’s guide, cluing you up on all things MPPT, then we’ll round things up with a brief FAQ segment to cool all those burning questions.
No worries. Here’s our top pick right away.
Giving your sun suckers a helping hand at our number one spot is a charge controller kitted out with all you need for energized and healthy batteries.
Even if you’re a custodian to a veritable battery graveyard at this point, the Victron MPPT can bring your wasted cells back from the dead. As long as a battery isn’t completely sulfated or otherwise damaged, this intelligent device can reanimate it from 0 volts.
This MPPT is all about efficient tracking backed by cutting edge technology. There shouldn’t be a moment that your solar energy isn’t fully measured and appropriately designated, meaning basically zero waste.
One of the features we really love about this unit is the intelligent load output that stops any connected battery from ever falling truly flat. This is going to add some valuable battery life and save you plenty of money in the long run.
Thanks to the built-in Bluetooth technology, the eco war you’re fighting needn’t be as strenuous physically as it is mentally. Relax, put your feet up, and monitor and control this MPPT remotely using your smartphone and the VictronConnect app.
It’s a little expensive compared to some other MPPT controllers available at the minute, but we feel the assurance and convenience it provides is worth every single dime.
- Can operate with batteries as low as 0 volts
- Connect to it via Bluetooth to monitor and control remotely
- Cutting-edge technology provides near-constant energy tracking
- Intelligent load output prevents batteries from ever going flat
- Reduces solar waste significantly
- It’s a little pricey
Squeezing your sun-soaked panels like a wet sponge at our number two spot is another amazing MPPT charge controller that never takes its electrical eye off your solar panel’s bounty.
The advanced MPPT technology of this Epever unit equates to 99.5% tracking efficiency, and the more accurately a charge controller monitors power, the better it can handle and distribute it.
In this case, you’re looking at a 98% peak conversion rate, so no more wasted sunbeams, hurray!
Batteries need love too, and this Epever mediator knows this, which is why it protects against overcharges from the panels and over-discharging in the event of an overload or short circuit.
Moreover, it offers temperature compensation and four stages of charging potential: bulk, boost, float, and equalization.
It doesn’t have the fantastic Bluetooth connectivity of our first pick, but it does come with a neat little remote meter with a backlit LCD display. Simply mount it in a location of your choosing and it’ll provide constant insight into the functioning of your own little solar system.
- Protects against reverse polarity, overcharging, over-discharging, overload, short-circuiting, and reverse current
- Comes with remote meter with backlit LCD display
- Four-stage charging potential
- Incredibly efficient tracking
- Very high peak conversion rate
- Average conversion rate will be much lower than 98% peak
Scything the solar harvest in the sunny plains of our number three spot is an incredibly versatile controller perfect for those who have larger or more solar panels than the average setup.
First of all, let’s discuss this amazing range. You can use this MPPT in conjunction with solar panels with outputs between 12 and 48 volts. That’s pretty amazing considering our top two picks max out at 24V.
It’s a minimal difference, but with 99.73% tracking efficiency, this controller is even more efficient than our number two pick because it reassesses your solar panel’s status literally every second of every day.
Ultimately, more power accounted for means more power utilized.
Unfortunately, this unit doesn’t come with any form of remote monitoring (why it didn’t make our number two spot) which is a little disappointing as otherwise, this is a great charge controller.
That’s not to say it isn’t communicative enough though. The onboard backlit LCD display provides you with real-time energy statistics, load control modes, and daily and current power curves.
You can also expect full protection from overloading, overcharging, over-discharge, short-circuiting, and reverse polarity. In addition, it has great temperature compensation capabilities.
It might be of note to you that this is a Chinese made unit, which isn’t bad in itself, but the instruction manual is written in Chinese, so if this is your first MPPT, it might not be the one for you.
- Supports a wide range of generator sizes
- Backlit LCD display gives you constant updates in many forms
- Protects against discharges, overcharges, over-discharges, reverse polarity, overloads, and short-circuiting
- It has temperature compensation capabilities
- Incredibly high tracking efficiency
- Max conversion rate above 98%
- No remote monitoring
- Chinese manual
- Average conversion rate not specified
Coming in at number three is another powerful charge controller compatible with large capacity solar panels, making it perfect for those with more demanding energy uses.
It’s a very similar controller to our third pick. It has the very clear backlit LCD display that keeps you informed of operating data, working conditions, and load controls – all you need to know to feel comfortable your sun-drenched system is running smoothly.
Again, much like our number three option, it doesn’t come with any kind of remote monitoring device, so you’ll have to visit it once every so often to keep tabs on everything.
Thankfully, it comes with all the same protections as our other picks, and it supports three battery types: sealed, gel, flooded, and user-defined. Keep in mind there aren’t any automatic charging stages, so you’ll have to use the user-defined section for those kinds of charges.
The tracking efficiency and max conversion rates are given as beyond 99% and above 98% respectively. It may be slightly higher or lower performing than our other picks, we don’t know. Realistically, though, you probably won’t notice the minuscule difference either way.
A few customers have encountered little glitches in the firmware of these Onesolar charge controllers, but it was nothing that a quick reboot couldn’t fix, and hopefully will be addressed in the preceding firmware update.
- Backlit LCD display keeps you in the know
- Protects against all kinds of damaging surges
- Comes with three automatic charging functions and a user-defined option
- Solid tracking efficiency and conversion rate
- Compatible with a wide array of solar panels
- Fairly affordable
- Some experience firmware issues
- No remote monitoring
- Fewer automatic functions than some other picks
Our final charge controller for optimizing your sun snatchers is another Epever unit with an impressive PV rating.
It comes with the same fantastic remote monitor as its contemporary in our second spot, which is great, but if you want to be able to monitor processes on the unit itself, you’re out of luck.
For some reason, Epever chose not to include an onboard display. You can still monitor the basics using the illustrations and lights on the front panel, but that’s it.
Being that this is the second priciest controller on our list, it comes with a few neat features that the cheaper options don’t. For instance, although it’s only a 12V/24V unit, thanks to the impressive 150V max PV, it can hook up to more solar panels than usual.
The serial connection of PV modules also reduces excess current during the charging process, conserving energy for other applications.
Beyond that, you can expect all the usual battery protection with this unit, a similar conversion rate and tracking efficiency, and the same four charging options as our number four spot: flooded, sealed, gel, and custom.
- 150V PV allows it to control a longer series of panels
- PV modules slightly reduce current during a charge
- Protects your batteries from faults
- High tracking efficiency and conversion rate
- Remote monitor included
- No on-unit display
- No automatic bulk charging option
Best MPPT Charge Controller Buyer’s Guide
Before you push the button and purchase your new solar charge controller, here are some things you may want to consider.
It doesn’t hurt to come up with a rough budget, but keep in mind, the better your charge controller is, the more efficient your energy usage will be, saving you money over time.
Solar panels each have their own output, so you’ll need to find a charge controller that is powerful enough to receive it.
Most controllers will state a range of volts that they can receive. This could be 12 – 24V or even 12 – 48V. As long your panel’s output is listed, it should be compatible with the controller.
To be extra sure about compatibility when it comes to full solar panel arrays, you’ll need to find out the open circuit voltage of your system.
Open circuit voltage, also known as VOC, refers to the maximum voltage output of your panels under a load, and it can be measured with a voltmeter.
As long as the VOC is below the solar charge controller’s capacity, even if there are multiple panels, everything will work, and nothing will get damaged.
Controllers like our first two picks with PVs between 50 – 100V are perfect for small to mid-sized panel networks. If you’ve got a fairly expansive solar setup, you’ll probably be looking for 150V PV controllers like our last three picks.
No matter how you’re powering an appliance(s), you need to know how much electricity is required to do so.
If your solar array doesn’t cover all the things you want it to as of yet, and you plan to expand, it’s best to future-proof your controller in preparation.
Look for something that can handle your current situation as well as your expansion plans.
The beauty of MPPT controllers is that they’re programmable, allowing you to charge any battery with precision, but it’s also nice to have some automatic options for really quick, hassle-free usage with some standard battery capacities.
Typically, you’ll find controllers with a four-stage preset, but they’re not always the same.
To find the best controller for you, think about what kind of charges you require and look for one that has them pre-loaded in its system.
Bulk – Bulk charging throws as many amps into a battery as fast as possible until it hits a certain amount when it will switch into absorption charging. This is perfect for charging large capacity batteries quickly.
Absorption – Absorption is the next phase of the charge. It’s a longer, more delicate process.
Float – Float is the next phase. It’s even more gentle than absorption, filling the last small remnants of space in the battery.
Boost – Boost is similar to bulk, but it’s used primarily to drive a battery with an exceedingly low charge back into action, before settling back down to a softer charge.
Equalization – Equalization refers to a charging method that deliberately overcharges a battery. This is part of routine maintenance for lead acid batteries as the overcharge removes sulfate crystals from the battery’s plates.
Extra Features – What Will Make Things Easier for You?
As you’ve seen from our list, despite their largely similar functions, MPPT solar controllers can have a wealth of different features.
LCD Display – LCD displays are easy to read and can offer loads of different information at the same time.
Remote Monitoring – A controller that comes with some form of remote monitoring is going to be far more practical, but will probably carry a higher price tag. Some controllers will come with a separate monitor, others can be observed from your computer, or from your smartphone via Bluetooth.
Manual Load Control – This function stops a battery’s output before it’s completely depleted, thereby elongating its life.
Temperature Compensation – This function simply uses a temperature sensor to assess what kind of charging is appropriate for the battery at a given moment.
Solar charge controllers aren’t perfect devices.
We recommend looking for one with a warranty between 3 months and a year.
Frequently Asked Questions
What’s better MPPT or PWM?
MPPT is considered by far the better option as it’s more efficient and gives you more control of the charging of your batteries.
That said, MPPT controllers are more complicated to use and set up. If you have a very small solar outfit, a PWM may suit you best.
Do solar panels drain batteries at night?
The short answer is, no.
There may be a minimal discharge, but it will never be anywhere close to the loss of a full charge.
How many watts can a 40-amp solar charge controller take?
It depends on the voltage of the load. For instance, a 40-amp controller running with 12V panels can handle 520 watts.
The same controller running with 24V panels will handle 1040 watts.
There you have it, sun savers. Five of the very best solar charge controllers for making the most of your solar panel array, keeping your life green and electric.
If you do settle for one of our listed products, we know you won’t regret it. Each of them is great in their own right. But if you didn’t find anything on our list for you, don’t worry.
We found tons of other great products when we were narrowing down our list. It’s a shame we couldn’t show you more.