Knowing the maximum volt limit of any change controller will determine how many watts of solar panels you can connect with it safely.
if you currently have an 80A charge controller or are about to buy one and are curious about how watts it can handle so stay with I’ll explain it in a simple way and will share a formula to calculate the watt limit of any charge controller
30 amp charge controller with nominal 12 voltage can handle 960 watts, with 24-volt nominal it can handle 1920 watts and 3840 watts with 48-volt nominal. We calculate the watt limit of any charge controller by multiplying the amps (Charge controller) with Volts (battery)
It’s not recommended to use a charge controller at its full capacity always leave the 20% for safety factors which I’ll share later on.
Now let’s discuss how to calculate the watt limit of any charge controller by using some examples and later on I’ll share some tips on using a charge controller
Video – Explaining basics of solar charge controller
How to figure out watt limit of charge controller?
To calculate the watt limit of 80a charge controller we use this formula Multiply the Amps of a charge controller with nominal voltage = maximum watt a charge controller can handle
e.g if you have 12v solar panels connected in parallel the total output voltage will be 12v
30 x 12 = 960 watt
if you have the same solar size with 24 nominal it would be
30 x 26 = 1920 watts
You get the idea, so this is how you can calculate the watt limit of any charge controller.
These numbers will fluctuate a little bit because we know that if you have a 12v battery it can absorb about 14v and 12 solar panels will produce about 18 volts under ideal sunlight conditions. so in this case, the voltage will increase up to 14 also the watt limit of the charge controller
a little tip here if you’re using a PWM charge controller it will draw down the voltage of solar panels to 14v to match the battery voltage but the amps will stay the same. which will cause a power loss. so I always recommend using an MPPT charge controller which will decrease the voltage and will increase the amps so at the end you’ll get the maximum power from the solar panels
Do not use your charge controller at it’s full capacity
previously we have calculated the maximum watt an 80 amp charge controller can handle in different voltage nominal, but the experts recommend not using a charge controller at its full capacity because it can damage the batteries or charge controller in case of any fluctuation in the voltage from the solar panels.
you should use 80% of what a charge controller can handle which will keep the solar system safe.
690 – 20% = 550 watts
so it’s better to connect a 550-600w solar panel in a 12-volt connection with an 80 amp charge controller. You can now further calculate the value according to your solar array voltage
Charge controller output DC volt
DC output volt of any charge controller determines its overall power output. for example, a 12v output charge controller can handle less watt than a 24v output charge controller.
some 80 amp charge controllers can handle a 12v system and some can handle up to 48 volts. so a charge controller which can handle 48 volts of solar array can also handle more watts.
because of this formula volts x amps = watts
as the voltage will increase the charge controller would be able to handle more watts. so make sure to check a charge controller before buying how many volts it can handle
Here are some examples of 80A charge controllers with volt capacity
| Charge controller | Nominal Volts | Watt limit |
| AMPINVT 80 amp MPPT | 12/24/34/48v | 960/1920/2880/3840 watts |
| Outback Power 80A MPPT | 12/24/48v | 960/1920/3840 watts |
| EPEVER 80A MPPT | 12/24/36/48v | 960/1920/2880/3840 watts |
| PowMr 80A PWM | 12/24/36/48v | 960/1920/2880/3840 watts |
What size Solar panels for 80A chareg controller
as we have discussed the maximum watt limit of 80 amp charge controller now it’s easy to find out the right solar panels size for 80a charge controller.
80 amp charge controller can handle 960 watts in 12v solar array so you can connect 9.5 100w solar panels in parallel to charge a 12v battery with 80A charge controller or 6.4 24v 300w solar panels in parallel you get the idea. Divide the maximum DC output of the charge controller according to a voltage by solar panel watts
I have discussed in detail about should you connect your solar panels in parallel or series Read More…
Understanding max power of charge controller – Video
Conclusion
a charge controller is one of the most underrated important in the solar array which will determine the power output of solar panels into the battery and will keep the batteries safe and will increase their lifespan.
So choosing the right size charge controller for your solar array is very important. if you have an 80A charge controller now you know what it can handle and how many watts of solar panels you can attach to it.
I hope you’ve gained some knowledge from this post, ThankYou!
