A solar charge controller or regulator is a device that regulates the volts and amps coming from the solar panel to safely charge the battery
So selecting the right size charge controller for solar panels is what makes some folks confused. Because the Charge controller capacity is measured in Amps (A). But the capacity of the solar panels is rated in watts
Or if you already have a charge controller and thinking about adding some more solar panels or about buying a charge controller for your solar panels
Whatever the reason is you have come to the right place, with the help of bellow given charts you can figure out how many watts a charge controller can handle
Note! Read the part where I have described " how many solar panels a charge controller can handle " to keep your solar panel system safe
How to calculate the charge controller watt limit?
To calculate how many watts a charge controller can handle use this formula
Charge controller watt limit = Charge controller capacity (A)*Charge controller input volts (v)
Every capacity charge controller has an input volt mentioned, Some of them will just only accept 12v solar panels or some other ones can handle up to 48 volts
Like this my Renogy 20A MPPT charge controller, it can handle up to 20 amps on 12 and 24-volt solar panel system
For example
Let's assume that you have a 20A charge controller in a 12v solar panel system
20A*12v = 240 watts
20A charge controller in a 12v solar panel system
20*24 = 480 watts
How many watts can a 20 amp charge controller handle? 20 amp charge controller can maximum handle 240 watts in a 12v solar panel system and 480 watts in a 24-volt solar panel system
How Many Watts Can Any size Charge Controller Handle? Chart
Use this chart to figure out how many watts any sized charge controller can handle in 12v, 24v, & 48v solar panels system
| Charge controller size (Amp) | How many watts can handle @12v | How many watts can handle @24v | How many watts can handle @48v |
|---|---|---|---|
| 5 amp | 60 watts | 120 watts | 240 watts |
| 10 amp | 120 watts | 240 watts | 480 watts |
| 15 amp | 180 watts | 360 watts | 720 watts |
| 20 amp | 240 watts | 480 watts | 960 watts |
| 30 amp | 360 watts | 720 watts | 1440 watts |
| 40 amp | 480 watts | 960 watts | 1920 watts |
| 50 amp | 600 watts | 1200 watts | 2400 watts |
| 60 amp | 720 watts | 1440 watts | 2880 watts |
| 70 amp | 840 watts | 1680 watts | 3360 watts |
| 80 amp | 690 watts | 1920 watts | 3840 watts |
| 100 amp | 1200 watts | 2400 watts | 4800 watts |
Conclusion
- 10 amp charge controller can handle up to 120 watts in a 12v solar system
- 30 amp charge controller can handle up to 360 watts in a 12v solar system and 720 watts in a 24v system
- 40 amp charge controller can handle up to 480 watts in a 12v solar system and 960 watts in a 24v system
- 60 amp charge controller can handle up to 720 watts in a 12v solar system and 1440 watts in a 24v system
Note! if you're running DC appliances through the charge controller so make sure that the wattage of your appliance should not exceed the watt limit of the charge controller
Now let's discuss how many watt solar panels " actually " you can connect with the charge controller
How Many Solar Panels Can a Charge Controller Handle?
A 30A charge controller can handle a maximum of 360-watt solar panels in a 12v solar array and 720 watts of solar panels in a 24v solar array
to calculate the how many solar panels a charge controller can handle, you would need to figure out how many watts your charge controller can handle (with the help of above chart)
Important disclaimer!
These are the maximum watts your solar charge controller can handle but it's always safe to connect 20% less watts of solar panels (to cover up the fluctuations in solar panel's output)
Sometimes your solar panel will produce way more power than its actual watt rating (which will last a couple of seconds) but it's enough to cause any damage to your charge controller, solar panels, or even batteries.
For example:
360 - 20% or (360*0.8) = 288
You can " SAFELY " connect up to 280 watts of solar panels with a 30 amp charge controller in a 12v solar array
Chart - How Many Solar Panels Can Charge Controller Handle?
| Charge controller capacity | How many 12v solar panels (W) | How many 24v solar panels (W) |
|---|---|---|
| 10 amp | 96 watt | 192 watt |
| 15 amp | 144 watt | 288 watt |
| 20 amp | 192 watt | 384 watt |
| 30 amp | 288 watt | 576 watt |
| 40 amp | 384 watt | 768 watt |
| 50 amp | 480 watt | 960 watt |
| 60 amp | 576 watt | 1152 watt |
| 70 amp | 672 watt | 1344 watt |
| 80 amp | 552 watt | 1104 watt |
| 100 amp | 960 watt | 1920 watt |
Conclusion
- 20 amp charge controller can handle up to 12v 192 watts of solar panels (including, leaving an extra 20% watt capacity for safety reasons)
- 40 amp charge controller can handle up to 12v 384 watts of solar panels (including, leaving an extra 20% watt capacity for safety reasons)
- 60 amp charge controller can handle up to 12v 576 watts of solar panels (including, leaving an extra 20% watt capacity for safety reasons)
I hope this short guide was helpful to you, if you still have any queries don't hesitate to contact us or leave a comment below.
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