How Many Watts Can A 30 Amp Charge Controller Handle?
How many watts will a 30 amp charge controller handle?
Charge controller specification sheets don’t normally indicate a maximum power rating in watts. After all, this can easily be figured out using volts and amps, right?
It gets complicated when dealing with devices that can have more than one input voltage and output voltage.
The output charging volts can be set or variable depending on the controller, which allows 12V, 24V, 48V or higher voltage battery banks to be charged.
The first step is to consider which type of solar charge controller is to be used, MPPT or PWM.
Solar charge controller power rating in watts is determined by output current and output charging voltage. A 30 amp charge controller with nominal 12 volt output can handle 360 watts. The same charge controller charging a battery with 24V nominal voltage can handle 720 watts.
Video – Understanding Max Power of Victron Solar Charge Controllers
What’s the difference between MPPT and PWM charge controllers?
PWM (Pulse Width Modulation) charge controllers are the cheaper option and are definitely not as efficient as the more expensive MPPT (Maximum Power Point Tracking).
You can find a thorough explanation here, but basically MPPT controllers match the internal resiatnce of connected solar panels which creates the right conditions for maximum power conversion.
MPPT can be up to 40% more efficient than PWM controllers. (MPPT vs PWM tests.)
The other significant difference is the input voltages allowed for each type. A PWM charger generally has a much lower input voltage than MPPT (see tables later on in post).
Note: Typical open circuit volts (Voc) for a nominal 12 volt panel can be between 18 and 22 volts. the voltage reduces when in operation.
30 amp PWM charge controller typical specifications
PWM controllers operate in a basic way and are not very adaptable in terms of PV input.
If the battery charging profile calls for 30 amp charging current at 14 volts, then any extra power supplied by the solar panels will be simply wasted.
While there is some variation in PV input volts in the more expensive models, in general the input voltage level is much lower than MPPT.
TABLE 1 – Specifications for PWM charge controllers compared
Charge Controller 
Output current rating (DC amps) 
Nominal battery voltage (DC output) 
Recommended PV voltage (Voc input) 
Power rating (watts) 
Blue Sky Sun Charger 30 
30 (27 preferred) 
12 volts 
24 volts 
360 watts 
HQSTCTRLPWM30 
30 
12/24 volts (auto detect) 
55 volts max. 
360/720 watts 
Samlex Solar SCC30AB 
30 
12/24 volts (manual switch) 
50 volts max 
360/720 watts 
Coleman 30 Amp Digital 
30 
12 volts 
25 volts max. 
360 watts 
Xantrex Solar 30 Amp 
30 
12/24 volts (auto detect) 
50 volts max. 
360/720 watts 
Morningstar Prostar 
15/30 
12/24 (manual) 
60 volts max. 
180/360 watts 
Renogy Wanderer 
30 
12 volts 
25 volts 
360 watts 
30 amp MPPT charge controller typical specifications
MPPT controllers can be several times more expensive than PWM but they can provide up to 40% more charging energy.
They do this by tracking the maximum power point (MPP) of the solar panels input. Higher voltages are converted into current instead of wasted.
In general, much higher input voltages and output charging voltages are allowed, meaning a 30 amp MPPT charge can handle more watts.
TABLE 2 – Specifications for MPPT charge controllers compared
Charge Controller 
Output current rating (DC amps) 
Nominal battery voltage (DC output) 
Recommended PV voltage (Voc input) 
Power rating (watts) 
Midnite Solar – The Kid 
30 
12 to 48 volts 
150 volts max 
360 to 1440 watts 
Jaboni 30AMPPTRVC 
30 
12 volts 
45 volts max. 
550 watts 
Morningstar TSMPPT30 
30 
12/24/48 volts 
150 volts max 
400/800/1600 watts 
AIMS 30 AMP MPPT 
30 
12/24 volts 
100 volts max. 
400/800 watts 
Microcare LED MPPT 30 
30 
12/24 volts (auto detect) 
50 volts max. 
360/720 watts 
Renogy Rover 
30 
12/24 (auto) 
60 volts max. 
780 watts 
How many watts can a 60 amp charge controller handle
Charge controller watts depends on the output charging voltage. For a 12 volt charging system, the power in watts would be:
60 amps x 12 volts = 720 watts
If charging a 24 volt battery bank at 60 amps, then the power calculation is:
60 amps x 24 volts = 1440 watts
MPPT controllers are often able to handle more power, as they operate in a completely different way.
How many watts can a 50 amp charge controller handle
In general, charging volts for higher amp charge controllers can be selected between 12 or 24 volts. In each case the power handled would be different.
If charging at 50 amps for a 12 volt battery bank:
50 amps x 12 volts = 600 watts
When recharging a 24 volt battery bank at 50 amps, it would be:
50 amps x 24 volts = 1200 watts
How many watts can a 100 amp charge controller handle
As the current rating of solar chargers get higher, the output charging voltage increases, particularly with MPPT technology.
A good quality MPPT charge controller may have output settings of 12, 24, 36 and 48 volts. In each case the power being handled would be different:
100 amps x 12 volts = 1200 watts
100 amps x 24 volts = 2400 watts
100 amps x 36 volts = 3600 watts
100 amps x 48 volts = 4800 watts
How many watts can a 20 amp charge controller handle
Lower current devices generally specify one PV voltage input of 12 volt nominal (22V Voc) and one output charge voltage of 12V.
20 amps x 12 volts = 240 watts
How many watts can a 40 amp charge controller handle
MPPT or PWM 40 amp charge controllers may or may not have variable input PV and battery charging output volts, but let’s assume 2 possible output voltages of 12 and 24 volts:
40 amps x 12 volts = 480 watts
40 amps x 24 volts = 960 watts
How long will a 100ah battery run an appliance?
The table below gives runtime estimates in hours for a 100Ah leisure (deepcycle) battery running various DC and AC loads.
Runtime for AC loads is slightly less than DC because an inverter needs to be used, which have an efficiency of about 95%.
Hours Run Time 12 volts 100Ah deepcycle leadacid battery (50%DoD) 

Load in watts

Run time in hours 

DC Load 
AC Load 

20 
30 
28.5 
40 
15 
14.25 
100 
6 
5.7 
300 
2 
1.9 
500 
1.2 
1.14 
600 
1 
0.95 
1000 
0.6 
0.57 
1500 
0.45 
0.427 
3000 
0.2 
0.19 
How many solar panels does it take to charge a 100ah battery?
It all depends on the state of charge of the battery. I’m assuming that it’s a leadacid battery and it isn’t discharged 100%.
The table below shows how many solar watts would be needed to recharge a 100Ah auto battery with DoD (Depth of Discharge) 20% and also a 100Ah deepcycle battery with DoD 50%.
As solar panel output is very dependent on irradiation, I show how the solar power needs to be adjusted depending on geographic location.
Location 
Glasgow, UK 
Chicago, Il 
Lancaster, Ca 

Peaksunhours/day 
1.86 
4.03 
8.07 

Solar panel rating in watts needed to fully charge each battery type in one day – full capacity 100Ah 
Car Battery – 20Ah discharged (20%) – 240 Wh required 
130 watts solar panel rating required 
60 watts solar panel rating required 
30 watts solar panel rating required 
Deepcycle – 50Ah discharged (50%) – 600Wh required 
322 watts solar panel rating rerquired 
149 watts solar panel rating required 
75 watts solar panel rating required 
Charge controller specifications and PDFs:
PWM 30A solar charge controllers
Blue Sky Energy Sun Charger SC30
Samlex 30 Amp Solar Charge ControllerSCC30AB
MPPT 30 amp solar charge controllers
Renogy Rover