Charge Controllers

A charge controller is used to keep the voltage across the battery within acceptable limits. The charge controller automatically tapers, stops, or diverts power when batteries become fully charged. Charge controller capacities range from 4 A to 100 A and multiple charge controllers can be used in parallel for larger systems. Some charge controllers offer additional features including charge status display, data logging, automatic battery equalization charging, generator starting, and even lighting controls.

The simplest charge controllers disconnect the power source when the battery reaches a set voltage, and turn it on when a low voltage set point is reached. Pulse Width Modulated (PWM) charge controllers turn on and off very rapidly, maintaining the batteries at full charge voltage, which results in quicker and more complete battery charging. Maximum Power Point Tracking (MPPT) charge controllers optimize the voltage of the PV array to maximize total power output then convert that to the correct voltage to charge the battery. This process significantly increases the power from a solar array, particularly in low temperatures when battery voltage is significantly below the PV array voltage. Most MPPT charge controllers work with higher array voltages, which can greatly reduce the required wire size between the array and the charge controller. While more expensive than PWM controllers, MPPT charge controllers can boost system performance by up to 30% making them very cost effective.

MPPT Charge Controllers

The table below shows recommended maximum nameplate PV array sizes. The wattages shown can be exceeded by up to 20% without damaging the controller, but some “clipping” of potential peak current may occur under cool, clear conditions at the peak of the day. While exceeding these wattages may reduce power harvest at peak times of the day, the total daily amp-hours delivered to the battery bank will be greater because the larger array will produce more power in less-than-peak conditions such as mornings, afternoons, and in hazy or cloudy weather.

MPPT Charge Controllers at a Glance



Max output currentMaximum recommended PV array sizeMax PV array voltage (V )





Item code

12 VDC24 VDC48 VDC
OutBack FLEXmax 6060 A750 W1,500 W3,000 W150 VDC020-02017
OutBack FLEXmax 8080 A1,000 W2,000 W4,000 W150 VDC020-02020
OutBack FLEXmax Ultra FM100100 A3,000 W6,000 W300 VDC020-02031
MidNite Classic 150 Or Classic SL96 A at 12 VDC


94 A at 24 VDC

86 A at 48 VDC



1,350 W



2,700 W



5,000 W



150 VDC




MidNite Classic 200 Or Classic SL79 A at 12 VDC


78 A at 24 VDC

76 A at 48 VDC



1,100 W



2,200 W



4,500 W



200 VDC




MidNite Classic 250 Or Classic SL61 A at 12 VDC


62 A at 24 VDC

55 A at 48 VDC



900 W



1,800 W



3,200 W



250 VDC




MidNite KID30 A450 W900 W1,800 W150 VDC020-02400
Magnum PT-100100 A1,500 W3,000 W6,000 W200 VDC020-06371
Schneider XWMPPT60-15060 A875 W1,750 W3,500 W150 VDC020-08040
Schneider XWMPPT80-60080 A2,560 W4,800 W600 VDC020-08048
Morningstar TS-MPPT-3030 A440 W880 W1,760 W150 VDC02001116
Morningstar TS-MPPT-4545 A650 W1,300 W2,600 W150 VDC020-01109
Morningstar TS-MPPT-6060 A875 W1,750 W3,500 W150 VDC02001110
Morningstar TS-MPPT-60-60060 A1,750 W3,500 W600 VDC02001103
Blue Sky SB3000i30 A w / 36-cell input 22 A w / 60-cell input400 W


290 W

50 VDC020-03121
Blue Sky SB2512i-HV20 A w / 60-cell input264 W50 VDC020-03164
Blue Sky SB1524iX15/20 A at 12 VDC


15 A at 24 VDC

270 W w / 36 cell
200 W w / 60-72-cell
400 W w / 72-cell57 VDC02003118
Blue Sky SB3024iL30/40 A at 12 VDC


30 A at 24 VDC

540 W w / 36-cell
400 W w / 60-72-cell
900 W w / 72-cell57 VDC020-03158

PWM Charge Controllers

It is important to note that PWM charge controllers have limited voltage correction capabilities and should only be used with 36 or 72-cell modules (See Solar Modules) in series or parallel to match the battery voltage.

NOTE: The nominal PV array wattages listed assume 36-cell modules with an 18.0 VDC maximum power voltage (Vmp), installed in a location with nominal 1000 W per square meter solar irradiance.

Higher or lower rated module voltages, and high altitude or other locations which regularly see higher solar irradiance requires adjustment to the wattages shown. The wattages shown also include the derating to 80% required by the National Electric Code for PWM controllers (maximum rated output current times 0.8)





Max output currentNominal PV array size 


Item code

12 VDC24 VDC48 VDC
SmartHarvest SCCP10-05010 A120 W240 W020-02039
SmartHarvest SCCP05-0505 A60 W120 W020-02038
MidNite MNBRAT20 A charger w/10 A load control or 30 A charger360 W720 W020-02435
Schneider C-3535 A420 W840 W020-08004
Schneider C-4040 A480 W960 W1,920 W020-08005
Schneider C6060 A720 W1,440 W020-08040
Schneider C-1212 A144 W020-08048
Morningstar TS-4545 A540 W1,080 W2,160 W020-01105
Morningstar TS-6060 A720 W1,440 W2,880 W02001108
Morningstar PS-15


Morningstar PS-15M


15 A180 W360 W020-01120



Morningstar PS-15M-48


Morningstar PS-15M-48-PG

15 A720 W02001126



Morningstar PS-30


Morningstar PS-30M

Morningstar PS-30M-PG


30 A360 W720 W3,448 W02001132




Morningstar SS-6-12V


Morningstar SS-6L-12V

6 A72 W020-01245



Morningstar SS-10-12V


Morningstar SS-10L-12V

10 A120 W020-01230



Morningstar SS-10L-24V10 A240 W02001236
Morningstar SS-20L-12V20 A240 W020-01239
Morningstar SS-20L-24V20 A480 W020-01242
Morningstar SL-10-12V10 A120 W 020-01218
Morningstar SL-10-24V10 A240 W 020-01221
Morningstar SL-20-12V20 A240 W 020-01224
Morningstar SL-20-24V20 A480 W 020-01227
Morningstar SG-44.5 A75 W020-01215
Morningstar SK-66 A72 W020-01252
Morningstar SK-1212 A144 W020-01253
Morningstar SSD-25RM25 A300 W020-01250
Blue Sky SB2000E25 A300 W020-03122
Blue Sky SC30


Blue Sky SC30-LVD

30 A360 W020-03180



Atkinson PVLC-15


Atkinson PVLC-15MD

15 A180 W360 W020-05425




Atkinson PVLC-40


Atkinson PVLC-40MD

40 A480 W960 W020-05427