# Combining MPPT and Non-MPPT Charge Controllers

Posts: 16Registered Users
Is there any harm to connecting either in series or parallel one 30 Amp MPPT Charge Controller with one 30 Amp Non-MPPT Charge Controller other than cancelling out the MPPT function altogether? Array size is simply (2) 120 watt panels with the following specs:
Open-Circuit Voltage (Voc): 22.0V
Short-Circuit Voltage (Isc): 7.37A
Voltage at Pmax (Vmp): 17.5V
Current at Pmax (Imp): 6.86A
Output Tolerance: +/-3%
For controller parallel connections, would voltage and wattage capability double? i.e., 24 volts to 48 volts and 720W to 1440W
For controller series connections, would amperage capability double to 60 Amps?

Any feedback is much appreciated.

• Posts: 17,615Banned ✭✭
Re: Combining MPPT and Non-MPPT Charge Controllers

PWM and MPPT controllers can work fine together.

I've got to ask why you wonder, as two 120 Watt panels will only put out <15 Amps and you don't put two controllers on one array. There is no point to it.
You also do not connect controllers in series.

But you can use two different type controllers each with its own array to charge one battery bank.
• Posts: 16Registered Users
Re: Combining MPPT and Non-MPPT Charge Controllers

If they work fine together, can a 30A MPPT charge controller be connected in parallel to a 30A PWM Charge Controller if I were to add panels to the array to achieve maximum wattage 1.4kw and between 48-60 amps?
• Posts: 17,615Banned ✭✭
Re: Combining MPPT and Non-MPPT Charge Controllers
If they work fine together, can a 30A MPPT charge controller be connected in parallel to a 30A PWM Charge Controller if I were to add panels to the array to achieve maximum wattage 1.4kw and between 48-60 amps?

Yes, but you have to split the array between the two controllers.
On a 12 Volt system this would not be 1400 Watts total. One 30 Amp PWM or MPPT controller could handle four of the panels you list (6.86 Imp * 4 = 27.44 Amps). That would be 360 Watts per controller for a total of 720 Watts.
On a 24 Volt system this would be double the panels as you would first connect two in series to get the Voltage up to the proper level for charging; the current remains the same. Total power doubles.
• Posts: 16Registered Users
Re: Combining MPPT and Non-MPPT Charge Controllers

Now I see the advantage to bypassing 30 or 60 amp MPPT or PWM charge controllers and backfeeding into the grid with an inverter, it does not make sense to increase panel array voltage and amperage if there is very little room to store a 24 or 48 volt battery assembly. Thanks for your feedback.
• Posts: 17,615Banned ✭✭
Re: Combining MPPT and Non-MPPT Charge Controllers
Now I see the advantage to bypassing 30 or 60 amp MPPT or PWM charge controllers and backfeeding into the grid with an inverter, it does not make sense to increase panel array voltage and amperage if there is very little room to store a 24 or 48 volt battery assembly. Thanks for your feedback.

You're talking about a completely different scenario there: grid tie vs. off grid.
You can store tremendous amounts of power in a battery bank, but everything has to be sized properly.
• Posts: 3,009Solar Expert ✭✭✭✭
Re: Combining MPPT and Non-MPPT Charge Controllers
Now I see the advantage to bypassing 30 or 60 amp MPPT or PWM charge controllers and backfeeding into the grid with an inverter, it does not make sense to increase panel array voltage and amperage if there is very little room to store a 24 or 48 volt battery assembly. Thanks for your feedback.
Sorry, i cannot grasp the meaning of, or understand this post - - - -
Are you saying that you think it would be better to go with a grid-tied system rather than a stand alone off grid system?