BKBenton
New Member
I have a fairly new solar system up and running using a BougeRv 100A MPPT charge controller (ASIN B0CPLNW9Z8) powering a 15KW LiFePO4 battery bank wired in a 2S6P 24VDC configuration. MPPT has a max 150V solar input that I’m getting close to.
I’m running two strings of through a solar combiner with diodes and breakers. Each string is rated at 1335 watts, 125.7 Voc (measured at ~109V at string input), 13.48 Isc, 3 integrated diodes per panel. 3 Panels/string are: URE FBM445M7G-BB 120 cell, 445W Mono-crystalline PV
Current combiner outputs into 4AWG Cu wire trunk at 2670W theoretical, ~124 Voc (measured ~107V). On a normal sunny day I’m seeing about 2000W at the charge controller. (It’s winter ;o). I drive a 6KW pure-sine wave inverter, and charge my plug in RAV4 Prime, and run my garage on this system. We have lots of cloudy days, especially in winter, and May/June months - and I have some Issues with shading. Thinking about optimizers for a few of the troubled (shady) areas.
Everything is going so well, I would like to add an additional string to offset clouds snd shading issues. That would take me to ~4005W theoretical, which exceeds my 100A MPPT controller 3000W max input. I believe I can add a 2nd identical BougeRV 100A MPPT controller and set it up to run in parallel. Wanted to confirm that I can wire the solar panel power inputs in parallel and connect to my single 4AWG cable trunk (pair - Windy nation welding cable) from the solar combiner.
The MPPT controller is good for 3000W @24V (each.) It has a parallel connection, port.
I’m just checking to see if this type of dual controller configuration can draw from a single combiner output, and if the parallel configuration setup is used to allow both controllers to sync MPPT activity. I don’t want to drag another large Cu cable trunk 90 feet from the 3rd string to a 2nd controller. The cable is expensive. I understand the 4AWG trunk is a bit overkill at about 25A today, and even ~37A if I add the 3rd string.
At 2000W my wiring is cool as can be. Using 8AWG Cu from panels to combiner with 8AWG MC-4 connectors. All exterior cable runs are in a watertight conduit with 8AWG ground. Using short 1/0 cable in battery bank and short 2/0 from battery bank to inverter. All cable is O2 free pure Cu.
4AWG from combiner to controller as mentioned, and very short 4AWG from controller to battery bank. This short run gets up yo about 80F under 90A load. Max amps will go down under parallel controller configuration.
Is there any special trick to wiring such a setup? What am I doing wrong?
Appreciate recommendations as this is my first Solar project.
Thanks.
I’m running two strings of through a solar combiner with diodes and breakers. Each string is rated at 1335 watts, 125.7 Voc (measured at ~109V at string input), 13.48 Isc, 3 integrated diodes per panel. 3 Panels/string are: URE FBM445M7G-BB 120 cell, 445W Mono-crystalline PV
Current combiner outputs into 4AWG Cu wire trunk at 2670W theoretical, ~124 Voc (measured ~107V). On a normal sunny day I’m seeing about 2000W at the charge controller. (It’s winter ;o). I drive a 6KW pure-sine wave inverter, and charge my plug in RAV4 Prime, and run my garage on this system. We have lots of cloudy days, especially in winter, and May/June months - and I have some Issues with shading. Thinking about optimizers for a few of the troubled (shady) areas.
Everything is going so well, I would like to add an additional string to offset clouds snd shading issues. That would take me to ~4005W theoretical, which exceeds my 100A MPPT controller 3000W max input. I believe I can add a 2nd identical BougeRV 100A MPPT controller and set it up to run in parallel. Wanted to confirm that I can wire the solar panel power inputs in parallel and connect to my single 4AWG cable trunk (pair - Windy nation welding cable) from the solar combiner.
The MPPT controller is good for 3000W @24V (each.) It has a parallel connection, port.
I’m just checking to see if this type of dual controller configuration can draw from a single combiner output, and if the parallel configuration setup is used to allow both controllers to sync MPPT activity. I don’t want to drag another large Cu cable trunk 90 feet from the 3rd string to a 2nd controller. The cable is expensive. I understand the 4AWG trunk is a bit overkill at about 25A today, and even ~37A if I add the 3rd string.
At 2000W my wiring is cool as can be. Using 8AWG Cu from panels to combiner with 8AWG MC-4 connectors. All exterior cable runs are in a watertight conduit with 8AWG ground. Using short 1/0 cable in battery bank and short 2/0 from battery bank to inverter. All cable is O2 free pure Cu.
4AWG from combiner to controller as mentioned, and very short 4AWG from controller to battery bank. This short run gets up yo about 80F under 90A load. Max amps will go down under parallel controller configuration.
Is there any special trick to wiring such a setup? What am I doing wrong?
Appreciate recommendations as this is my first Solar project.
Thanks.
