6 String Solar Combiner Box

[wolf pack]

Is it ok to run several panels in series to raise the voltage and keep the amps at 7.8 not to overload the 10 amp breaker. I bought a Sims 100 amp controller and a Sims 6000 watt converter. I do not have the combiner box yet, My goal is to run Twenty 280 watt panels into a 48 volt battery setup, ( Eight 6 volt 225 amp hour battery's) I posted several questions and am working on a off grid system for a single family house, Many Thanks, W.P.

[littleharbor]

Perfectly fine, up to the max Voc. of the controller. In cold climates and close to max Voc. the temp coefficients need to be figured into the equation. The current of the string of panels is the same as the current from a single panel. Bear in mind this input current isn't where you figure into the 100 amp current of your controller. The output will be much higher. Refer to the controllers specs for max wattage input numbers. Sounds like you will be wiring your panels into 3 panel strings x 6 unless your controller has a higher than 150 volt max Voc. with two spares. If your controller will do 200 volts you could go 5 strings of 4 and use all the panels, provided your controller can handle 5600 watts into a 48 volt system.

[wolf pack]

PV Specifications, I attached the specs from the controller, Looks like it cannot go above 155 volts, Being new to solar I am trying to avoid any serious mistakes, Thank you for your advice. W.P.

PV Operating Voltage:

• 15-155Vdc@12V
• 34-155Vdc@24V
• 50-155Vdc@36V
• 60-155Vdc@48V

Rated PV input:

• 12V - 1400 Watts
• 24V - 2800 watts
• 36V - 4200 watts
• 48V - 5600 watts

Electrical / Charging

• Maximum charging current: 100 amps / Maximum DC load current: 60 amps
• Max PV open circuit voltage: 155Vdc
• Battery types: gel, sealed, AGM, flooded, lithium, user defined (adjustable voltage)
• 4 Stage charging: bulk, absorption, float and equalize
• Bulk charge voltage: sealed 14.4V, AGM/Gel 14.2V, flooded 14.6V, user defined 10-15V
• Float charge voltage: sealed/AGM/Gel 13.7V, flooded 13.6V, user defined 10-15V
• Equalize charge voltage: sealed 14.6V, AGM/Gel 14.8V, flooded 14.8V, user defined 10-15V
• Low voltage reconnection: 12.5V
• Low voltage disconnect voltage: 10.5V (10.5-12.5V adjustable)

[littleharbor]

So you're maxed out panel wise. Problem is your batteries shouldn't see any more than 29 amps (13%) from the controller. How did you arrive at this size battery. charge controller and solar array? You really need to start with your loads and build your system from there.

[Ho jo]

Unless they are mounted flat With 5600 watts @48 volts. Triple the battery amps 675 would be a better match. ~13℅ charge rate.

[wolf pack]

I arrived at the battery size to match the 48 volts to start off, The charge controller I purchased at 100 amps from my reading on this forum. I used a online calculator to determine needed load, Ho jo, What do you mean Mounted flat, ? And are you saying triple the amount of battery's to 18 ? Many thanks, W.P.

[littleharbor]

I arrived at the battery size to match the 48 volts to start off, The charge controller I purchased at 100 amps from my reading on this forum. I used a online calculator to determine needed load, Ho jo, What do you mean Mounted flat, ? And are you saying triple the amount of battery's to 18 ? Many thanks, W.P.

Granted, 8 6 volt batteries in series is 48 volts. Problem is when your maxed out 100 amp controller hits those little batteries with a hundred amps of charging you will destroy them in short order. You need something like a couple strings of L-16 6 volt batteries.

[Ho jo]

With lead acid 10 ℅ charge rate is the sweet spot. 100 charge amps will support a 800 to 1200 ah battery bank. (1000 ah battery x 10℅= 100 amps)

[Mike90250]

Many of the larger charge controllers have adjustable output current limit, so you can match to your batteries.