Solar charging question

[eTouringOldie]

I know that I could 'be empirical' to answer this question, but I thought I see if anyone knows off the top of their head:

Is it better to run more than one panel in parallel or series when connecting to the charging controller?

Background, I'm charging a 48V battery using a boost mode MPPT charging controller. It can accept any input (solar panel output) voltage, as long as it's below the battery charging voltage I set the controller output to (in this case 54V).

So in parallel to get higher input current to the charging controller? Or in series to get higher input voltage? Or ... it doesn't matter, basically the same results either way? Or ... it depends on the controller?

Panels are nominal 12V. I'm connecting 2 or 3 panels to the charging controller.

Thanks!

 

[smritte]

Your numbers are correct but I base my system on the losses involved.
My current set up is 200 watt (12v) on my trailer and two folding 180 watt. My plug's and patch cords are set to run either parallel or series.

Series cant be used unless your charge controller can handle the input. I run 100 volt controllers. You also want to check the panel spec's to make sure they can handle your series voltage.
"If" I have to run my auxiliary (180) watt panels, it because my trailer is parked in the shade.

The question is now, how far away from your controller are your panel(s). I have two high quality 10 gauge cords, about 50 foot each.
With a single panel 50 foot away, I lose about .75 amp in the circuit (direct sunlight). If I parallel two at that distance I lose almost two amps. If I series two, I lose less than .5 total due to the higher voltage.

Parallel is easier to deal with and if your loss isn't significant, that's what I would do. If you have to remote your panels, measure and see what the difference is.

My experience in this me playing around with diffrent configurations over the last two decades. it's common for me to camp for 3-5 days.

 

[WaterWiz]

smritte nailed it.

This is my $.02

Your charge controller has at least two limits. Max current (amps) input and Max PV (voltage) input. There is probably a third minimum PV input to activate the charge.

Here is an example: Your charge controller can handle 100 PV and 10 amps input. Your solar panels have 40V output (no load, direct sun) at 6 amps output each (240W panel). In this scenario, you can use two panels in series to 80v input with 6 amps to the charge controller. If you put the panels in parallel you would get 40 volts and 12 amps input to the charge controller which would exceed the input limit of the charge controller on amps.

In the above scenario, you could not add three panels in series because you will exceed the PV input. Most controllers will immediately shut down in this scenario (PV overvoltage). You can however in most cases get away with exceeding the current on some charge controllers as it will clip the current at the max input. In this case, your charge controller would limit your parallel input to 40v at 10 amps = 400 watts max vs in series 80 X 6 = 480 watts. I.e. you will only get 400 watts out of your 480-watt panels in parallel (not including line losses, see smritte response)

I generally prefer a high PV input charge controller because high voltage low amps are better for me than low voltage high amps (big wire). I live in FL. You may be in a colder, low-light climate where calculations differ somewhat

Hope this makes sense

 

[Hozer]

OK this is how I am going to do it:

Video on how to do solar:


Here is the "SOLAR BOOSTER" I am going to buy. 600 Watt Version: ( 600 watts solar max in from solar )

https://www.amazon.com/Controller-Display-Regulator-Waterproof-Lithium/dp/B0BRZ33D2X
Here is the 300 watt version: ( 300 watts solar max in from solar )

https://www.amazon.com/SUNYIMA-Cont...f8-a9d9-2a2dd7dd7e66&pd_rd_i=B0B7WWY5S3&psc=1
How to EV Charge your bike!!



Hope that helps

 

[eTouringOldie]

OK this is how I am going to do it:

Video on how to do solar:


Here is the "SOLAR BOOSTER" I am going to buy. 600 Watt Version: ( 600 watts solar max in from solar )

https://www.amazon.com/Controller-Display-Regulator-Waterproof-Lithium/dp/B0BRZ33D2X
Here is the 300 watt version: ( 300 watts solar max in from solar )

https://www.amazon.com/SUNYIMA-Cont...f8-a9d9-2a2dd7dd7e66&pd_rd_i=B0B7WWY5S3&psc=1
How to EV Charge your bike!!



Hope that helps

I have what looks like the exact same boost charger. I'm just wondering which is the better approach as far as connecting multiple panels.

Parallel for higher input current, or Series for higher input voltage?

 

[Hozer]

I have what looks like the exact same boost charger. I'm just wondering which is the better approach as far as connecting multiple panels.

Parallel for higher input current, or Series for higher input voltage?

I would go in series. Why? it will pretty much match your ebike charger just to play it safe when using that solar booster. IMHO

 

[HumanPerson]

@Hozer
I've left @Anton a msg concerning an area just for Solar Charging.
He's busy with other commitments at the moment and will hopefully see this soon and make the Solar area

Just know we'll continue to poke @Anton in the belly with pencils 'til he see this lol