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# Thread: mppt charge controller - ZLPOWER ??

1. ## solar panel connection

I have a small {lol} question in which way is the best/better way to wire panels. I'll use 4 panels, each 65watt x 3.5 amp x 18vdc. I guess im trying to get more amp's. I now have them all in parallel. Should I take Two and wire them in parallel and then take those and connect them to the other Two in Series. It would them be 36 vdc, ...BUT would it be 3.5 +3.5= 7AMPS, Then going through the Two in series 7 + 3.5 =10.5 amps at 36 vdc.
Tks
John

2. watts=voltage x ampers

watts is fixed

so the lower the voltage, then the higher the amperage. So wire them in series to keep the voltage down....if this is what you really want to do.

EDIT: parallel...not series. + to + to + to + - to - to - to -

3. If you really have a MPPT controller you want the amperage to be as low as possible, and the voltage as high as possible. You would want to wire all 4 panels in series which would give you 72 volts @ 3.5 amps.

If you have a PWM controller then you only have one lousy option to wire all 4 of them in parallel assuming you are operating a 12 volt battery which gives you 18 volts @ 14 amps.

4. Originally Posted by pmaru77
So wire them in series to keep the voltage down....if this is what you really want to do.

5. Originally Posted by Sunking
Did I screw up again? series parallel series parallel.......I better stick to +'s and -'s. I always get it backwards except when actually wiring.

6. Originally Posted by pmaru77
Did I screw up again?
Yeah you did.

Series Circuits Vt = V1 + V2 + V3... I1 = I2 = I3...
Parallel Circuits It = I1 + I2 + I3... V1 = V2 = V3....

So with the example given of 4 panels with 18 volts @ 3.5 amps:

Series = 18 + 18 + 18 + 18 = 4 x 18 = 72 volts @ 3.5 amps = 252 watts
Parallel = 3.5 + 3.5 + 3.5 + 3.5 = 4 x 3.5 = 14 amps @ 18 volts = 252 watts

7. ## Solar cell panel

ok. so I'll wire the in series up to the voltage of the grid tie inverter.
tks
John

8. Originally Posted by conntaxman
ok. so I'll wire the in series up to the voltage of the grid tie inverter.
tks
John
I thought you wanted max amps? then parallel
max voltage ...then series.

I think you want max voltage.

9. ## solar panel connection

Originally Posted by pmaru77
I thought you wanted max amps? then parallel
max voltage ...then series.

I think you want max voltage.
-------------------------
Guess i was tring to get both. From four panels now im only drawing 8 amps at about 25 volts.

10. This forum has been very informative to me since im just getting into solar power.

I just want to share my experience with this mppt controller, it came in an unlabaled box.

My system at first setup was 2 x120w parallel conection mono panel, a china 600w inverter and locally produced 100ah flooded battery that is connected with the zlpower sl-40a.

Max charging amp from 2 parallel 120w panel was 11amp. So no big increase even with mppt

When i connected the panels as series, i got 14amp. So i do think this mppt really works.

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