EPEVER 2210AN

[mathewhgreen]

Hi

The controller I have is capable of upto 100volts of panel voltage.

I have two 290watt panels I want to put in series having had them in parallel for ages. I have three of them in parallel at the moment.

I’ve not had an issue with over-panelling as the total power was nearly 900 watts as the voltage was never higher than 35volts. The amps being controlled by the controller.

If I put two of them in series which will total about 70volts will it be ok still?

Just checking before I change

I just fried what I thought was the same controller but the voltage was limited to 60volts. A capacitor has popped so hopefully changing that out will fix it. I can’t see any other damage.

Thanks
Mat

 

[MisterSandals]

What is the Voc of your 3 panels. What is he coldest temp that your panels will be?
The voltage increases about .35% for each deg below 25C where they are rated.
If your panel lists the temp coefficient, a better calculation for temp compensation can be made.

 

[mathewhgreen]

I’ll only be using two panels in series so the maximum voltage will be 70volts. Both capable of 8 amps. 35 Voc each. It’s around 7C atm.

 

[MisterSandals]

2 panels will easily be under your 100V input limit.

Why would you switch to 2 panels in series from 3 in parallel. That sounds like it will produce 1/3 less power.

 

[MisterSandals]

If you want to maximise your over panelling, you should put your 3 parallel panels spread east to west. The south east facing panel will start charging as he sun comes up, the west-ish panel will charge late in the day. You will max out your 10A SCC for most of the day, probably doubling a south-only facing array.

 

[mathewhgreen]

I read something the other day about when the voltage from the panels drops below 15v it has trouble charging efficiently? So I thought during the winter I would put them in series as two panels generating say 12v each would make 24v…

Have you heard about this sort of thing?

 

[MisterSandals]

Have you heard about this sort of thing?

Oh yea, that’s a real thing. There is definitely some headroom voltage for most SCCs to start (5V) is the number bandied about. Once started, my impression is they can run just a couple volts over charging voltage.

If your panels are struggling to make 15V when cloudy, series connected panels is a good solution. If you can find a 4th “similar or exact” panel, 2S2P is a popular configuration. And you could point one string slightly east and the other slightly to lengthen the charging hours.

Or just run 2 in series and get a cheapie 2nd SCC for your other panel. I do recommend investing in quality SCCs though.

 

[mathewhgreen]

Could I put two in parallel and then that pair in series with another?

Total voltage would be 70v still and I could use all my panels…

 

[MisterSandals]

Could I put two in parallel and then that pair in series with another?

“another” what?
Another single panel with the same specs as the other panels?
3 equivalent panels, 2 in parallel in series with the 3rd would be severely affected and be no better than 2 panels.

Another equivalent pair of 2 panels in series? Then yes.

Another single panel (bigger) equivalent to the combine parallel pair? Then yes.

 

[mathewhgreen]

I have three panels the same.
Two on the roof and one on the back of my Moho at 90 degrees to the ground facing south.
I was thinking to keep the voltage up I could have the two on the roof in parallel and then that pair in series with the one on the back.