EPEVER MPPT Solar Charge Controller 40A 150V PV Solar Panel Controller Question

[Solarson]

I have a newly purchased EPEVER MPPT with a maximum input voltage of 150 volts. I have four 310 watt Longi solar panels with a measured open voltage of 40.3 volts each. If I series all four panels there will be a potential combined open circuit voltage of 161.2 volts. I am sure the EPEVER has over voltage protection but, what will I risk if I try to use all four panels plugged in at 161.2 volts? Anyone ever pushed the voltage passed 150 volts on that MPPT?

Thanks in advance for your reply!

 

[snoobler]

I have a newly purchased EPEVER MPPT with a maximum input voltage of 150 volts. I have four 310 watt Longi solar panels with a measured open voltage of 40.3 volts each. If I series all four panels there will be a potential combined open circuit voltage of 161.2 volts. I am sure the EPEVER has over voltage protection but, what will I risk if I try to use all four panels plugged in at 161.2 volts? Anyone ever pushed the voltage passed 150 volts on that MPPT?

Thanks in advance for your reply!

This assumption is mistaken.

This is an absolute limit, and you need to allow a buffer for cold panel voltage increase, i.e., your Voc needs to be 10-20% lower than your MPPT's max PV limit if your panels might ever see 50°F or lower.

2S2P. Done.

 

[Bossrox]

You are wrong.

This is an absolute limit, and you need to allow a buffer for cold panel voltage increase, i.e., your Voc needs to be 10-20% lower than your MPPT's max PV limit if your panels might ever see 50°F or lower.

2S2P. Done.

That's right, I agree!

 

[snoobler]

Hmm... as I re-read my late night post, that may seem a bit harsh.

Please think of "You are wrong" as "This assumption is mistaken."

 

[Solarson]

Hmm... as I re-read my late night post, that may seem a bit harsh.

Please think of "You are wrong" as "This assumption is mistaken."

So, 150 volts is max....Got it. If I use 3 panels in series that will give me 121 Voc roughly, which would be about 20% lower input than the max.

Can I do that?

 

[snoobler]

Yes, but what are you going to do with the 4th panel?

To use all 4, 2S2P.

 

[Solarson]

Yes, but what are you going to do with the 4th panel?

To use all 4, 2S2P.

I was thinking about running a small 12 volt system along side of it [(1) panel, (1) 20amp MPPT & (1) 12volt LiFePO4 100ah battery). All really cheap parts but functional. I will use that to light up my boathouse with 12 volt LEDs.

 

[snoobler]

I was thinking about running a small 12 volt system along side of it [(1) panel, (1) 20amp MPPT & (1) 12volt LiFePO4 100ah battery). All really cheap parts but functional. I will use that to light up my boathouse with 12 volt LEDs.

Rather than run a completely separate system, you can get a DC-DC converter for cheap. You didn't mention what your system voltage is, but there are 24/36/48V to 12V converters that cost < $50 vs. outfitting a new new systems for several hundred $.

 

[Alphacarina]

Hmm... as I re-read my late night post, that may seem a bit harsh.

Please think of "You are wrong" as "This assumption is mistaken."

Class act! It was a 'bit harsh' IMO (I've been guilty of the same) so realizing that and admitting to it early on was the 'right' thing to do, IMO

Don

 

[snoobler]

Class act! It was a 'bit harsh' IMO (I've been guilty of the same) so realizing that and admitting to it early on was the 'right' thing to do, IMO

Don

Nah. The class act wouldn't have been more aware in the first place. The second class act would have thought to edit his post as moderators can edit their own posts indefinitely. The third class act revised it three days later...

 

[jaahn]

I was thinking about running a small 12 volt system along side of it [(1) panel, (1) 20amp MPPT & (1) 12volt LiFePO4 100ah battery). All really cheap parts but functional. I will use that to light up my boathouse with 12 volt LEDs.

Hi Solarson
Hi a newbee here on this forum. If it was mine I would not waste a big panel on a few leds, as you could get any small panel to do that. I would do what was suggested and run two strings of 2 panels into the EPever and that would be excellent into a 12V battery and good into a 24V system .
But we do not know what your needs are.
Just a comment on the common habit of allowing the built in self protection to be used as continuous trimming for over voltage. That is crazy and from my experience leads to short life. Running things at a comfortable margin under the max ratings leads to a long life usually.
Jaahn

 

[Solarson]

I forgot to mention I am building a 24 volt system. I get if I want to use all four panels into the EPEVER MPPT I need to do 2S2P. I understand which connectors to purchase to do 2S2P. I have to run the wire from 30 feet away. Will this 10 gauge wire do the trick? https://www.amazon.com/gp/product/B074S12G91/ref=ppx_yo_dt_b_asin_title_o05_s01?ie=UTF8&psc=1

As always, thanks for your reply!

 

[snoobler]

2.1% voltage drop.

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

 

[Solarson]

2.1% voltage drop.

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

Was looking for one of those....thanks!!!