6500EX, PV Power Limitation & Operational Temperature Questions

[BajaOffGrid]

Hello!

I couldn't find anything definitive searching, please let me know if this has been discussed at length somewhere else. The manual is not very clear, is it only amps it limits? is it only one limit from 18 > 9 at 85 degrees and that is it? or does it limit more at higher temperatures?

Setup:
EG4 6500EX - Fully Offgrid
(4) EG4 Lifepower4 48v Batteries
(1) String of (12) 300watt Panels in Series feeding each MPPT (2 strings total)
300 Watt Panel Specs - VOC 37.04, Vmp 31.70, Isc 9.9, Imp 9.48

Around 12pm, Sun right overhead, clean panels, and no clouds this is what I am seeing (it fluctuates around a bit obviously):

PV1: 313v, 7.2a, 2.27kw
PV2: 283v, 8.7a, 2.48kw


Question:
I am trying to understand if I am being throttled, and to what extent. The temperature in the room is almost never below 85 degrees due to the heat these things put off. Outside temps are roughly 91-94 during the day 75-79 at night. I wouldn't be surprised if the room exceeded the max 131 degrees during the day. It's a sauna in there.

1. Do these outputs look correct?
2. Am I being throttled? voltage? amperage?
3. Any tricks to getting closer to the 444v / 3.6kw max?
4. Would adding an EG4 MPPT100-48 solve anything? (I don't see the temperature limitations in the manual)
3. Any other issues you guys may see with these temps? I don't think adding an AC unit to this room will solve anything as I believe it would consume more than I would make up for with efficiency.


Thanks so much, guys!

 

[ungrounded]

Are the panels clean?

 

[timselectric]

Are the panels clean?

clean panels

 

[Quattrohead]

It does seem low but possibly within environmental variables. How about trying just one string at a time and see whether you can get more output from a single string.
Do you both have both strings on one inverter or a string per inverter?
And where are you and what does an online PV calculator tell you you should be able to get?

 

[BajaOffGrid]

It does seem low but possibly within environmental variables. How about trying just one string at a time and see whether you can get more output from a single string.
Do you both have both strings on one inverter or a string per inverter?
And where are you and what does an online PV calculator tell you you should be able to get?

I can try disconnecting one string and see what happens tomorrow around noon.

This is two strings, one going into each MPPT on the SINGLE 6500EX.

I am in Baja California Sur, Mexico (near Cabo San Lucas). Do you have a link to a PV calculator I can try?

 

[Quattrohead]

https://pvwatts.nrel.gov/ is one of them.
Next day experiment is 1 string on each inverter. Have fun !!!

 

[BajaOffGrid]

https://pvwatts.nrel.gov/ is one of them.
Next day experiment is 1 string on each inverter. Have fun !!!

Thanks, I just checked the temps, it's about 105 in the room, 115 at the MPPT with the laser temp gun

 

[BajaOffGrid]

Day Two, 12pm, same temp (90 degrees outside)

Two Strings Connected
PV1: 2.27kw, 7.2a, 313v
PV2: 2.48kw, 8.7a, 283v

One String Connected:
PV1: 2.44kw, 7.5v, 324v

Doesn't seem like anything changed, it seems to jump 200-400watts normally.

Temperatures are still about the same ~90 in the solar room, with the MPPT part of the inverter registering ~115.

I just cleaned the panels, but I could always try again tonight to get them spotless...

Let me know your thoughts, 5KW out of 7.2KW of panels seems low. Could it be the panels are hot? not enough ventilation below?

 

[Quattrohead]

They could just be very tired panels. I have used Panasonic panels that seem to have no problems producing their full power on occasion and what were brand new LG panels that can never manage it, however none of them are installed in ideal conditions and they all get bloody hot here in Florida.

 

[BajaOffGrid]

They are less than 3 months old, and when they were brand new PV1 was pulling 3.43K (out of 3.6kw). Something has changed, it's definitely gotten hotter, and they are definitely a bit dirtier.

So either something is being throttled, or they are losing efficiency at the panel because of the heat?

 

[Quattrohead]

What make and model ?
Can you cool the inverter somehow, even just to test.

 

[BajaOffGrid]

Yes I've been leaving the closet door open so the AC can kind of trickle in there, its cooler in there for sure, but I doubt it goes below 85 degrees.. Im not sure if I can get it below 85 even with AC on full blast and fans blowing the cold air in but will try... I dont know that my laser temp gun is very good at getting the ambient temp, but the walls dont seem to drop below 90...

 

[PunchySunshine]

I believe the max operating temp for the 6500 is 105 degrees Fahrenheit. I'd check the manual for more exact information but get a fan in that room or something IMO.

 

[Adam De Lay]

Based on the manual, the operating temp range is -10C to 40C (14F to 104F).

 

[Zwy]

They are less than 3 months old, and when they were brand new PV1 was pulling 3.43K (out of 3.6kw). Something has changed, it's definitely gotten hotter, and they are definitely a bit dirtier.

So either something is being throttled, or they are losing efficiency at the panel because of the heat?

In March with clear skies, good sun, I could get 8Kw yield. Now in July with higher temps, haze in the sky from humidity, high clouds, Canadian wildfire smoke and panels tilted back with some dust on them, even dust in the air is greater. It's hard to get 8Kw. The sunlight isn't as direct due to atmospheric conditions. March on the other hand had lower temps with very clear sunlight and skies.

3 months can make a huge difference. But with the longer days it makes up for some of the loss due the atmospheric conditions.

Any SCC will have a temp limit, it will throttle back the amps as that is where the heat comes from. The EG4 SCC will limit amps too if temps are high. Clean your filters monthly.

 

[BajaOffGrid]

Thanks guys, I do think it is a combination of things, they aren't as clean as they were new, and it is much hotter.

The room doesn't seems to get over 95, but the case of the 6500EX (where the PV input is) gets up to 110-117.... Keeping the door open and adding a fan. It's too bad this inverter sounds like a jumbo jet.. I'm thinking of switching the solar over to a Victron MPPT RS due to the noise and temperature limitations on this thing. If heat is the real issue here, I would think it would only help the 6500EX last longer moving the PV loads over to a separate SCC and if its quiet then its a double win...

 

[Quattrohead]

Well you could take the trade in offer for the EG 18k, this thing is dead silent until it has 6 kilowatts of power going in or out.

 

[akitawpo]

I have a 6000ex and that is at around 37-38c deg ambient temps daily with a fan blowing air into it and a extractor taking out "heat" from the room it is at. Solar Assistant reports a temps of 53-55c when close to 5000watts of PV are coming in to charge and cover the loads. Air filters are cleaned weekly.

 

[Mattb4]

So PV one is running at 2270w/3600w=63%
PV two is 2480w/3600w=69%

I would think that is not all that out of line for having real hot days. The discrepancy between the 2 arrays might need some investigation if they are identical in every way other than output. It would be a good idea to check every connection for excessive heat.

Your AIO is likely not throttling but it is not good to keep it at such high ambient temperatures. It can cause internal component failure.

 

[akitawpo]

Thanks guys, I do think it is a combination of things, they aren't as clean as they were new, and it is much hotter.

The room doesn't seems to get over 95, but the case of the 6500EX (where the PV input is) gets up to 110-117.... Keeping the door open and adding a fan. It's too bad this inverter sounds like a jumbo jet.. I'm thinking of switching the solar over to a Victron MPPT RS due to the noise and temperature limitations on this thing. If heat is the real issue here, I would think it would only help the 6500EX last longer moving the PV loads over to a separate SCC and if its quiet then its a double win...

Forgot to add in my prevoius post I decided to add a Victron 150/35 to move some solar away from my 6000ex for the same reason (heat). Trying to not use the 6000s full SCC to its full power and using the victron to supplement. Currently the 6000ex is charging at 60amp and the victron at 20amps. 80 amps total / 26amps each for three 48v LLs. I'm expecting two more batteris for a total of 5. Guess will have to push the victron a little harder.