Solar generation in rain/cloudy conditions

[cavedog]

That is a lot of voltage drop over the cable imho. How are you reading bms voltage now?

The Pace bms app via remote monitoring on my phone. In solar assistant which I just setup I had to select Inverter.

That is how I saw the difference between the inverter and what the bms is showing.

Is it a lot? The cable is not even long. Its the cable that came with the Ecco battery

 

[Lupus]

Bought a solar assistant for my setup. Forgot to but the bms cable since the inverter is using voltage mode. Sigh.

I got one donated to me thanks to a forum user, but my assistant is in the house and the batteries are in the garage about 100m away from each other. Not sure how the BMS will work to be honest

 

[wingnut771]

The Pace bms app via remote monitoring on my phone. In solar assistant which I just setup I had to select Inverter.

That is how I saw the difference between the inverter and what the bms is showing.

Is it a lot? The cable is not even long. Its the cable that came with the Ecco battery

Yeah, I would double the thickness then and get high quality tin coated copper lugs hydraulically crimped (cold welding) to remove any oxygen so the strands become solid.

 

[cavedog]

Yeah, I would double the thickness then and get high quality tin coated copper lugs hydraulically crimped (cold welding).

I thought the cable was a bit on the thin side but even chatgpt said the thickness is correct.

 

[Lupus]

I thought the cable was a bit on the thin side but even chatgpt said the thickness is correct.

Cable for BMS just plugs into the ethernet, rs or crimps on the battery

 

[wingnut771]

I thought the cable was a bit on the thin side but even chatgpt said the thickness is correct.

It could just be cheap aluminium cable and or cheap lugs. Get some 50mm2 welding cable or as thick as can fit in inverter. What is your thickness?

 

[denmendez65]

It could just be cheap aluminium cable and or cheap lugs. Get some 50mm2 welding cable or as thick as can fit in inverter. What is your thickness?

That is way overkill. He has 1 battery, 5kW inverter. If he has a 25mm2 which I think he does that is more than enough for his system. He can add a second battery and pull 100A all day and still be fine with 25mm2.

 

[wingnut771]

That is way overkill. He has 1 battery, 5kW inverter. If he has a 25mm2 which I think he does that is more than enough for his system. He can add a second battery and pull 100A all day and still be fine with 25mm2.

What is an acceptable voltage drop over 1m cable in your opinion under 100A load? Then get 25mm2 welding cable with high quality lugs.

 

[denmendez65]

What is an acceptable voltage drop over 1m cable in your opinion under 100A load? Then get 25mm2 welding cable with high quality lugs.

0.7 is fine in my opinion.

100A with my 35mm2 cable i get about 0.7V also. 25.6 with TV on etc so about 300W. And about 24.9 with a 2kW toaster running. I do have GEL batteries though, so maybe you have a point. Lithium has voltage drop but it should not be as much as my batteries. But I have limited experience with Lithium.

 

[wingnut771]

0.7 is fine in my opinion.

100A with my 35mm2 cable i get about 0.7V also. 25.6 with TV on etc so about 300W. And about 24.9 with a 2kW toaster running. I do have GEL batteries though, so maybe you have a point. Lithium has voltage drop but it should not be as much as my batteries. But I have limited experience with Lithium.

Im talking about voltage drop across the cable so measure voltage at battery terminal and then inverter terminal and minus the difference. Imho, there shoukd be none.

 

[denmendez65]

Im talking about voltage drop across the cable so measure voltage at battery terminal and then inverter terminal and minus the difference. Imho, there shoukd be none.

What is he talking about? Voltage drop across the cable or across the battery? Did he actually measure the voltage across the battery under load and measure the positive and negative on his inverter connections? Whatever the BMS says and what the inverter says I wouldnt pay much attention to. Use 1 device to measure the 2.

0.7 across the cable would be a lot.

 

[wingnut771]

What is he talking about? Voltage drop across the cable or across the battery? Did he actually measure the voltage across the battery under load and measure the positive and negative on his inverter connections? Whatever the BMS says and what the inverter says I wouldnt pay much attention to. Use 1 device to measure the 2.

0.7 across the cable would be a lot.

Without a multimeter he is taking the inverter voltage reading and the bms voltage reading. I would say both are accurate but we will never know without double checking by physically measuring both sides. Yes 0.7V across the cable is a lot indicating chinesium cable and lugs.

 

[denmendez65]

Without a multimeter he is taking the inverter voltage reading and the bms voltage reading. I would say both are accurate but we will never know without double checking by physically measuring both sides. Yes 0.7V across the cable is a lot indicating chinesium cable and lugs.

My inverter is about 0.2V out compared to the dedicated voltage meter I have with the screen on 24/7 (rather than pressing a button to turn the inverter screen on everytime I want to look when in the room).

My multimeter is 0.2 out compared to the inverter and 0.4 compared to the voltage meter. Make of that what you will.

Best to use 1 multimer and measure the 2 points with it. Then he will know.

 

[wingnut771]

My inverter is about 0.2V out compared to the dedicated voltage meter I have with the screen on 24/7 (rather than pressing a button to turn the inverter screen on everytime I want to look when in the room).

My multimeter is 0.2 out compared to the inverter and 0.4 compared to the voltage meter. Make of that what you will.

Best to use 1 multimer and measure the 2 points with it. Then he will know.

We will never know because @cavedog doesn’t have a multimeter.

 

[cavedog]

We will never know because @cavedog doesn’t have a multimeter.

Excuse me. I might be an IT nerd but I do have this device you claim I don't have.

 

[denmendez65]

Excuse me. I might be an IT nerd but I do have this device you claim I don't have.

Ey, dont confuse it with a graphics card not or ethernet switch

 

[wingnut771]

Excuse me. I might be an IT nerd but I do have this device you claim I don't have.

Oh, didnt you say you couldn’t check voltages earlier because you didn’t have one? So are the inverter and bms readings accurate?

 

[cavedog]

Is this grid voltage within normal limits? 250V seems a bit high.

 

[Hazy_Living@79]

Is this grid voltage within normal limits? 250V seems a bit high.

Isn't that normal range? Inverters reading 249.0V by me.

 

[cavedog]

Isn't that normal range? Inverters reading 249.0V by me.

I'm not sure is the target for grid not 230V?