Voltage drop from solar controller
or: Here we Go Again. Still trying to get my 420 Watts of solar to fully charge my 484 AH of battery. (Currently in southern Mexico.) Layout: 2 80 Watt panels and 2 130 Watt panels in paralle...
Forum Discussion
Yes, it seems that the good deals at Rallies aren't always! Of course it seemed like a good idea at the time, experience has proved otherwise--always learning.
Almot: I certainly agree that the remote voltage and temp sensing is critical down here. Running a parallel wire is good in theory but it isn't going to happen here. I'll come back and post a picture here to show why.
Pianotuna: Don, input voltage measured at the controller was 15.3 It would seem that there is more voltage drop on the input side than there should be. All 4 panels are wired in parallel with lengths of #10 wire maximum length about 8 feet at a guess, from the most distant panel to the junction point on the roof. From the junction point to the controller is another 8 feet max of #10.
The sky is quite clear today but there is a lot of varying high thin cloud. Most I have been getting out is 18Amps. I went up on the roof and checked current out of the 130 Watt panels: measured 8A once from one, measurements a few minutes apart ranged from a low of 4.8, most common was about 6.5A. The 80 Watt panels have parallel conductors right into the junction box so I wasn't able to use the clamp-on ammeter.
I had increased the output voltage limit a bit, when it got up to 15.45 I turned it down a little, now reading 14.90V. Good news, the Xantrex remote battery voltage continued rise, finally went up to 14.5V. That was when then BlueSky was showing 15.45V. That was pretty close to the best sun angle on the panels and a bit past solar noon.
Now, 14:20 local time, about an hour later, the Xantex is reporting 14.3V at the batteries, the BlueSky reading 14.9V, 11.5A, the light flashing "Charged", or according to the manual, battery is 90% charged or better and is now at a Constant Voltage Rate.
More good news, I have not had any Hi Bat or Hi Bat Temp warnings from the Xantrex. But I'll check electrolyte levels later. That's just a matter of sticking the tube in a bottle of distilled water and giving the bulb a squeeze or two. I used to have to retract the slide and disconnect and remove two of the batteries to do that!
Over the next few days I'll watch the BlueSky output voltage.
Almot: I certainly agree that the remote voltage and temp sensing is critical down here. Running a parallel wire is good in theory but it isn't going to happen here. I'll come back and post a picture here to show why.
Pianotuna: Don, input voltage measured at the controller was 15.3 It would seem that there is more voltage drop on the input side than there should be. All 4 panels are wired in parallel with lengths of #10 wire maximum length about 8 feet at a guess, from the most distant panel to the junction point on the roof. From the junction point to the controller is another 8 feet max of #10.
The sky is quite clear today but there is a lot of varying high thin cloud. Most I have been getting out is 18Amps. I went up on the roof and checked current out of the 130 Watt panels: measured 8A once from one, measurements a few minutes apart ranged from a low of 4.8, most common was about 6.5A. The 80 Watt panels have parallel conductors right into the junction box so I wasn't able to use the clamp-on ammeter.
I had increased the output voltage limit a bit, when it got up to 15.45 I turned it down a little, now reading 14.90V. Good news, the Xantrex remote battery voltage continued rise, finally went up to 14.5V. That was when then BlueSky was showing 15.45V. That was pretty close to the best sun angle on the panels and a bit past solar noon.
Now, 14:20 local time, about an hour later, the Xantex is reporting 14.3V at the batteries, the BlueSky reading 14.9V, 11.5A, the light flashing "Charged", or according to the manual, battery is 90% charged or better and is now at a Constant Voltage Rate.
More good news, I have not had any Hi Bat or Hi Bat Temp warnings from the Xantrex. But I'll check electrolyte levels later. That's just a matter of sticking the tube in a bottle of distilled water and giving the bulb a squeeze or two. I used to have to retract the slide and disconnect and remove two of the batteries to do that!
Over the next few days I'll watch the BlueSky output voltage.
