I have a 100watt renogy panel that is giving me around 19volts and 4.5 amps at the leads going into the controller. The controller is a renogy wanderer 30amp connected to two 6v batteries in series. When connected and using the Bluetooth app I am seeing the controller getting at most 12.9 volts and 1.5 amps. I let the battery drop and reconnected and the volts from the panels were just slightly over the battery voltage level. It never goes into a boost charge mode, I have tried a brand new adventurer charge controller and got the same results. All of this was confirmed with my multimeter. I have checked all wiring multiple times and disconnected everything from the batteries except the charge controller and panel. This system worked great before, then at some point it just stopped.
Worked before but now won't
- Thread starter Jermy78
- Start date
Bob142
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Welcome to the forum!
Some Questions:
The Renogy Wanderer 30A charge controller is a PWM controller. That style drops the panel voltage to nearly battery voltage when charging so your observed readings don't seem out of the ordinary to me.
Some Questions:
- Just to be clear: does this mean the system used to complete a full charge (going into boost then eventually float modes) and now it doesn't?
- Also, what kind of batteries do you have? (Flooded lead acid?)
- What is their capacity in Ah?
Bob142
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Do you have any other charge sources?
A single 100W panel to keep a 210Ah battery bank fully charged is well short of what is normally necessary. Sounds like you are likely chronically undercharging the battery bank which is bad for it long term.
What are the loads on the system?
With that single panel, even if you got 80W from it for 4 hours that's 320Wh. Your battery bank has 210Ah*12V = 2,520Wh (1,260Wh useable if you keep discharge to 50%). You'd need 4 days of full sun to replenish the batteries if you discharged them to 50%.
On the surface it seems like you need two or three more panels to bring your solar charging up to a level that could sustain the battery bank (assuming some reasonable loads on the bank during the day and night).
A single 100W panel to keep a 210Ah battery bank fully charged is well short of what is normally necessary. Sounds like you are likely chronically undercharging the battery bank which is bad for it long term.
What are the loads on the system?
With that single panel, even if you got 80W from it for 4 hours that's 320Wh. Your battery bank has 210Ah*12V = 2,520Wh (1,260Wh useable if you keep discharge to 50%). You'd need 4 days of full sun to replenish the batteries if you discharged them to 50%.
On the surface it seems like you need two or three more panels to bring your solar charging up to a level that could sustain the battery bank (assuming some reasonable loads on the bank during the day and night).
Sorry I lacked some information. This is on a travel trailer so I also charge with shore power or generator when needed. But I do use this to maintain and at times of only light usage to top off my batteries during the day. Previously I would achieve 25 to 30 AH back in the batteries during a long summer day. Now I'm lucky to get 4AH. And according to the Bluetooth app it states "start charge" because it's never achieving the current needed to top off the batteries. Almost like it's just trickling 12.9 volts and less than one amp.
Bob142
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That rounds out the picture. How old are the batteries? Can you charge them fully with shore power/genny? Wondering if you have a bum battery…
MisterSandals
Participation Medalist
Have you tried a different solar panel?
Bad connections are often the issue. Specially those going into the pwm or the mc4 that fail suddenly after sometime.
To test the panel I find a 20w12v bulb (car brake light bulb) on the end of cable with alligator clips are best.
The intensity of the light gives a real insight into pv in general compared to a multimeter
chrisski
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All I can add is measuring the short circuit amperage To see if this has changed since you measured the amps last.
This is kind of an art. Although my panel puts out up to 5 amps to charge a battery when the sun is high in the sky, I’ve only measured it an hour or two after sunrise and I’ve gotten only 2 to 4 amps depending on the angle of the sun. If I did this at noon in the summer, I‘d expect 6 short circuit amps.
This is kind of an art. Although my panel puts out up to 5 amps to charge a battery when the sun is high in the sky, I’ve only measured it an hour or two after sunrise and I’ve gotten only 2 to 4 amps depending on the angle of the sun. If I did this at noon in the summer, I‘d expect 6 short circuit amps.
MisterSandals
Participation Medalist
Why wouldn't you us a DMM where you get actual volts to usually 2 decimal places and amps to 2 decimal places?
chrisski
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If those are measurements off the DMM, I recommend looking for connections as mentioned. Could be anything like a butt splice, MC4 connector, or even screw terminal into the SCC.
I used to work as an electronics technician, and some corrosion or bad connectors would be hidden very good. In my truck, the large battery wires like to fray in places you can’t see and causes large losses with higher amps, but pass continuity fine.
I used to work as an electronics technician, and some corrosion or bad connectors would be hidden very good. In my truck, the large battery wires like to fray in places you can’t see and causes large losses with higher amps, but pass continuity fine.
Suggest you try it out and see for yourself.
I must admit a look at the back and front, then a dmm for V across the diodes, any V as long as they are the same, has weeded out any bad panels that I have encountered. Get that far they are good enough to convert and test the amps later.
MisterSandals
Participation Medalist
I do it all the time. Whats the problem with using a DMM to check volts and amps of a panel?
The only issue i ever had, testing a series string w/o thinking it thru, was exceeding my 10A fuse. But the OP has panels that are 4.5A. It actually takes less than a minute to test with a DMM.
See video by the late Solarqueen:
I need help understanding the amperage of my PV arrays
You are correct. I need 15a breakers. I can swap out the fuses for 15a for now. I am adding a combiner box once I get my new battery built. At that point all my breakers will be the correct 15a per string. I see an issue with polarized breakers. Unless you can get non-polarized breakers, I...
diysolarforum.com
There is nothing. Like I said I do it that way.
Still saying the best way, specially for anyone starting out with their single 12v panel, is the light bulb test and on a day with inconsistent cloud cover. You need to try it out to get a better understanding!
Lets see - 210ah lead acid battery that wants to see 0.1C to stay healthy and not get sulfated.
Your 4.5A from a 100 watt panel is about 0.02C. Not enough to keep a flooded healthy - welcome to sulfation and stratification. Your battery will die early. Add to that limited solar hours daily.
A rethink / redesign is needed, unless you are getting scrap batteries, continuing on will become very costly and a lifetime of poor performance.
Your 4.5A from a 100 watt panel is about 0.02C. Not enough to keep a flooded healthy - welcome to sulfation and stratification. Your battery will die early. Add to that limited solar hours daily.
A rethink / redesign is needed, unless you are getting scrap batteries, continuing on will become very costly and a lifetime of poor performance.
Texas-Mark
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Not sure how subjective light bulb intensity is better than the resolution/accuracy of a DVM. As a quick go/no go test, sure, but a bulb probably won't tell you that you have a X% current reduction, especially if you have no frame of reference. The OPer only has one panel. How is he supposed to know how bright the bulb is supposed to be?
I wonder if you are smoking your Wanderers by not following the procedure of having the batteries attached *first*, and then connecting panels last?
I see that mentioned a few times in the Wanderer manuals, and is thing we did for decades with other controllers in the past. Although these days, they aren't supposed to fail - either not work at all, or go into a fail-safe float-only condition, but apparently the Wanderers are like those in the past that demand battery connections first *before* attaching a panel.
One gotcha' about this is if you are swapping out batteries, and forget to disconnect your panel, you may end up in that state with just a panel connected and no battery - and smoked controller.
I had a propensity to get this wrong myself a few times, so I kept a spare pwm controller on the shelf - or if for some reason the battery itself went open-circuit, I'd have a spare controller to put back into service asap.
I see that mentioned a few times in the Wanderer manuals, and is thing we did for decades with other controllers in the past. Although these days, they aren't supposed to fail - either not work at all, or go into a fail-safe float-only condition, but apparently the Wanderers are like those in the past that demand battery connections first *before* attaching a panel.
One gotcha' about this is if you are swapping out batteries, and forget to disconnect your panel, you may end up in that state with just a panel connected and no battery - and smoked controller.
I had a propensity to get this wrong myself a few times, so I kept a spare pwm controller on the shelf - or if for some reason the battery itself went open-circuit, I'd have a spare controller to put back into service asap.
