Solar problems

[loper]

First off, this is NOT a complaint against Redarc, they have been very helpful so far.

I have a Redarc BCDC1240 charger in my van.
I am running two 100ah 12V AGM batteries.
For the last year I've been just using the vehicle charging aspect of the Redarc box, I didn't have a solar panel. It has been great as an isolator/charger.
I just got a Dokio 220 watt monochrystaline folding solar panel. The panel came with a little PWM controller. Running through this controller I get pretty good results charging the batteries (went from 12.0V to 13.0V in 4 hours).

Here's where it gets sticky:
I plugged the panel into the Redarc box (direct from the panel, not through the PWM controller) in order to take advantage of the MPPT controller built into the Redarc box. Immediate fault, sometime under voltage, sometimes over voltage.
I called Redarc tech support, and checked voltages at every connection, from the panel, in and out of the box, everything checks out, the box must be bad, and Redarc sent me a new box.
Connected the new box and started testing. Got a lot of fault codes (both under and over voltage) using power from either the vehicle or from the solar panel. The solar indicator does not light up when connected to the solar panel.
Spent about another hour on the phone with tech support, checked voltage everywhere, and everything looks good, except it doesn't show solar when connected to the solar panel, and doesn't charge from solar. I ran out of daylight before we could solve it, and I'm waiting till Monday (in Australia) to call back to tech support when I have plenty of sunlight, to try again.

I'm stumped, and the Redarc tech guys are stumped. I'm thinking either I got another bad box (seems unlikely), or for some reason the solar panel just won't talk to the Redarc box (the specs call for 9-32 volts unregulated, the panel has been putting out between 18 and 21 volts, depending on the sun). Everything should be working, but it just ain't.

Any ideas what I'm missing?

 

[Dave Snyder]

I don't have any experience with solar but I would start to suspect that somehow the panel isn't compatible with the Redarc controller. If you have the option try hooking up a different panel and see what happens. Just my two cents.

 

[grubworm]

all the solar panels do is output a voltage, so there isnt anything to be compatible with. if the panels operate fine with the pwm controller, then the panels are good and the controller is fine. the redarc operates fine with charging from the altenator, but apparently not with the panels.

sounds like there is a conflict inside the redarc. what happens if you disconnect the altenator from the circuit and run just solar thru the redarc? make sure you are +/- hooked up right. from what you have stated, everything seems fine until solar is hooked to the redarc. not sure exactly how the redarc is made, but more than likely there a microcontroller that will read the input voltage from the solar panel and if the voltage is within a certain range, then that voltage will be allowed to go to the battery.
not sure why you would get under and over voltage faults. i can see undervoltage if there is a short somewhere, but over voltage?
id be curious to see how the redarc works with only solar hooked up.

 

[loper]

all the solar panels do is output a voltage, so there isnt anything to be compatible with. if the panels operate fine with the pwm controller, then the panels are good and the controller is fine. the redarc operates fine with charging from the altenator, but apparently not with the panels.

sounds like there is a conflict inside the redarc. what happens if you disconnect the altenator from the circuit and run just solar thru the redarc? make sure you are +/- hooked up right. from what you have stated, everything seems fine until solar is hooked to the redarc. not sure exactly how the redarc is made, but more than likely there a microcontroller that will read the input voltage from the solar panel and if the voltage is within a certain range, then that voltage will be allowed to go to the battery.
not sure why you would get under and over voltage faults. i can see undervoltage if there is a short somewhere, but over voltage?
id be curious to see how the redarc works with only solar hooked up.

Actually tried that, taking the alternator out of the loop. Engine not running, circut breaker between the engine battery and the Redarc box open, plug in the panel. Faulted out, over voltage. Unplugged the panel, reset the box, plugged the panel in again. The box indicated "vehicle" input, boost charge, but was only producing 12.7V out to the batteries. I checked the panel and it was producing 20.8V at that time.

The specs on the box are 9V to 32V unregulated solar input. Every time I've tried this I've had between 18V to 21V coming from the panel (depending on the sun).

The box has never indicated "solar" input.

It all looks like the box is bad, but two bad boxes from a quality company seems unlikely.

The panel isn't top dollar. 220 watt Dokio off Amazon. I have seen some forum posts saying the Dokio panels don't work well with MPPT controllers. That made me think it was more of a panel problem. But then again, it works great with the cheap controller that came with it.

I think I'm just going to run the Redarc for alternator charging, and use the cheap PWM box for solar. Ain't what I wanted to do, but it will work that way.

 

[kunstmilch]

Actually tried that, taking the alternator out of the loop. Engine not running, circut breaker between the engine battery and the Redarc box open, plug in the panel. Faulted out, over voltage. Unplugged the panel, reset the box, plugged the panel in again. The box indicated "vehicle" input, boost charge, but was only producing 12.7V out to the batteries. I checked the panel and it was producing 20.8V at that time.

The specs on the box are 9V to 32V unregulated solar input. Every time I've tried this I've had between 18V to 21V coming from the panel (depending on the sun).

The box has never indicated "solar" input.

It all looks like the box is bad, but two bad boxes from a quality company seems unlikely.

The panel isn't top dollar. 220 watt Dokio off Amazon. I have seen some forum posts saying the Dokio panels don't work well with MPPT controllers. That made me think it was more of a panel problem. But then again, it works great with the cheap controller that came with it.

I think I'm just going to run the Redarc for alternator charging, and use the cheap PWM box for solar. Ain't what I wanted to do, but it will work that way.

Doesn't matter that the panel is cheap, it is working. Like it has been suggested, check all the wires, make sure they are all correct (im sure you have already but do it again) take photos of your connections and see them all to redarc. Possible they just sent the unit back? left hand not talking to right hand?

 

[grubworm]

The panel isn't top dollar. 220 watt Dokio off Amazon. I have seen some forum posts saying the Dokio panels don't work well with MPPT controllers. That made me think it was more of a panel problem. But then again, it works great with the cheap controller that came with it.

I think I'm just going to run the Redarc for alternator charging, and use the cheap PWM box for solar. Ain't what I wanted to do, but it will work that way.

that is an odd problem.
you spent a good chunk on the Redarc and it is nice to have charging from both panels and altenator...so maybe buy a small 50w renogy panel off amazon for $60 and see how it works. if it works well with that panel, then you know the Dokio brand panels you got are bad and all you need are better panels. besides...Dokio sounds too much like "Dookie", so can you really trust a name brand like that...?

 

[El-Dracho]

I am not an expert, but since I was interested and curious I just looked at the connection diagram in the manual online and found something interesting in it, maybe that solves the problem?

It says that depending on whether the alternator or a solar module is used as the charging source, the cable "charging source" must be connected differently and if both, so solar and alternator is connected, an additional changeover relay must be used for this connection. This has somehow to do with the fact that the blue cable is permanently monitored and the machine thus knows from where to charge, right?

DC Chargers and Isolators Wiring Guides

Need help to install or troubleshoot your REDARC DC Charger or Battery Isolator? View the range of helpful articles here.

www.redarc.com.au

This is exactly what I believe is also described here on the Redarc website

REDARC : Automotive Electronics, DC Charging & Brake Control

Want to buy 12v power, dc-dc overlanding gear or market leading brake controller? REDARC Electronics are the premium RV and accessory power manufacturer.

www.redarc.com.au

Could this be the answer? On the other hand, the product description reads as if you can just connect both to the device and it will do the switching. Maybe you could ask that at your next call with Down Under?

Good luck!

 

[grubworm]

It says that depending on whether the alternator or a solar module is used as the charging source, the cable "charging source" must be connected differently and if both, so solar and alternator is connected, an additional changeover relay must be used for this connection. This has somehow to do with the fact that the blue cable is permanently monitored and the machine thus knows from where to charge, right?

good catch, Bjoern
that could very well be the issue. if it needs a changeover relay and there isnt one, then without the relay to isolate one of the inputs, it might be wired in series where the altenator and the panel are inputting at the same time and giving the "over voltage" fault. might not be the problem, but it certainly would make sense

 

[loper]

This is really interesting. My Redarc box is BCDC1240D. I think the "D" on the end indicates some sort of change, because the manual that came with it has an entirely different wiring diagram (attached).

The instructions that came with the BCDC1240D show the red wire to vehicle power, black to ground, brown to aux batteries, and yellow to solar panel. No mention of a charging relay. It says the box takes all the inputs and sorts it out internally.

The blue, orange, and green wires are light gauge wires used to determine the charging profile and trigger "smart" alternators.

I will definitely ask the Redarc tech guys about this when I call tomorrow.

I'm going to try another name brand panel also, just to make sure it isn't a panel thing.

Thanks for the input, this might lead to a solution.

 

[loper]

Doesn't matter that the panel is cheap, it is working. Like it has been suggested, check all the wires, make sure they are all correct (im sure you have already but do it again) take photos of your connections and see them all to redarc. Possible they just sent the unit back? left hand not talking to right hand?

I have returned stuff, and got the same thing back in the past, so yeah that's a valid question. In this case, however, I still have the original box, they sent me a new one and said we'd sort out the return later. Really good customer support.

And yeah, I've checked and re-checked all the wiring against the diagram, all the terminals, the circut breaker (open and closed), the buss bars, voltage drop along all the wires, and all the voltages at the wires where they go into the box (to eliminate variables). And I did it again twice with tech support on the phone.

This is a thoroughly tested wiring job, I can tell ya!

 

[loper]

Well, I talked to the Redarc tech guys again, and the best they can come up with is try a different panel. Don't have another panel right now, but That seems to be the only thing left.

I got an ammeter and checked the amps coming out of the panel, and they are all over the place from 1.1 to 6.3, really erratic. The tech guys said that shouldn't be an issue, the Redarc box will take 1 amp and make the best of it.

I asked about the difference in the wiring diagram that El Dracho posted, they say that is for the previous generation BCDC which did NOT automatically switch between solar and vehicle power.

So, no answer unless I get another panel and get different results. Oh well. The panel works through the PWM controller, so I hard wired it in and I'll just use it for now.

 

[kunstmilch]

Well, I talked to the Redarc tech guys again, and the best they can come up with is try a different panel. Don't have another panel right now, but That seems to be the only thing left.

I got an ammeter and checked the amps coming out of the panel, and they are all over the place from 1.1 to 6.3, really erratic. The tech guys said that shouldn't be an issue, the Redarc box will take 1 amp and make the best of it.

I asked about the difference in the wiring diagram that El Dracho posted, they say that is for the previous generation BCDC which did NOT automatically switch between solar and vehicle power.

So, no answer unless I get another panel and get different results. Oh well. The panel works through the PWM controller, so I hard wired it in and I'll just use it for now.

gremlins

 

[Viking1204]

@loper make sure you have a good ground. When I first installed my Redarc DC-DC charger I too had issues. Thought the unit was bad but luckily I was at Expo East and one of the Redarc techs assisted me and when he noticed my ground was to the metal wheel well of my truck he insisted my issue was ground related and sure enough it was. Drilled a hole in the frame and ground it to the frame and everything started working perfectly.

 

[loper]

@loper make sure you have a good ground. When I first installed my Redarc DC-DC charger I too had issues. Thought the unit was bad but luckily I was at Expo East and one of the Redarc techs assisted me and when he noticed my ground was to the metal wheel well of my truck he insisted my issue was ground related and sure enough it was. Drilled a hole in the frame and ground it to the frame and everything started working perfectly.

One of the first things I learned about electrical problems is "it's always a bad ground". That's always a good question.

With that in mind, my ground is a heavy (Blue seas 200 amp rated) buss bar connected directly to the vehicle battery with 2AWG OFC cable. The Redarc box, aux batteries, and solar panel input all connect to the buss bar, with good solid connections.

 

[grubworm]

One of the first things I learned about electrical problems is "it's always a bad ground".

i think if you learned to be a little bit more "negative", you wouldnt be having these problems...

 

[cookiedough]

As I work on my battery box, I come across this thread - any resolution? I'm using Victron but the concept should be the same. Cold panel over-volting in series with the alternator?

 

[loper]

As I work on my battery box, I come across this thread - any resolution? I'm using Victron but the concept should be the same. Cold panel over-volting in series with the alternator?

I don't know what that means. NOT being a smart ass, I just don't know enough about solar.
I have tried without the engine running (eliminate the alternator as a factor) and it still codes out.
I tried a different panel with the same basic results, so I have given up on getting solar to run through this Redarc box.
Either panel works well through a PWM controller, so that's what I'm using.

 

[Patman]

When you hook up the solar with the MPPT attached, which wire do you hook it to? Yellow, or to the red battery?

If its to the yellow wire and it works, then the redarc internal regulator is faulty or incompatible (which would be odd).

Where is the solar panel grounded to?

You may have answered these Q's already and I missed it.

 

[loper]

Patman,
Yeah, I answered it, but it's buried up in the thread.
I have the solar input into the yellow wire, per the wiring diagram ( the PWM controller is wired separately, direct to the batteries).
The solar ground is a buss bar connected to the ground terminal of the starter battery with 2 awg OFC cable. All of the stuff in the rear of the van grounds through that buss bar, including the camping batteries.

 

[cookiedough]

I don't know what that means. NOT being a smart ass, I just don't know enough about solar.
I have tried without the engine running (eliminate the alternator as a factor) and it still codes out.
I tried a different panel with the same basic results, so I have given up on getting solar to run through this Redarc box.
Either panel works well through a PWM controller, so that's what I'm using.

No offense taken - I was just wondering if you kept with the PWM controller or Redarc found a solution.

I put together a battery box for my refrigerator, I have a cross country road trip planned, didn't like running it off the inverter/plug in the back of my tacoma, kept forgetting to switch it back on after stopping to eat or gas up.

The next item will be connecting it with the SCC, right now the plan is charge it up at a site that has electric overnight.

edit: perhaps you were talking about the cold panel - in grubworm's post above it was mentioned the series voltage, solar panels put out higher voltage when they are cold, I saw Idaho in your signature, so assumed a low temperature.