Solar system bust

[AndreandElisha]

We recently had 3 385 watt solar panels installed along with a victron multiplus 3000 watt inverter. Before, we had battery power for lights and used the generator for 110 power if not plugged in. Batteries held a decent charge and charged fairly quickly with the generator.
Now, when we have sun we can run basically everything in the RV except the AC. But as soon as the sun goes down, we have almost zero battery power. We can no longer charge the batteries with the generator, we have to actually run the RV engine! And we still have to run the generator if we want any kind of power. And I am talking 1 reading light. Everything else is completely shut off. Microwave unplugged, inverter off, converter unplugged, we don't even leave the water pump on.
We have a 2004 Georgetown XL 346 which has the chassis battery and 2 12v house batteries under the stairs. We would like to increase our house batteries but not sure where to put them. Plus, I don't feel that adding more batteries is going to fix the problem.

 

[flyboy013]

It sounds like the solar panels are doing a great running everything in the coach, but perhaps they are not charging the batteries with that solar power. Have you put a voltmeter on the batteries to get a reading while you have solar power? It also sounds like the generator isn't charging the batteries. Sounds like the batteries are not connected. Perhaps a shutoff switch at the battery?

 

[TJ&LadyDi]

It does sound like the solar panels are not charging the batteries. I would go back to the installer with the problem. I'm guessing something has not been configured correctly.

Another thought is how old are your batteries? Is it possible that they are bad and not holding a charge?

TJ

 

[Chuggs]

There could be lots of things going on. The quantity and type of batteries you have is truly the heart of an off grid system. How many aH of storage do you have? Did the installation manual for that 3000w inverter really recommend 2 twelve volt batteries? Were the charge parameters set properly? For example...you have enough solar to be pushing 80 amps or more. If not set up properly...this will cook your two batteries.

I would focus first on making sure you understand the inverter/Charger, and Solar Charge controller...how to adjust parameters for a specific battery type. Then...purchase some batteries designed for the demands of deep cycles with adequate storage to meet your needs for more than just overnight. I ran a test on my coach...I have eight 6v deep cycle golf cart type batteries. They can run the parasitic drains, misc router...and other items as well as our residential refrigerator for about 40 hours. That isn’t to the point of the batteries being dead...this is to the 50% point. Depending on battery chemistry, using more than this penalizes you with shortened battery life.

If you said you had 1000w inverter for charging tablets, and phone, and you ran led lights...two 12v batteries might be okay. Running a 3000w inverter...you must be doing more than phones with that. Fridge? Microwave? Coffee Maker? These can pull quite a bit of amperage. Something that you might not have considered is battery efficiency. Lead acid batteries are good at giving back the energy they stored at a 20hr rate. So, if you had a 100aH battery... over 20hours...of 5A drain. 5A at 12.6v would be 63 watts... Hmmm, so 63 isn’t close to 3000w. Let‘s say you have two of these batteries. 126w...getting closer, but still no where close to 3000w. Don’t worry...you’re not alone. Most of us are drawing more than the C/20 rate from our cells. The trade off comes with energy loss from Peukert effect. As you increase the rate of discharge...more and more energy is lost due to thermal loss ...thus due to the batteries internal resistance. So if you thought of getting 100ah out of the battery...it just won’t happen when your discharge rates are high. I have seen over 165Amps going to my 3000 watt inverter at times. What can you do? You have to spread it out over multiple batteries. Having more batteries is more than just giving you more aH of storage...it means spreading out the load so that each battery is discharged at a slower rate. At this slower rate...you have fewer aH of storage lost to heat energy.

If the previous replies are correct...and the batteries aren’t connected to your solar...well that’s a sign your installer isn’t very good at his job. To me, that is already evident...he sold you a system that is that large...and didn’t explain to you how poorly designed it was due to the fact that two batteries aren’t going to meet your needs. I also think the batteries could have been damaged, if they were connected, but not charged with the proper amperage. Lifeline AGMs and Lithium batteries are about the only ones capable of very high charging amperages. If you have flooded lead acid batteries...they will boil off at those high rates. 80A of charge would be more appropriate for 800aH worth of batteries.

That‘s a really nice solar panel array, and inverter....but they simply need more storage, and good quality storage.

 

[Jim]

We recently had 3 385 watt solar panels installed along with a victron multiplus 3000 watt inverter. Before, we had battery power for lights and used the generator for 110 power if not plugged in. Batteries held a decent charge and charged fairly quickly with the generator.
Now, when we have sun we can run basically everything in the RV except the AC. But as soon as the sun goes down, we have almost zero battery power.

I have a stupid question.

It seems everyone feels the solar panels are doing a great job running everything. But how do we know that the solar panels are doing the work? If the batteries are dead at the end of the day, maybe it's actually the batteries that are doing the work and the solar isn't getting to the batteries.

Like I said, probably a stupid question.

 

[TJ&LadyDi]

I have a stupid question.

It seems everyone feels the solar panels are doing a great job running everything. But how do we know that the solar panels are doing the work? If the batteries are dead at the end of the day, maybe it's actually the batteries that are doing the work and the solar isn't getting to the batteries.

Like I said, probably a stupid question.

There aren't any "stupid questions" on RVF @Jim; just questions that need answers. And, your question is actually a very good one. I'm hoping some of the solar gurus here can provide a relatively simple method of how to measure whether the solar panels are actually performing as designed.

TJ

 

[flyboy013]

You stated that you “can no longer charge the batteries with the generator, we have to actually run the RV engine! And we still have to run the generator if we want any kind of power.”

Sound like the generator is outputting 120V which is feeding the transfer switch and then 120V circuits including the inverter. I assume you can operate 12V devices (lights, etc) with the generator running. If so, the charger is working. If not then there is a cut off switch or fuse limiting the invert in providing 12V to the coach.
I’m assuming your batteries are basically dead and the only way to get power is via solar, generator, or as you have stated the engine alternator (which would also mean that the charge bridge is engaged providing the alternator power to the coach systems.

You really need to get a voltage reading at you coach batteries, ideally when you have power going to them (via solar/charge controller, or generator) AND without power feeding the batteries. I’m guessing that the voltages will be the same, and you will find that the generated power isn’t feeding the batteries. Perhaps a blown inline fuses, a switch between the batteries and inverter/solar controller is turned off, or a wire is disconnected.

You need to trace the power. Once we know what the voltage is at the batteries (with solar or generator running), we can help isolate where the disconnect/issue exists.

BTW - I’m no solar or power expert, but I am an engineer and my suggestion are based on occupational troubleshooting techniques. Others on this forum have much more expertise with solar systems.

 

[Chuggs]

There is a quick way, and a more detailed way to see if solar is working.

Lead acid batteries...as an example...if not being charged...are approx. 12.6v. If you have a voltage reading from the house batteries...if they say 12.6 or less...solar isn't doing anything. If you see a higher voltage, something other than the batteries are at play. The solar charge controller will usually do a three stage charge...BULK, ABSORB, and FLOAT. I have my controller set to Bulk Charge at 90A (Thats for 928aH bank)...it will push up to that many amps until my absorb voltage is reached, then switches to constant voltage of 14.51v. It holds this until the amperage tapers off to the tail current draw...then drops down to 13.43v to float, until sundown. So I can usually guess what solar is doing just by comparing the voltage reading of the batteries to what I expect my charge controller to do.

Now, the more accurate method is to read the controllers display. It should tell you how many watts are being output in real time, and I highly recommend a shunt based battery monitor. The battery monitor can display at a glance how many amps are either going IN or OUT...and what the battery charge state is (SOC) expressed in percentage of full.

It only takes about 150watts to maintain float voltage on my coach...so, if I see the wattage output is up around 900 or more...I know my wife probably has something in the microwave.

It takes time to learn the nuances of your system. There isn’t an overnight...know everything. It is a series of puzzling things, that you endeavor to explain logically. The more you convert these puzzling moments into eureka events....the more you will understand solar.

So, don't get frustrated....these puzzles are part of the growth of your knowledge base.

 

[TJ&LadyDi]

Good explanation, @Chuggs; thanks for helping fill in one of the many gaps in my knowledge base.

TJ

 

[AndreandElisha]

You stated that you “can no longer charge the batteries with the generator, we have to actually run the RV engine! And we still have to run the generator if we want any kind of power.”

Sound like the generator is outputting 120V which is feeding the transfer switch and then 120V circuits including the inverter. I assume you can operate 12V devices (lights, etc) with the generator running. If so, the charger is working. If not then there is a cut off switch or fuse limiting the invert in providing 12V to the coach.
I’m assuming your batteries are basically dead and the only way to get power is via solar, generator, or as you have stated the engine alternator (which would also mean that the charge bridge is engaged providing the alternator power to the coach systems.

You really need to get a voltage reading at you coach batteries, ideally when you have power going to them (via solar/charge controller, or generator) AND without power feeding the batteries. I’m guessing that the voltages will be the same, and you will find that the generated power isn’t feeding the batteries. Perhaps a blown inline fuses, a switch between the batteries and inverter/solar controller is turned off, or a wire is disconnected.

You need to trace the power. Once we know what the voltage is at the batteries (with solar or generator running), we can help isolate where the disconnect/issue exists.

BTW - I’m no solar or power expert, but I am an engineer and my suggestion are based on occupational troubleshooting techniques. Others on this forum have much more expertise with solar systems.

Our solar installer is now 1200 miles away but is helping us troubleshoot by chat. Unfortunately neither of us are electrically inclined.
We figured out how to charge our batteries with the generator. We have a converter that we were told to leave unplugged unless plugged into shore power. However, once the converter was plugged in, we were able to charge the batteries with the generator up to about 13.3.

 

[AndreandElisha]

Our solar installer is now 1200 miles away but is helping us troubleshoot by chat. Unfortunately neither of us are electrically inclined.
We figured out how to charge our batteries with the generator. We have a converter that we were told to leave unplugged unless plugged into shore power. However, once the converter was plugged in, we were able to charge the batteries with the generator up to about 13.3. So, while not ideal, we are figuring out ways to not feel like we are tent camping with flashlights at night...lol.
We are also looking for ways to expand our battery bank. Our current set up is under the stairs and can only fit 2 31's and the chassis battery. We are looking at moving it to a basement compartment next to the stairs.
We bought the Victron off of Craigslist, as it was a "really good deal" and it just happened to be a multiplus 3000. We are quickly learning that we have soooo much to learn!

 

[flyboy013]

Why did the installer have you keep the charger unplugged while not on shore power? I would think that it would be plugged in all the time so that when you have shore/generator power, it will immediately do its job.

I'm still concerned about the statement: "when we have sun we can run basically everything in the RV except the AC. But as soon as the sun goes down, we have almost zero battery power." This would imply that the solar system isn't charging the batteries either.

I understand that you are not electrically inclined, but you're going to have to learn some basic electrical skills, such as how to measure voltage with a multimeter. Its not too difficult and there are lots of YouTube videos to guide you through it. If you don't already have one, you can get a basic one for as little as $10.

Once you have a multimeter, you can determine what voltage the solar system is outputting and what voltage the batteries are seeing. If they aren't the same, then there is an electrical disconnect between the two. If they are the same (or close), then the problem may be the batteries are not holding a charge or you're using more power than the batteries are designed to provide.

 

[Neal]

We recently had 3 385 watt solar panels installed along with a victron multiplus 3000 watt inverter. Before, we had battery power for lights and used the generator for 110 power if not plugged in. Batteries held a decent charge and charged fairly quickly with the generator.
Now, when we have sun we can run basically everything in the RV except the AC. But as soon as the sun goes down, we have almost zero battery power. We can no longer charge the batteries with the generator, we have to actually run the RV engine! And we still have to run the generator if we want any kind of power. And I am talking 1 reading light. Everything else is completely shut off. Microwave unplugged, inverter off, converter unplugged, we don't even leave the water pump on.
We have a 2004 Georgetown XL 346 which has the chassis battery and 2 12v house batteries under the stairs. We would like to increase our house batteries but not sure where to put them. Plus, I don't feel that adding more batteries is going to fix the problem.

Can you attach pictures of your solar controller area so we can see the wiring setup? Did they install cutoff switches that may be OFF by chance? On mine, as designed by @Chuggs there are two cutoff switches, one between the panels and the controller, one between the controller and the battery bank. If either of these are OFF you're not charging your batteries. It's odd that while getting solar (PV) you're able to do things but the batteries aren't supplying when PV is gone. It seems the circuit between controller and batteries is disconnected. Maybe also include a picture of your battery bay.

 

[AndreandElisha]

Why did the installer have you keep the charger unplugged while not on shore power? I would think that it would be plugged in all the time so that when you have shore/generator power, it will immediately do its job.

I'm still concerned about the statement: "when we have sun we can run basically everything in the RV except the AC. But as soon as the sun goes down, we have almost zero battery power." This would imply that the solar system isn't charging the batteries either.

I understand that you are not electrically inclined, but you're going to have to learn some basic electrical skills, such as how to measure voltage with a multimeter. Its not too difficult and there are lots of YouTube videos to guide you through it. If you don't already have one, you can get a basic one for as little as $10.

Once you have a multimeter, you can determine what voltage the solar system is outputting and what voltage the batteries are seeing. If they aren't the same, then there is an electrical disconnect between the two. If they are the same (or close), then the problem may be the batteries are not holding a charge or you're using more power than the batteries are designed to provide.

He said to keep the converter unplugged so we didn't cause a loop effect. ?? And we are picking up a voltmeter tomorrow and see if we can try to pinpoint what's going on.

 

[Neal]

Here is a voltmeter I use I got from Amazon I really like.

https://www.amazon.com/gp/product/B000O3LUEI/?tag=rvf01-20

Just know the limits of the voltmeter as I tried testing the current coming from the solar with it and kept blowing the fuse. The voltmeter has a 10A limit and you can get some crazy good power coming off those panels so be aware of what you're testing and the current that it can be flowing in what you choose. A clamp meter is another good option.

https://www.amazon.com/dp/B07Z3988K3/?tag=rvf01-20

@Chuggs can probably steer you better on what to use based on what you're testing than I can. I have both a voltmeter and clamp meter.

 

[Chuggs]

Ahhh....Interesting, disconnect the converter to avoid a LOOP. That has told us a lot...

It appears they have installed your Solar/Inverter system...not as a Solar System, per se...but as a Solar Generator. I'm guessing here...but I have seen this used, generally as a short cut when adding an Inverter.

The batteries power the inverter, and the coaches existing shore cord is plugged into a receptacle on the output of the inverter. You are told to disconnect the converter because the inverter is taking 12vdc from the battery, then changing it to 120vac...your power cord takes this...thinking it is shore power...and converts it back to 12vdc to charge your batteries. The converter and inverter are shy of having 100% efficiency...so all you do is loose power by looping the energy thru two devices that have limited efficiency. It is a way to avoid using an automatic transfer switch, and you have probably avoided a dedicated inverter sub panel, your inverter doesn't have an AC input for shore power pass thru... These additional features all make the system behave without a lot of operator input.

I think @Neal has the right idea. Your solar should be wired to the batteries. It is code to have current protection on the wiring...and for maintenance switches to isolate the system. Look for fuses, switches, or Marine DC breaker switches. If one of these tripped...or was turned off...your solar system is inert. When turning the system ON...it is best practice to begin with both the Photovoltaic side, and battery side turned OFF. You then connect the battery side. This gives your solar controller power to turn it's brains on...so to speak. After that...turn on the Photovoltaic side...and it will condition that power accordingly to charge the batteries. If you are disconnecting the system...do the reverse. Turn off PV first...then battery.

You are working with a system that uses a work around. It is basically allowing you to use the Inverter...on all of your houses AC wiring...by pluging in the original wiring into the inverter vs a shore receptacle. If you unplug from the inverter..turn your converter back on...and fire up the generator or plug back j to a shore power receptacle... you should be able to recharge the batteries.

So, there is going to be a lot of manipulation involved each time you want to use the shore power or generator power vs off grid using solar&battery to power thru the inverter with the converter disabled.

It now makes more sense...the only way you can charge your battery is thru the alternator with the engine running...and solar either has not been sufficient or has tripped and is not charging at all.

 

[AndreandElisha]

Can you attach pictures of your solar controller area so we can see the wiring setup? Did they install cutoff switches that may be OFF by chance? On mine, as designed by @Chuggs there are two cutoff switches, one between the panels and the controller, one between the controller and the battery bank. If either of these are OFF you're not charging your batteries. It's odd that while getting solar (PV) you're able to do things but the batteries aren't supplying when PV is gone. It seems the circuit between controller and batteries is disconnected. Maybe also include a picture of your battery bay.

 

[AndreandElisha]

Ahhh....Interesting, disconnect the converter to avoid a LOOP. That has told us a lot...

It appears they have installed your Solar system...not as a Solare System, per se...but as a Solar Generator. I'm guessing here...but I have seen this used, generally as a short cut when adding an Inverter.

The batteries power the inverter, and the coaches existing shore cord is plugged into a receptacle on the output of the inverter. You are told to disconnect the converter because the inverter is taking 12vdc from the battery, then changing it to 120vac...your power cord takes this...thinking it is shore power...and converts it back to 12vdc to charge your batteries. The converter and inverter are shy of having 100% efficiency...so all you do is loose power by looping the energy thru two devices that have limited efficiency. It is a way to avoid using an automatic transfer switch, and you have probably avoided a dedicated inverter sub panel, your inverter doesn't have an AC input for shore power pass thru... These features all make the system behave without a lot of operator input.

I think neal has the right idea. Your solar should be wired to the batteries. It is code to have current protection on the wiring...and for maintenance switches to isolate the system. Look for fuses, or Marine DC breaker switches. If one of these tripped...or was turned off...your solar system is inert. When turning the system ON...it is best practice to begin with both the Photovoltaic side, and battery side turned OFF. You then connect the battery side. This gives your solar controller power to turn it's brains on...so to speak. After that...turn on the Photovoltaic side...and it will condition that power accordingly to charge the batteries. If you are disconnecting the system...do the reverse. Turn off PV first...then battery.

You are working with a system that uses a work around. It is basically allowing g you to use the Inverter...on all of your houses AC wiring...by pluging in the original wiring...the the inverter vs the shore receptacle. If you unplug from the inverter...turn your converter back on...and fire up the generator, you should be able to recharge the batteries. So, there is going to be a lot of manipulation involved each time you want to use the generator vs shore power vs off grid using solar&battery to power thru the inverter with the converter disabled.

It now makes more sense...the only way you can charge your battery is thru the alternator with the engine running...and solar either has not been sufficient or has tripped and is not charging at all.

Yes, we have to unplug the solar when we plug in to shore power. We had to have another guy install the disconnect for the solar panels so Andre didn't have to climb on the roof and physically unplug the panels to do something. How do we go about getting a more efficient sysyem?

 

[Chuggs]

Well...the solar should have disconnects...but you should only have to disconnect the solar If removing the batteries for maintenance. The solar system should be wired to the batteries...and operate regardless of how you are managing the rest of the rv's electrical circuitry. It is a battery charging device...it should always remain connected...and it will do it's job when the sun hits the panels.

The Inverter setup is a work around...and it works, and has saved you money...but requires additional jockeying by switching plugs and disabling converter, etc...

There are a couple of ways to skip all that...but they require an upgrade to your scheme. The output from the inverter gets fed to a new sub panel and you no longer plug the shore cord into an inverter powered receptacle. The circuits you plan to use off grid get moved from your main panel to the sub panel. The converter remains on the original main panel...it doesn't recieve power from the inverter...so you do not have to disconnect. To save energy, when connected to shore power...you can add an auto transfer switch that automatically connects to shore power if present...and if not...connects to the inverter output. The transfer switch powers the inverter subpanel.

In lieu of the auto transfer switch...you could remove the inverter and converter you have...and replace them with an all-in-one unit. They have the transfer switch and converter built-in. Magnum MS2812 or MSH3012...or a Victron Multiplus. These are more expensive systems but have all those automatic features that work without you having to manipulate anything.

 

[Kevin D Pem]

Our solar installer is now 1200 miles away but is helping us troubleshoot by chat. Unfortunately neither of us are electrically inclined.
We figured out how to charge our batteries with the generator. We have a converter that we were told to leave unplugged unless plugged into shore power. However, once the converter was plugged in, we were able to charge the batteries with the generator up to about 13.3.

Just one big point on the converter. If you plug in the converter when under the inverter power you will have established a closed loop. This means the batteries will drain trying to charge themselves.

I run a circuit( if nothing but an extention cord to the converter from the generator or grid power post to charge batteries. Sounds like the installer did half a job. Make sure the inverter is wired to the house where the generator, or land line will not be in the circuit at the same time or the inverter will be toast, unless it is a UPS type system.

My intent is to have a supply line from generator to charge the battery bank using converter when needed. I never hook the 115vac house line to the converter after I have installed a inverter. Because I am old school, there is nothing to program as transfer switches are not in my system. I plug the house plug into outlets I have installed in the location of the cord. I can then choose what power source I will use.

I will go further if you desire more input and options, but It will be hard if you are listening to many people so I will sit in the background till you get your answer or you ask me.

Now on to solar:

Get your multi meter out.
measure voltage on the controller at the battery posts.( this is the solar controller connections )
No voltage means that your system was never connected to the battery bank or the DC breaker that should have been installed close to the
battery has tripped or is bad.
Measure voltage on controller at the panel posts.
During the day this will be the MPP (Maximum power point) voltage of the panel. If the voltage is Open circuit voltage of the panel the controller is not working. If the voltage is close to bank voltage then the controller has not woke up, or is not working. if the voltage is at MPP the controller is charging the battery bank.

If the system was installed right then you will find breakers or switches to turn off both panels and batteries from the controller. It is important that the batteries are switched on and the controller is getting battery voltage before the panels are connected/switched on. The controller can fail if the panel wiring is turned on first.