Victron 100/30 Only pulling 35 watts

[dmkjr]

Good evening. i have a MPPT 100/30 controller installed on my 5th wheel camper with a SmartShunt. It's the Solar Flex 400i package from Keystone.

I have added a Cerbo GX and I'm trying to utilize the system, replacing the stock inverter with an Ampvint 3000w inverter which allows me to run it in Battery Priority mode.

However, I think something may be wired wrong, or I don't completely understand the grounding requirements perhaps. The MPPT is not drawing much solar energy at all. I'm seeing 32-35 watts continuous from the controller, even when it was in Bulk mode. Voltage from is showing as 35.15v with 0.9-1a producing 35 watts. They are two 200 watt rated Future Solutions solar panels. It was sunny today, direct sunlight. Panels are wired in parallel.

I'm going to post some pretty bad pictures. I haven't cleaned up the wiring yet.

Any ideas on what could be going on?

Thank you!

 

[HRTKD]

I would think something is wrong with one of your panels or something in the wiring between the panels and the solar charge controller.

Check all the connectors to make sure they are not running hot or perhaps melted. A bad MC4 connector has been known to melt and cause poor solar production.

Disconnect the MC4 connectors coming out of the panels and use a multimeter to test each one individually.

Watch this video:

 

[StuartV]

I think your smart shunt is wired in wrong. Its showing your usage AND the solar production.

The shunt should be wired inbetwen your battery and inverter, but looks like its wired between your inverter and SCC instead. (I think).

 

[dmkjr]

I think your smart shunt is wired in wrong. Its showing your usage AND the solar production.

The shunt should be wired inbetwen your battery and inverter, but looks like its wired between your inverter and SCC instead. (I think).

Hmm, that may be the issue. The factory wired this, just trying to get it back to good. I will move that and report back.

 

[740GLE]

I think your smart shunt is wired in wrong. Its showing your usage AND the solar production.

The shunt should be wired inbetwen your battery and inverter, but looks like its wired between your inverter and SCC instead. (I think).

Solar production is coming from the SCC itself, when connected to VE network the Cerbo can talk to it, no second shunt is needed.

Is there a shore power charger as well? Looks like the shunt is showing a total of 197w into the battery.

I second double connecting all connections from the panels to the SCC. A bad connection can show good voltage at the SCC but the current is trash.

Can you post a graph of the SCC output wattage for the day?

 

[dmkjr]

Solar production is coming from the SCC itself, when connected to VE network the Cerbo can talk to it, no second shunt is needed.

Is there a shore power charger as well? Looks like the shunt is showing a total of 197w into the battery.

I second double connecting all connections from the panels to the SCC. A bad connection can show good voltage at the SCC but the current is trash.

Can you post a graph of the SCC output wattage for the day?

I did have to connect shore power because the batteries were down to 49% (SLA). Checking connections this afternoon and will check the shunt issue.

Not sure I follow the second shunt issue. I have a smartshunt in between the battery and the inverter but the SCC is connected directly to battery I believe, bypassing the shunt. Could that be the problem?

 

[mikefitz]

Smart shunt input connects to battery negative, everything else, all chargers and loads, connect to the output side of the shunt.

This would not solve the issue of a very low power input to the solar controller . Possible issues with panels or connections to the solar controller

 

[740GLE]

I did have to connect shore power because the batteries were down to 49% (SLA). Checking connections this afternoon and will check the shunt issue.

Not sure I follow the second shunt issue. I have a smartshunt in between the battery and the inverter but the SCC is connected directly to battery I believe, bypassing the shunt. Could that be the problem?

A smart shunt location is independent of how a SCC is able to push Watts (on a battery that’s low and needs the watts) both screen shots show the SCC is in bulk so she should be giving it all the beams! I’m thinking connection issue.

Did you use Wye connectors to parallel those panels? Might be able to disconnect that and just try one panel directly connected to the SCC.

 

[RoadTurtle]

Do you have a photo of the panels on the roof? And WTF is that wiring rats nest?

 

[HRTKD]

And WTF is that wiring rats nest?

That's your typical RV wiring closet. That one actually doesn't look bad. At least compared to mine.

 

[RoadTurtle]

That's your typical RV wiring closet. That one actually doesn't look bad. At least compared to mine.

I thought mine was bad, and it's looks a lot neater than that!

My wiring issues were a bit different, crimps were so bad, TWO terminals were at best a slip fit, a different one at least took a tug (pound or two) to pull it apart. Is it any wonder my 60a charger was only 23a to the battery? And that was AFTER I fixed the bad connectors I found.

 

[Browneye]

Winnebago wiring...LOL
The conduits are 120V romex. At least all the 12V fixtures and appliances have home-run grounds to a welded bus on the frame - lower right.

I've cleaned up a lot of this when everything got revamped with solar and LFP.

 

[RoadTurtle]

Your winnebago doesn't bother my OCD as much as the terminations showed earlier in the thread.

 

[dmkjr]

Your winnebago doesn't bother my OCD as much as the terminations showed earlier in the thread.

Listen Linda Most of what looks rough there (the loose wiring) is from the recently installed Victron monitors. Gerbo GX and GlobalLink 520. They will get cleaned up and the black cover will go back on. In terms of the connections, that's Keystone for you.

I did move the power from the "rats nest" and put it directly to the battery. Negative is on the downstream of the shunt at this point. Now, I was able to get 60watts at 6pm EST from the panels, so we may be on the right track. Will report again tomorrow once the sun comes back out.

 

[sunsurfer]

Did you use Wye connectors to parallel those panels? Might be able to disconnect that and just try one panel directly connected to the SCC.

I was just thinking perhaps there is no diode isolation between the parallel panels. Could one panel be going into the other? Worth a look if you run out of ideas

 

[dmkjr]

I believe I fixed all of the factory wiring today.

Took the bus bar’s that were built-in to the distribution box and pulled the main negative from the battery directly to the downstream side of the shunt. Also removed the ground they had wired to the downstream side of the shunt as well.

SCC is now tied into the bus bars from the distribution block and the Cerbo is reporting normally now, I believe. Will find out with sunshine tomorrow.

how much power does a typical 3000w inverter draw on idle? I’m looking at around 70w constantly.

 

[740GLE]

Ouch! That’s normal for the cheaper inverters. That’s almost two panels just to keep the inverter powder on.

How’s venting where the inverter is located? 70w could build up some good heat running 24/7.

 

[sunsurfer]

Ouch! That’s normal for the cheaper inverters. That’s almost two panels just to keep the inverter powder on.

How’s venting where the inverter is located? 70w could build up some good heat running 24/7.

I have an AIMS 4k 24v LF that pulls 92w idle. Its a pig but its powered everything I have thrown at it. Luckily it only comes on when its working a big load...well pump, air compressor, chopsaw...etc...