Repaired Samlex inverter not working at night

[ChemTutor]

Howdy, All!
We just started full-time RVing a few months ago and installed two solar panels along with all the peripheral gadgets that go into a solar system. Our 3000watt Samlex inverter was repaired (replaced fuses and a capacitor) and works like a champ when we are drawing amperage during daylight hours. However, as soon as the amperage/current stops at night, so does the juice to our outlets. Batteries are at 81%, so that's not the problem. The only difference from day to night is no current from the panels, of course. I am extremely ignorant of all this, so thought I would post the problem to the experts out there in the RV world. Is it something as simple as not having a switch flipped the right way??? Duh!
Thanks in advance for any help and advice.

[jrnymn7]

12.4v = 83% soc ??? On my four 6v bank, 12.4v = ~ 67% soc.

Are your batteries 6v gc-2's or 12v?

As others have asked, what are you using as far as power draw on these < 70% batts?

"However, as soon as the amperage/current stops at night, so does the juice to our outlets."

??? so your outlets are completely dead??? Does your inverter show a low voltage error?

[westend]

What do you have for a controller and monitor display?

With a somewhat sophisticated 12V system, it's good to have a "de-liar". That is a multimeter that can be used to measure various things in the system and separate any liars in the bunch. A meter will help you diagnose problems and give you a better grasp of how everything works together. Meters are inexpensive.

[time2roll]

Inverter should run fine down to at least 11.0 volts. Most run to 10.5 or 10.0 before they shut down. Any chance you have a low cut out voltage that was adjusted too high?

12.4 volts is not over discharged. Do verify the voltage right at the inverter.

Otherwise I recommend GoPower sine wave.

[BFL13]

A solar controller can't tell the SOC of a battery. It only knows what the solar is doing. There is probably nothing wrong with your controller as such.

To know what the battery has going in and out from everything, you need a monitor like the Trimetric with the shunt having everything across it, including the solar and the inverter, plus the usual things like furnace, lights , fans , etc.

Even then, deriving SOC from the information is an art rather than a science. You need to cross-check a couple of different things like AH count vs voltage to see if they match in order not to be misled by only one info source.

[ChemTutor]

Hello, All!
Thanks a million times over for all the responses! What a wonderful community! After some deliberation, we think we went overboard the first day of hook-up to the repaired inverter and ran everything we could in testing it. The batteries drained to nothing, and now we are trying to just let them recharge fully before we try putting much load on them at all. What we have discovered is that our charge controller is not very trustworthy. We have a bank of 6 batteries, and we have noticed lately (since draining the batteries) that the controller reads 43% one second and then 90% the next or vice-versa. What seems curious is how this controller knows we have 6 batteries and not just one. So, we are saving to buy a more informative and programmable controller.

Again, we are new to this stuff. I thank you all for the help. I didn't know our inverter was considered so big at 3000Watts! And, we do have the inverter connected directly to the batteries and then to the monitor and charge controller. If anyone out there disagrees with our guess that we just let the batteries drain too low, and have been continuing to put too much load on them, please let us know!

Maybe one day, we will be able to help someone with solar system issues…

[MrWizard]

3000 is a Big inverter
just what are you running from this during the day AND night

also keep i mine, that a few months ago was Mid Summer

and even on sunny days you are now getting less Solar Charge per day

so IF you have too much day use power the batteries are Not being fully recharged

and a Heavy enough load can cause a voltage Drop on the circuit

where is the inverter connected ? it should be connected directly to the batteries
also the output from the solar charge controller should be connected directly to the batteries

do your 12v lights work at night, water pump, heater etc..

[JiminDenver]

More info please.

Is there a possibility of the batteries being under charged or that there one bad apple in the bunch. It wouldn't show as easy with the solar holding it up.

[BFL13]

The voltage that counts is the loaded voltage it gets down to when you try to run something. That's when voltage drops below inverter low voltage shut off. However,

The fancy inverters like yours have other settings that might be at play here, and there can be things go wrong between inverter and its remote too based on some reports here on the forum. I don't have a clue about that side of things, sorry.

Maybe the repair crew messed up your settings. Or

Does anything work at night that should work from the inverter? If only the receptacles don't work but the microwave does work, then it's about the distribution of the 120v output from the inverter to the rig. Maybe it didn't get put back in right when it was out for repair.

[09FLSTC]

Have you talked with them? They do have pretty good customer support and I think that is the reason they are making a strong charge in the industry. I don't use one but will probably get one.

[ChemTutor]

Thanks for such a fast reply! Our remote monitor shows 12.4 volts, 0 amps and 83% battery charge. We have a bank of six batteries the inverter is connected to. Does any of this any difference is what's potentially wrong? We did use the manufacturer's suggestion of wire gauges.
Thanks again!

[BFL13]

After solar goes dark, the battery voltage goes down too not just the current from solar.

The inverter needs voltage from the battery to work and has a low voltage shut off. If your wires from inverter to battery are not fat enough for their lengths, or if you don't have enough battery to hold the voltage up with that inverter draw when the battery is starting out at less than full (which it acts more like full with the solar backing it up in the daytime) then you will go below that voltage shut off when trying to run big things off the inverter.