Need help troubleshooting my solar system

[xwildtigerx]

I need help figuring out what is the problem with my solar system..
What I have:
- 4 x 100w renogy solar panel, wired in series
- victron smart solar 100/50
- 2x 6v 305Ah battery, wired in series to make 12v 305Ah battery bank
- 1500w samlex inverter

Daily use:
- 4 led lights
- 1 roof fan
- 2x 12v little fan
- dometic fridge
- portable toilet fan
- and sometimes charging laptop or vacuum cleaner

the system was running smooth and always reach float stage every single day until I added battery monitor and fridge. I was just never reached float stage anymore on day full on sunlight. So somene suggested to maybe un-plugged the battery monitor, which I did. It went back normal for a day. After that it is still not reaching float stage. I unplugged all the load beside toilet fan. I did check voltage on each panel theyre 20.2 v each. Battery is about 12.8v at midnight which is it is about full.. but why did solar charger doesnt recognize it..
I have been trying to get in touch with the dealer, they couldnt see what is going on with it.. asked somebody else said I need another 280w panel...
please help!!

[SunEagle]

Hello xwildtigerx and welcome to Solar Panel Talk

That battery should safely provide about 900 watt hours a day (12v x 305Ah = 3660wh x .25 = 915Wh)

While you listed your loads you did not provide the total watt hours they would use in a day. IMO adding that fridge probably drained the battery system below 50% which would make it very hard to get back to 100% with only 400 watt of panels.

You could increase your panel wattage but IMO the weak link is your battery system being too small for your daily loads.

[Sunking]

Relax there is nothing wrong with your equipment, it is doing exactly what it was designed to do. Not sure what you think is wrong, but there is nothing wrong other that operator error. You do not have enough panel wattage or battery. So relax there is nothing wrong.

[xwildtigerx]

SunEagle , i did calculate my watt hours daily it is about 700 a day. Like I said it reached float stage before i added fridge, and now I remove all load beside one little fan for few days, still not reaching float stage..

Sunking , so even if the charge controller never reached float stage thats ok?

[SunEagle]

SunEagle , i did calculate my watt hours daily it is about 700 a day. Like I said it reached float stage before i added fridge, and now I remove all load beside one little fan for few days, still not reaching float stage..

Sunking , so even if the charge controller never reached float stage thats ok?

If your daily discharge is much less then your "recharge" amount you can reach float stage. My guess is that by adding the fridge your panels can't replace 100% of what you took out of the battery overnight.

Remember batteries slowly die and will not provide 100% Ah nameplate power after a while. If you discharge them more than 50% you severely can cut their life even more and reduce the "100%" level below nameplate.

[littleharbor]

As to adding a 280 watt panel, DON"T. Depending on whether it is a 60 cell, or a 72 cell panel the voltage will be either too low to mix your other array with. If your array is wired , as you say all in series. your input voltage is too high to mix in any 280 watt panel. If you're wired 2s2p for a 24 volt nominal input only a 72 cell 280 watt panel would work in parallel Starting with 12 volt panels has limited your options and to add more of these 100 watt panels is going to cost more per watt than it should but at this point if you did get 2 more of these panels you could wire them 3s2p without having to add fusing and a combiner box.

[ewarnerusa]

An RV fridge run on electric is about a 300 watt load. At least our Norcold is. That is a lot of electric load for an RV battery system, use propane instead. As indicated, adding the fridge on electric has drained and possibly damaged the batteries.

[Sunking]

SunEagle , i did calculate my watt hours daily it is about 700 a day. Like I said it reached float stage before i added fridge, and now I remove all load beside one little fan for few days, still not reaching float stage..

Sunking , so even if the charge controller never reached float stage thats ok?

Absolutely. It means your system is now grossly undersized and killing your battery from neglect and abuse.

[xwildtigerx]

If I have to add 2 more panels, I dont think it will fit on the roof. One 100w might fit.
ewarnerusa based on dometic website the fridge rated at 5.5 amp which is about 66watts..
is buying a generator to help charging the battery an option if I cant add more panel to the roof?

[Sunking]

You have an off-grid solar system and do not have a generator? How to you expect to get through winter, cloudy spells, make up for shortages, and perform preventative maintenance?

[xwildtigerx]

We wont be in the states that will have snow. The only purpose we moved to a camper van. And also I did know anything about solar, the only knowledge I have is physics. Someone supposed to take care of the system for me but he backed up the last minute and I couldnt afford to hire installer...
Btw, any suggestion for the generator?

[SunEagle]

We wont be in the states that will have snow. The only purpose we moved to a camper van. And also I did know anything about solar, the only knowledge I have is physics. Someone supposed to take care of the system for me but he backed up the last minute and I couldnt afford to hire installer...
Btw, any suggestion for the generator?

Probably a quite inverter style type. Maybe a 2000w Yamaha or Honda come to mind. Remember you still need a good battery charger for deep cycle batteries. Not the cheap type you get for your car battery.

[ewarnerusa]

If I have to add 2 more panels, I dont think it will fit on the roof. One 100w might fit.
ewarnerusa based on dometic website the fridge rated at 5.5 amp which is about 66watts..
is buying a generator to help charging the battery an option if I cant add more panel to the roof?

It should say on a sticker on the unit itself what its AC electric rating is. Our Norcold is a typical RV type unit with freezer and it is rated at 300 watts. I confirm this with a kill-a-watt. The 5.5 amp could be the AC rating, which would be more like 660 watts which does sound a bit high.

EDIT: I looked on Dometic website and the smallest unit I saw in the "RV, Boat, and Truck" class was rated at 175 watts AC. I didn't see anything rated by amps. But that is a smaller load than our fridge and what I was contemplating for sure. Largest was 325 watt rating which is comparable to our fridge and my experience. I still say use propane while off grid though. Any load of 18-sh amps from your batteries throughout the day is going to be hard to put back in without more solar. A caveat to using propane - it still does draw a continuous load of around 1 amp DC while the unit is powered on to power the control panel and gas solenoids.

Yes, a generator is a good idea if you are full timing. But we never packed our generator along for several years because its only purpose was to run the air conditioner. Up until I installed a Micro Air hard start kit, it was unreliable for running the air con so I didn't bother bringing it. We are long weekend warrior campers and solar has always been sufficient for our power needs. We run out of water before we run out of power. The inverter types are the industry standard for RV, they are quiet and the 2000 watt models can be managed by one person. The Honda is a bit easier to manage, our Yamaha is quite a heft for one person but I manage. The comment about a better charger is a good one, but I suggest going to bestconverter.com and upgrading your RV's converter rather than getting a stand alone charger. The RV's converter IS the 12V battery charger. You want one with a reliable "boost/bulk" charge mode. The WFCO models that are the usual OEM converters claim to have a bulk mode but are notorious for not actually ever charging at 14.4V.