I'm already apologising...

[SunEagle]

That's the problem with solar/battery systems. They work fine until they don't. Usually because the battery has been over discharged and weakened or there isn't enough panel wattage to get the charging amps up to what keeps the batteries happy.

Summer charging is a different animal to Winter charging.

[organic farmer]

Hey, apologies for the noob questions incoming

System is 24v 2x360w panels, 2x12v 270ah agm batteries with a 30a proflex charge controller and 1700w trojan inverter.
> >
> > I went from in summer the batteries being 100% charged by 10am, running deep freeze 24/7, washing machine a couple of times a day and the water pump when required, and barely made a dent in the SOC...

Question 1, is it normal for the batteries to lose charge over a few hours even without any load and the inverter switched off?

We've come into autumn and the charge controller has started giving me really odd numbers, like -/+ 40% SOC within an hour etc... Can no longer run the deep freeze alone for more than a couple of hours without the batteries running to low from 100%

When was the last time that you did an equalize charge?

It sounds to me like your batteries are dying. If any one cell dies it will pull all of the other cells down with it. The only way to avoid that is to be doing regular equalize charges.

I have three chest freezers. they are all on timed power strips, so they can only run during daylight hours and never from the batteries.

[chrisski]

I’m surprised you got so much out of that. What you described would have wiped my 12 volt 458 ah batteries and 1350 watts of panels out, especially overnight. The only thing I can think that would hav kept your system running so much is if it was built this winter and these lower numbers are because the weather is just starting to get warm and the freezer is just now starting to work.

With healthy batteries, unloaded batteries and disappearing charge is not normal. My only guess is with the inverter turned off there’s a load on the system, perhaps on a DC leg. You can measure the load with a good DC clamp on meter.

Perhaps the SCC is not charging anymore because its shot or bad connections from the panels. Measuring output to the batteries during charging with a lamp on meter would help.

[velo27]

Hey, apologies for the noob questions incoming

System is 24v 2x360w panels, 2x12v 270ah agm batteries with a 30a proflex charge controller and 1700w trojan inverter.
> >
> > I went from in summer the batteries being 100% charged by 10am, running deep freeze 24/7, washing machine a couple of times a day and the water pump when required, and barely made a dent in the SOC...

Question 1, is it normal for the batteries to lose charge over a few hours even without any load and the inverter switched off?

We've come into autumn and the charge controller has started giving me really odd numbers, like -/+ 40% SOC within an hour etc... Can no longer run the deep freeze alone for more than a couple of hours without the batteries running to low from 100%