Post Installation Brain Cramps

[Haykin]

I just finished installing a small solar resource in my shed to help reduce power consumption for my storage freezer.

I’d like to get feedback on how I should configure the system to handle the load properly with the parts I have installed or what I could do to improve it with as little $$ as possible.

I followed Will Prowse video on setting up a 12v system and I have an MPP solar 12v 1kW all-in-one unit managing power, a single 12v LifePO4 100Ah battery and two 100W monocrystalline solar panels in parallel.

Everything appears to be running well and I even plugged the freezer into it and after an initial auto-switch to utility to provide enough juice for the freezer to start up it switched back to battery and ran for the rest of the day on battery with solar providing recharge current.

I should note that I referenced Will Prowse MPPsolar configuration settings tips to set mine up. Although some settings were not available to me. Assuming this was because I’m in a 12v single battery configuration.

One thing I did not take into consideration was after sundown. At some point around 10pm the unit started to alarm [even though the audio was disabled] and there was no fault code on screen, it was just beeping over and over again. Even after I turned off the power switch. It wasn’t until I unplugged it from utility that it shut down and screen went black.

Is it safe to say that the alarm was due to battery being discharged and no source of recharge power?

This morning I changed option 16 in the config to include utility and solar as the simultaneous source for recharging the battery.

I’m just not sure why the utility power triggered the alarm and why it didn’t provide power to the freezer.

I'm considering changing the setup to act more as a UPS for the freezer but not sure how best to do that. Any advice would be appreciated!

 

[Mattb4]

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I’m just not sure why the utility power triggered the alarm and why it didn’t provide power to the freezer.

...

The AIO is powered by the battery. If the battery voltage drops below certain set points various actions take place. The first being the Battery under voltage alarm (the continuous beeping you experienced which does not go away until battery voltage goes back above it ). Below that is a few other set points such as Battery over discharge delay time and the shutdown voltage set point. The last two turns off the AIO and you get no output either in AC bypass or from the inverter.

Concerning your setup. Your 2 - 100w panels are insufficient to supply power to cover the idle current the AIO will draw over a 24 hour period and cover any loading. To run your freezer and stand any chance of recharging yoru battery I would expect you need at least 600w. Also just one 12v 100ah battery does not give you much leeway to power teh AIO and operate a load through the night. Your AIO will likely switch to AC bypass sometime before morning.

 

[Haykin]

That makes sense. Thank you.
So it may be best to get an actual UPS or generator for the freezer for now and use the current solar setup to power my workbench during the day for things like battery recharging for my cordless tools and running my AC tools, like a drill etc. At least until I can get more panels and batteries to meet the needs of the freezer.

Does that sound about right?