Battery needs to be jumped if drained

[sunshine_eggo]

Yes I'm getting my battery readings from the charge controllers. Good to know! I thought I could rely on "renogy's" charge controllers for that.

Renogy's charge controllers have no idea how much is going out of the batteries. It only has voltage to go on, and voltage is only reliable in very specific cases.

I'll invest in some actual battery monitors.

Good. Will lists a few on his website. Stick with the top two options.

I don't think I'm using more than what my solar panels are providing.

You're very likely wrong unless you're using heavy loads at sundown. 11.7-12.3V @ sundown is a VERY low state of charge.

At peak sun hours I get anywhere between 750-900W from them and the batteries are usually at "100%" even when my AC is on.

Again, 100% is based purely on voltage, and for lead-acid. it's very easy to get a LFP battery voltage high enough to report "100%" but getting them to 100%.

My AC pulls about 90W.

What A/C unit pulls 90W? Did you mean 900W? Very small 5000BTU window units pull 400W+

I live in the High Desert of CA, the sky is almost always clear with scorching sun.
Happened again! Around sunset yesterday I had about 13V at "90%" and woke up to dead batteries :/

You're not collecting enough sun for your loads. 13V under light load is still likely a low state of charge.

What are the highest typical voltages you see at the battery?

 

[conquistador]

A "12V" LiFePo4 at 13V is almost empty. A full one has 14.2V.
Just get yourself one of these for around 30$ so you can measure current at any time in the most easy way.
Then you just measure what you draw during the night and you calculate how much battery capacity you need.
If you run the aircon during the day, then all your panels provide goes into the aircon.
Just measure how much goes into the batteries during your sunset charging hours and then you have numbers to talk about.
PS, make sure that you get a clamp Amperemeter for DC , the cheap AC ones will not work.

 

[Wael]

Renogy's charge controllers have no idea how much is going out of the batteries. It only has voltage to go on, and voltage is only reliable in very specific cases.

Good. Will lists a few on his website. Stick with the top two options.

You're very likely wrong unless you're using heavy loads at sundown. 11.7-12.3V @ sundown is a VERY low state of charge.

Again, 100% is based purely on voltage, and for lead-acid. it's very easy to get a LFP battery voltage high enough to report "100%" but getting them to 100%.

What A/C unit pulls 90W? Did you mean 900W? Very small 5000BTU window units pull 400W+

You're not collecting enough sun for your loads. 13V under light load is still likely a low state of charge.

What are the highest typical voltages you see at the battery?

My bad yes I think it's 900W. I have the Amp meter/Voltage monitor recommended by Will (the "bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage with 100A current chunt"). When I have the AC on it says on it 90W on average, I'm assuming it's missing a zero or I wired it wrong but yeah I do get "90W Power" on the display. I thought something was odd. But I just googled how much the 12k BTU Mini Split from Mr.Cool I have draws and it says anywhere from 288W to 1480W depending on the settings. So I'm assuming that 90W I'm seeing is actually 900W.
The highest voltage I get from my batteries is 14.4V. For the most part when I have the AC on during the day they drop to ~13.5V.

 

[sunshine_eggo]

Guessing but 90W may be the NET consumption/charging.

The Bayite is pretty limited. It only allows power consumption checking in 1 direction. You have to manually reset the consumption value. Recommend you reset it and see what your consumption is for 24 hours.

Just estimating with round numbers, you have enough battery to run the solar for about 4 hours. You have enough solar to run the A/C for about 4-6 hours. You don't have much more for anything else.

I'm now 100% certain you're exceeding your solar.

Solar determines how much power you can use in a day.

Battery determines how long you can run loads without charging.

If you exceed your solar harvest, you will keep dipping into your battery every day until it's depleted. That's where you are.

 

[Wael]

Guessing but 90W may be the NET consumption/charging.

The Bayite is pretty limited. It only allows power consumption checking in 1 direction. You have to manually reset the consumption value. Recommend you reset it and see what your consumption is for 24 hours.

Just estimating with round numbers, you have enough battery to run the solar for about 4 hours. You have enough solar to run the A/C for about 4-6 hours. You don't have much more for anything else.

I'm now 100% certain you're exceeding your solar.

Solar determines how much power you can use in a day.

Battery determines how long you can run loads without charging.

If you exceed your solar harvest, you will keep dipping into your battery every day until it's depleted. That's where you are.

I see. Yeah sounds about right. Thank you so much for all your input!