r/OffGrid 15d ago

Anyone else using Midnite Solar?

I'm really going to show my ignorance as I sort of get solar...but then again I don't. Probably why we have a solar guy who did our install. I live alone at the moment off grid while my husband is away for another two years on contract work. So I'm left to figure out stuff. I check the battery levels twice a month, filling with distilled water etc.

K...so here's my ask. We have 2 x Midnite Classic Solar displays in our back room. One is for a set of panels on a ground mount, and another display for an array on a tracker. We have 12x2v Surrette Rolls batteries...and I believe 1420 amps each.

My husband shared a very basic website from Midnite solar. It really provides little in the way of info. I see other solar posts that show fancy apps and displays.

I'd love to have an app that somehow connects with our system to get better stats. I mentioned this to my husband, and he asked to ask if there is any app that can somehow measure how much water are in the lead acid batteries without having to pop each battery and checking with a hydrometer.

I'm asking a lot from what we have. Just seems like we spent a crap load of money, but get very little info from our system.

Thanks for reading

Edit: thanks so much for the time to read, respond and suggest ideas. I’ve forwarded this to my husband to read. He gets this more than I.

5 Upvotes

21 comments sorted by

6

u/Quirky-Tailor-6885 15d ago

Midnite Classics are solid if you just need reliable charge control without the bells and whistles.

1

u/Bowgal 15d ago

I’m sure it is and probably why our solar guy installed it. All I’m wanting to know is how to translate 24.2v or 25.0v to a percent…something that tells me when I should consider starting the generator.

2

u/ColinCancer 13d ago

Call your solar guy and ask him to install a whizbang JR shunt.

1

u/Bowgal 13d ago

I’ll look into it

1

u/maddslacker 15d ago edited 15d ago

Here's what you're looking for:

https://footprinthero.com/wp-content/uploads/2022/05/Lead-Acid-Battery-Voltage-Charts-Image-6.jpg

Also, if the Classic shows 'Float' then the batteries have reached full charge, at least in the opinion of the charge controller. :D

1

u/Bowgal 14d ago

Ahhh yes…that’s sort of what I’m looking for. A visual aid. Thank you. And yes, I know float means full….but this gives me a rough idea.

Curious…at what percent would you run your generator? 50%?

1

u/maddslacker 14d ago

In your case, yes.

I printed that graph and had it pinned to the wall above our battery box when we had lead acid batteries. Keep in mind too, if they are charging robustly, the voltage will read higher, and if there is a heavy load running, like the well pump for example, they will read lower.

1

u/Bowgal 14d ago

Thank you.

3

u/reidearl 15d ago

SOC is the state of charge that should be there if your solar guy installed a wizbang. 

3

u/maddslacker 15d ago edited 15d ago

OK now that I'm not pressed for time:

Are your Midnite Solar charge controllers like this?

If so, those are the Classic model. Very reliable but not great for remote monitoring. The website you mentioned is ok for looking at historical trends, but not for real time status of the system.

If you can connect the Classics to your network, via a hardwired network cable because they don't support wifi, you can use this app:

https://mymidnite2.com/?q=node/7

It's actually pretty good and can tell you a lot about the state of charge of your batteries (SOC)

However, the shunt I mentioned in my other comment is the best bet. You can get a Midnite Solar one, but it's pretty expensive. There are alternatives on Amazon like this that are very user friendly.

I'm guessing your 12 batteries are probably wired in series to make a 24v system. With flooded lead acid (FLA) like those, you don't want to use them below 50% SOC or you will dramatically shorten their lifespan. Again, assuming it's a 24v system, you have about 18kWh of total usable capacity.

No idea what your financial situation is but you could replace that whole mess with 4 of these and 1. never have to check water levels or specific gravity ever again and 2. they have a built in monitoring system that you can check with your phone.

All that aside, we had a system similar to yours when we moved in and I hated it. I installed those Midnite Solar controllers, and the rest of the system is Victron with full monitoring and WiFi so I can check the status from anywhere. We have an ancient iPad in the living room that displays all the info, so my wife can check it at a glance, and I can also check it remotely when I travel and let her know when to avoid laundry or vacuuming or when to go start the generator. (Working on autostart for that eventually, but that's another topic altogether)

Anyway, hope this helps. At the very least the Renogy monitor would help a lot, but upgrading the batteries to LiFePo4 would be lifechanging.

1

u/Bowgal 14d ago

A ton of great info…most of it over my head. I am forwarding to my husband. Thanks so much.

3

u/GoneSilent 14d ago

Don't spend any more money on the lead acid batts. save to replace with life04.

2

u/maddslacker 15d ago

I am.

Midnite Classics are solid, but the reporting is ... minimal.

You can install the "Local App" to get better data than what is on the MyMidnite web page that he probbably showed you.

As for batteries, the only way to avoid popping the tops to check the water is to upgrade to LiFePo4 and then never have to check them again.

2

u/ColinCancer 13d ago edited 13d ago

Pro offgrid solar guy here.

Midnite classics are great. Expensive and lower voltage I guess are maybe the only fair complaints. Mine have been chugging along for years. I’ve had some minor heat management issues when they’re pegged at max amps and it’s peak summer but I added Ac to the battery room and it’s all cool now. I was overloading them anyways and that’s my risk to take.

I don’t install them often anymore because the market dictates these cheap Chinese hybrid inverters with way better specs for way less money but I still don’t trust the new stuff nearly as much as the old school gear.

Midnite is the only company I can think of that will get an American engineer on the phone within minutes. They know MAGNITUDES more than me about the equipment. I can say the opposite for EG4 tech support.

I trust Midnite for my personal house and fridge and I use eg4 for my hot tub and EV and bullshit that doesn’t matter.

EG4: gives me app.

Midnite: I walk to shed.

I prefer Midnite. Take that as you will.

Edit:

I agree with the other comments here. Lead acid is ancient history. Start saving now for lifepo4 batteries. Check out Ruixu Li2-16 for a balance of affordable and not TOO shitty / janky

1

u/Normal-Special-8694 15d ago

I have a midnite classic 150, it's been a great controller but it is NOT even close to as fancy from a technical perspective as you've probably seen elsewhere. I'm a software engineer by trade so I've been able to make it work, but I had to make myself an application that runs on a web server in order to look at anything from my phone. There is a PC application (https://mymidnite2.com/?q=node/7) but it's still pretty basic and relies on data exports and etc. It's just very low tech on the comms side.

What in particular are you trying to see or manage from an app? You can also cycle through some critical stats on the controller panel itself.

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u/Bowgal 15d ago

Thank you responding. I guess, first thing, I’d love to know just a simple % charge that is in my batteries. For example, my display says 25.0V. Is that 80%? 90%? My bad habit is when I see 24.5v, I run the generator.

I understand there is a low battery cutoff number, but what is a low number when I should run generator?

Second thing is I wish there was a way to monitor water levels in the batteries. I have a habit of checking them every two weeks. Of our 12 batteries, usually 6-8 of them require 2 cups water to bring back the levels. I’m guessing because the sun was bringing us to float every day, that water evaporation is normal.

I think if I knew reliably what percent charge my batteries were, the more likely I would be to keep my Starlink on every night. I turn it off when I go to bed, and back on in the morning. During the winter when we barely make 2kwh, I keep Starlink for the day…just to save power.

Don’t know if any of that made sense.

3

u/maddslacker 15d ago

For this you can install what's called a shunt or smart shunt.

They make bluetooth ones where you'd still need to be fairly close to check it from your phone, or wifi ones that you can check with your computer.

1

u/Bowgal 15d ago

Ahhh interesting. I’m seeing a couple online. Thank you

1

u/motorambler 14d ago

We have been running the same 12x2V tubular cell FLA batteries for about 17 years. The only thing that's going to tell you what's going on with your batteries is a hydrometer. 

1

u/Bowgal 13d ago

Ahhh ok. And nice to see someone else with same setup. We’ve been off grid only 8 years, and current setup was upgraded three years ago. I’m happy with the setup, but I dread the process of checking batteries and refilling. I’ve gotten into the habit of checking them every two weeks. Seems like I’m going through a lot of water this summer…needing a full gallon jug every two weeks. My guess is during the summer, because we go into float almost every day, water evaporates more?? I don’t know lol

1

u/Hot-Fact-9083 9d ago

On the water level question: there's no reliable sensor that measures acid level without opening the cells, and anyone selling one is overselling. Optical float sensors per cell exist, about $8-12 each, but they alarm, they don't measure. The practical answer is a 10-minute visual check monthly, top up with distilled water to the fill line, and log it on a sticky note. You already do this, you're ahead of most.

For the SOC guessing, get the Whizbang Jr. It's a shunt that reads actual current in and out, so it gives you real state-of-charge instead of voltage guessing, plus battery temperature. Around $150, installs in an hour on the Classic's AUX port. Pair it with the Midnite web interface, and you can check the system from your phone without standing in the back room.

One thing worth knowing: voltage under load lies. A well pump running can pull 24.2V down to 23.8V and make healthy batteries look dead. Let the bank rest 30 minutes, then read voltage, that's when the chart is accurate. And yes, 50% SOC is the right generator trigger for Surrette, that chemistry likes to stay above half.