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I say don't overthink it. Go ahead and buy three off the shelf 12v lifepo4 batteries and run them in series. (Just make sure the bms they use allows for more current then your worst inrush currents) Then buy three cheap voltmeters, hook one up to each battery and mount them on the dash...

Lets start with the wire and breaker sizing for your solar panels. Can you specify the open and max power current and voltage on your panels? Your 60A charge controller can easily deliver 768watts of power to your 12V system and with 600watts worth of panels you'll be just fine there. But...

So with four batteries in series you were setting this up to be a 48v system? It seems likely that the damage occurred the last time you charged it.

You basically have three 300Ah 12V batteries in parallel and you want to be able to disconnect one or two of them and leave only one or two 12V 300Ah battery running. Disconnecting should be fairly simple if you have a large enough breaker. I would be way more concerned about the process...

The input voltage of most modern (low power) appliances is actually quite variable. If I'm trying to see if something like a router will work on a different voltage I can go up but I never go down. If it takes a 9v wall wort I suspect I can power it with a 12v supply, etc. Keep in mind even a...

Check your settings in your manual. Your CC is fancier than the older tracers and you can tell it to drive that port under different conditions.

The resistor-wire heater and insulation are now rigged up. Time to commence thermal testing

Yes, your SCC's can be in parallel all attached to the same battery. I'm currently doing a very similar project, with three strings of 2 320W panels. Each of my strings land on a 30A Epever charge controller and all three charge controllers are attached to the same 200AH 24V battery.

If you have a 12v 100ah system then you have at best 1200 watt hours of energy. (If your battery is lead, cut that usable amount in half). Assuming LiFePO4 batteries, your 1200 watt hours of energy would be dropped to zero in .85 hours with a 1400 watt load on it. (1200/1400 = 0.857 hours)...

Seems like all you need is a simple 1:2 transformer

Your title says this is a lifepo4 but in post 8 you say it's Li-ion. Which is it? It makes a difference

Quick question - Why two 100ah 24v batteries when they also offer a 200ah 24v battery?

How exactly did you arrive at this figure? It seems suspiciously/unreasonably low. You're proposal is a 2p2s battery bank that's a nominal 25.6V and 200 AH deep which as you noted would yield roughly 5120Wh. In my area I use 4 equivalent hours of full production, you have noted 5 which...

I assume your power needs are significantly smaller when you aren't there. Do you still run the webcam? If not, then is your real goal to make a heated storage chamber for your batteries so that the cold storage doesn't damage them?

Interesting, thanks for the detailed writeup ? You seem to have chosen a ~70w heater for your battery to heat it up quickly and cycle on and off. I went a slightly different route with a similar 100ah lifepo4 battery. But instead of a "hot" heater I made a very small heater, roughly 6 watts...

For all those wondering how to handle a worthless loser like this "Sunny Rio" fellow, just hover over his username and click ignore.

No, I'm not an urbanite and his urban gardening stuff was sold to people who didn't know better. But some city folk loved the guy before he came clean with them

And if you choose to take up more space than the original batteries (use more height, etc) just make absolutely sure the new batteries weigh the same or less as the old lead acid ones since the car was clearly only designed to carry so much.

He made his living selling books telling inner city people that they could run CSA programs growing on abandoned lots in the ghettos. No doubt he's about to come out with a book fleecing the most vulnerable in the prepper community too.

So if I was to spitball for my location I'd say that your 540 watt's worth of panels would deliver about 2200 watt hours in a day. (Which at 12v would be roughly 180 amp hours) You have 960 watt hours of "continuous load" and you have 665 watt hours of your 7 hour distributed load. So...

Yes, that is an accurate statement. And coincidentally, that's why I have a battery heater and also a low temp cutoff for the charge controllers should that ever not keep up. And it's in an insulated compartment in a shed.

No, I'm not talking about keeping the solar connected to the charge controller, I'm suggesting the batteries just "sit" all winter in a box that's heated with a solar panel driving a heater through a thermostat

I'm interested in playing around with an IQ7 microinverter and I'm not sure how one connects to it. Specifically, what hardware was involved that allowed you to update the firmware on yours? Do I need that $700 box or is there some other method? And if I do pay $700 for a gateway can I use it...

Rectifying power supplies can be very efficient but generally only in a tight design range. Rectifying power supplies that are meant for a wide range of loads are always a compromise of a design which bleeds energy at most power levels. For this reason, things like the wall worts we all use to...

Your charge controller can accept 150v input and it can "deliver" about 770w of power to a 12V system. But there are a lot of inefficient ways to wire it in. We need to know the parameters on the sticker on the back of your 8 100w panels. Specifically the open circuit voltage and the short...

Yank the output wires off of your 24->12 step down converter and run those directly to your new lights. If they power up like they did with your bench meter then they probably draw more power than your converter can supply (while it's also supplying all of your other 12V needs). If that...

Can you quantify this load? How many amps does it pull on a hot day? How many hours a day do you want to run it? Understand the load and all else falls into place.

There's a lot in this thread and diagram but I'd like to focus on this one part: The current coming out of a charge controller is higher than the current that goes into a charge controller, that's their whole thing. Big voltage small current becomes small voltage and bigger current. So I...

This is a 15a plug. I believe you need the larger 20a style in case you plug something big into it. You can tell which is which by the extra notch in the full power one. 3000w/110v= 27.27a

An incandescent light bulb is just a resistor, only it gives off both light and heat, not just heat. You can put any voltage to them and they'll take it, however if you put too high a voltage they will overheat. (You have the opposite problem) Headlight bulbs may not be simple resistors...

You make a number of good points, it's time to rethink this operation. The benefits of adding some smarts to this system outweigh the downsides of the added complexity. I'll still use concrete as the heaters but I need to rethink their operation and composition. Fixed power modulated over...

Again, where did this number come from? If it's accurate and assuming you pay the average rate in NJ which I'm told is is 17.35 cents per kilowatt hour, your current on-grid electricity bill is roughly 72.4 pennies a day. If you currently pay more than about $21 per month in electricity...

I think it's worth noting that you need to respect minimum on and minimum off timers for compressors/ac. I use water (barrel) heaters as a dump load in a greenhouse during winter and circulator and exhaust fans during summer. I am careful to lock the dump load on or off for a minimum of 5...

It feels like we've diverted a bit from the cooling topic of this thread. :-P The low temp cutoff for the charge controllers is set at 35° inside the battery's insulated compartment. The 1.9kw array on that project delivers 75A [nominal, max] and on a 200ah battery that's .37c.

Charging is the problem. Picture that they're all down 2 volts from a full charge. You have 2 in parallel and one in series with those two. The single one in series will "fill up" twice as fast as the double one behind it. The charge controller will still see the voltage as being low and...

I don't see any photos of the inside. Is it a 12v regulator with panels feeding it?

Perhaps go old school? Any chance you can dig a hole below the frost line? ?

I have to admit that I'm not understanding where the rocker switch is seeing only the back view. But if the issue is that the rocker switch is a thruhole part then there would be no easy wire to snip. Instead it would be a solder job where I'd solder a wire into each of the rocker through hole...

It doesn't look any hotter than the wire

A 100AH 12v lithium battery is ample to run a freezer as a fridge for 24 hours as long as you don't leave the AC on when it's not needed. But your power needs to run it as an actual freezer are much greater. You'd certainly be on the hairy edge at best. An energy audit of your freezer...

I use BACnet controllers and not plc's but the concept is the same, the controllers I use just allow higher level programming than a plc. But the issue of who maintains them if I get hit by a bus is a consideration I've chosen to deal with head on. My solution is/was to have several extra...

And how is their performance being quantified. I'm at a very small scale so pem is about $15 and mppt is about $90. I ran 4 years with pwm and 2 with mppt. But because I'm not running two systems side by side in the same conditions I do find it hard to quantify the difference in harvesting...

What is your temperature goal here? How hot would you allow them to get before cooling? When cooling them how cold do you consider cold enough?

Is this setup meant to deliver 110vac around the clock? If so, home the battery bank and inverter on/near the panels on the main house. Then you're basically running any old extension cord from there to your tiny house with minimal losses. And no expensive wire.

You not using that output is why you have been able to drain your batteries so low, your CC has the ability to fix this but it's ut to you to use the functionality. Actually I just looked up your manual (I'm assuming it's a Tracer4215BN or very similar) and it appears that unlike the other...

This saddens me greatly. We've been growing food for 412 Food Rescue for years now. Here's hoping they land on their feet before the spring crops start coming in.

Have you considered designing it so that it's idiot proofed? If you route the inverter "go" signal through a relay driven by the courtesy power on your charge controller you can be assured they won't overly drain the battery. Go one step further and put a mechanical timer on the coil side of...

I have the exact same scenario as you, a power panel in a shed with 6 inverters, three charge controllers and some other equipment. The panel itself has a fan to exhaust heat into the shed. But I use one of these to exhaust heat out of the shed. https://www.amazon.com/gp/product/B07Z1VNGS8...

This is the real solution. Wire this up and allow it to bleed off the high one for you. I'll go a bit deeper below but this is the actual path you should take. Otherwise you can put any resistor across battery 8 to burn off the excess .025 volts. Say for example that I had a 1/4w 100ohm...

Use the 12v side but not the power side. I'm unfamiliar with your inverter but the first thing I do to mine when I buy them is I pull the on/off switch out so I can turn it on and off without having to disconnect the power to it. Run your timer/logic in 12v and have it connect or disconnect...

Rs485 requires twisted pair wires for distances over 500 feet or so. The higher the baudrate, the shorter a distance you'd find useable but several thousand feet is possible at slower rates. If there is a shield on your wire connect it to the grounded case at one end and leave it open at the...

What exactly are you powering? Most computers like to be fed DC anyway, why not tailor your system to feed them DC directly? Then the only "backup" part is how you charge the battery bank. Solar when possible, grid fed below a certain voltage, etc.

Welcome to the club then, half of my idiot proofing is to keep myself from doing something stupid, not others. ;) Most charge controllers offer a dry contact for courtesy power. This turns off at a preset low voltage and turns back on at a preset slightly higher voltage. Run the battery...

Indeed. But do you really want to be one of the first folks to put a butane-based refrigerator in a kitchen near a stove? I'd be happy with it for an outdoor fridge but I'm not all warm and fuzzy thinking about using one in a kitchen.

Have you verified that the panels have bypass diodes installed? If you pop open the back panel on them you should several diodes that are strung between the two wires that exit the box. If your panels are missing them then any shading on any panel will be the same as that shading on all three...

That's the sort of behavior I'd expect from a bad battery. If you unplug the fridge the inverter can probably power on for a while without tripping out like it does under load, right?

Traditional chlorofluorocarbons or hydrofluorocarbons. Of course the first kills the ozone and the second is about the worst greenhouse gas ever conceived of. I'm not saying there's an easy decision. I'm just not sure I want to be a guinea pig putting compressed butane near an open flame.

Let's back up a bit. How is the current system set up and what is it doing that needs to be improved?

Yeah, that smoker is using a very large amount of energy. That 1400 watt device uses the same amount of power as 14 old school 100w bulbs at once. Or if you're using modern "100w equivalent" bulbs you could run 107 of those bulbs at the same time just to use as much power as that smoker...

Epever says you need to address them differently and wire them together when they are used in parallel, presumably so that they don't have spikes like this. It appears as though you haven't got them sharing data so I would expect the issues you are seeing. If you turn one epever off does...

That's a fairly tactful response. I'd suggest it's a little weak on the anti-woke side of the explanation though. Perhaps changing the word insincere to misguided would be a closer fit?

You can get away with two coathangers at 6ft. Just get the polarity the same on both ends

At that price I suspect there is no advantage to going that route. Here in the US we can get an Enphase microinverter for less than half that price. Probably a lot less in bulk...

If you're using a row system, why the cloth? Have you considered a cultivating tractor? Depending on size you might find a two wheeled cultivator to be a big improvement over the stone approach. As for coming clean, he got drunk and posted some videos disparaging people stupid enough to have...

Have you considered wiring a second set of outlets in the building? Keep the existing generator-based system as is but add a proper panel feeding a few new outlets that are run only by solar. This way if/when you take components home the rest of the house still works as it always did. If...

15V is just as troubling as the cutoff voltage of 10V, perhaps more so. What's allowing it to charge to this level? But as for guessing- I'd say that you have a BMS that's cutting your battery off and back on to protect itself. I'd remove parts until the problem went away and then see what...

The larger the inverter the larger the amount of energy it wastes around the clock even when there is no load on it. For that reason I always select the smallest needed for the job, especially on a small system. But that brings up the larger issue here- you need way more panels than the 600w...

Forgive me if this is a silly question, but what is a voltage rating in the context of a busbar? I completely get that they need current ratings to ensure that they aren't undersized causing them to overheat. But what does a "voltage rating" mean on a piece of metal that has a zero (or at...

Wow, I always heard it called the "nanny state" but I thought that was because they banned guns and then knives. Here in the US of A we can distill all the liquor we want. We just have to drink it ourselves or give it away free to our friends. It's the possible tax-avoidance that drives the...

One last thought, you didn't accidentally cross any of the wires in this diagram, did you? There's no path from black to either green or blue right? And no path from red to either green or blue? If you had shorted something in attaching this stuff it would not have worked at all. But...

What's the VOC on these panels? I'm on mobile and can't seem to find it anywhere in the listing.

Where are you located? Are these to be indoors or out? What is your precise goal? Someone in Texas probably only needs to cool their fridge and freezer year round. Someone in the North woods might also need to heat them at times during the winter months...

The load I'm suggesting you run on the port is the current draw to run the inkbird. It can be fused at least than one amp because it's only enough power to run the pic processor, drive a tiny relay and power the 7-segment displays. The inverter is simply told to turn itself on and off by the...

Careful- you meant to say series. In parallel it would pull a massive amount of power due to the super low resistance. Could get dangerous. ?

There are several lithium chemistries and they have different needs. Do you have lithium ion (Li-Ion) or lithium iron phosphate (LiFePO4)?

So you have 8 panels all in parallel? Do you have blocking diodes on each? What gauge are the wires to each panel and how long are they? What gauge wire comes out of the combiner box and how long is it?

A quality set of automotive jumper cables

It's specifying 8 AWG for roughly 8 amps running 10 feet. That's an oversized miscalculation. How can someone trust a widget that is so expensively mal-designed?

I'm excited that this battery credit is based on size and not usage. The way I read it I can still design a completely non-grid tied secondary system at home and get $ back for the batteries. If they forced it to be part of a grid tied system it would be a much harder sell for me.