What is Reddit's opinion of Kohree DC/DC Converter Regulator 24V Step Down to 12V 20A 240W Golf Cart Low Voltage Reducer Buck Transformer Waterproof?

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You can do it two ways - if the 12V loads are very small compared to the rest of the system, you can connect a load (with a fuse, naturally), to the negative terminal of your battery bank, and a positive terminal halfway between the series banks to deliver 12V. The upside is that it is very simple. The downside is that if you have a lot of 12V loads you can unbalance the battery bank and accelerate wear.

The better way for larger loads would be to use a "24V to 12V stepdown converter". These are sometimes called "transformers" but that isn't correct - they aren't actually transformers. But they do step down to the voltage you want. You'd get one of the correct size for your loads, and connect it in parallel with your inverter to the battery bank negative and positive terminals. Here is an example of a 240W unit on Amazon (no specific endorsement, just an example from a search): https://www.amazon.com/Nextrox-Converter-Regulator-Step-Down/dp/B00BWKXTUU

It would also be possible to use a 120V -> 12V power supply connected to your inverter's AC output, but I wouldn't usually recommend that, since it is a lot less efficient (you have the DC:AC losses, then the AC:DC losses again). The only reason you might want to do that is if you have a complex control system, and are relying on the inverter to do coulomb counting and low voltage cutoff and whatnot. If you have a simpler system, no reason not to go right off the bank with a DC:DC converter.

You will discharge the battery you are drawing the 12V from causing it to wear out sooner. Here is an example of a DC-DC converter that should work fine in your application.

thanks, following your other link I also came across this

DC/DC Converter Regulator

I guess there no inexpensive controller that can measure mah then.

which one you think would work better the one from amazon or the ones from ebay.

Thanks.

If it is a charger made to plug into an auto cigarette lighter, It is rated for the lead acid voltages. Even during charging of the lead acid battery.

A better solution to have a balance draw from the 24V, is to use a step down converter. You can google for others.

You could probably use something like https://www.amazon.com/Nextrox-Converter-Regulator-Transformer-Waterproof/dp/B00BWKXTUU, a high power switching regulator. But that's also a bit of extra weight. Plus any kind of regulator/transformer will dissipate heat relative to the current you pull through it, so they're better for low-current applications. I think you'd need a really unusual reason to want this setup instead of just using a new 3 or 4s battery.

What's the wifi supply voltage? You could use this guy. https://www.amazon.com/dp/B00BWKXTUU/ref=cm_sw_r_cp_apa_glt_fabc_EW74MMSAZK6D63MHJ69S

4/0 is really big though. Like, omfg. XD Have you ever seen a 4/0 AWG wire?

What DC loads do you have? (Water pump, lights, etc.?) I need to know how much load you'll have at once, max, to recommend a converter.

I used this one for my camper trailer and it worked great; didn't even complain with my water pump and all the lights on.

https://www.amazon.com/gp/product/B00BWKXTUU/

This one does an even 12 volts though, but it worked like a champ for over a year so far. They do make a basically identical one set to 13.8 volts, I can't find the amazon link at the moment though.

EDIT: Read reviews from where you buy these, there are some crappy variants, but reviews will tell you the difference. Also, good thing, the bad ones die quick, so it's likely you get a failure on install, or it'll last for a long time.

EDIT 2: Found this one: https://www.amazon.com/uxcell-Converter-Regulator-Transformer-Waterproof/dp/B01LY8D7U0/

I've bought a few converters (not this one but other similar items) from this 'uxcell' company. Had good luck so far. :)

Doubtful, the starter would probably blow that one out.

This is the one I used. https://www.amazon.com/dp/B00BWKXTUU/ref=cm_sw_r_cp_apa_i_LdwvFbPYPGGND

Hm perhaps, but when you shade the panel it immediately stops charging.

Anyway, I figured out what I need to do. I'll get this DC-DC converter:

Nextrox DC/DC Converter Regulator 24V Step Down To 12V 20A 240W Low Voltage Transformer Waterproof

To convert the 18V from the 50W panel to steady 12V. It's 96% efficient which is great.

And one of these:

PD Type C USB Car Charger Socket and QC 3.0 Quick Charger 12V/24V

Which will give me a USB-A with QC 3 and a USB-C with PD that I can use to fast charge my phone and an Anker power bank (which will effectively be my battery), and I'm set.

Very excited to get it all working. This may be the cheapest way to get into solar.

That's not that difficult, you can order similar modules on Amazon for abour $40.

Something like this

Has anyone ever tried using a 24v power supply and step down the supply to the ramps board with a converter?