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To the OP, @JohnPickett: This forum is the best place on the internet to find people who can help you solve a problem that you're having with your DIY power setup. Just look at all the posts above with people genuinely trying to help! There's a ton of know-how and experience here, and also a...

It's the difference between brakes on your car (a disconnect) and wheel chocks (an isolator). If your car is stopped, they do the same thing. If it's moving, one is useful and one is dangerous.

Just throwing out a shot in the dark here…. But do you have a N-G bond on the inverter circuit? I’d start by measuring ac voltage from neutral to ground, hot to ground and hot to neutral on a circuit that’s off.

The short answer: Your BMS is not burning that power. It would get pretty how if it was burning 70W constantly. That 1.39 A is either the idle draw of everything else in your system (likely), or a calibration error (less likely).

I don't see any pushback on installing a fuse. @JWLV said they wouldn't bother with a fuse, and I said a single panel didn't need to be fused, and I gave reasons why. Two panels in parallel don't need to be fused either, and for the same reasons. People come here for information, and the...

The JK BMS's work for a range of cell counts. Any of them that will do 16s will also work fine with 15s. But your idea of adding an additional cell to get to 16s sounds like a better plan for future compatibility. And as long as the new cell has at least the same capacity of the old ones, it...

Interrupting AC and DC are very different. I don’t think I’d trust those ac-rated fuses for a 48Vdc system.

That 90W should be the beginning of a very short transient down to zero watts as the battery and capacitor voltages equalize. My precharge circuit takes about a second to get the inverter voltage to within 0.5V of the battery voltage. My resistor is way undersized compared to this one, and it...

Your inverter has big capacitors that need to be charged. This takes a small amount of energy, but without a pre-charge resistor it happens really fast which means a very high current; hundreds or thousands of amps. That high current can cause battery BMS’s to trip because it looks like a short...

Making hydrogen out of water with electricity is really easy and definitely DIY-able: Storing hydrogen in a compact space is pretty hard. Ammonia is not particularly safe stuff to store. You're thinking of household aqueous ammonia, which is mostly water with some ammonia dissolved in it...

There's nothing wrong with your cells, and they haven't 'failed'. Your battery is out of balance and that can make it behave as though it has reduced capacity. Balance the cells and you'll get full capacity back. Install an active balancer that only balances above 3.42V, and you'll likely...

The most likely culprits are a N-G bonding issue or a grounding issue. Furnaces run a bunch of checks before they’ll ignite the fire and if any of them fail, they won’t do it. Your furnace is likely giving you an error code if it isn’t starting. Check out what it’s telling you. As for the N-G...

I won’t speak for all of them, but my particular AiO is not like this. The switch turns off the inverter, but leaves the MPPT charge controller active. My impression is that most of the AiO’s are like this.

Maybe this would be possible with some programmed logic and heavy-duty switches. Something like run off the 15's only below 48V (3V/cell on the 16s), run off both between 48V and 51.75V (3.45V/cell on the 15s), and the 16's only above 51.75, with the switch to 'both' only occurring when...

The spark is from a very large inrush of current that charges a bank of capacitors in the inverter(s). You should have a switch of some sort between the batteries and the inverters anyway, just wire a precharge circuit on it. Just search for 'precharge' on the forum and you'll find all kinds...

The Victron 100/20 would be a good option. You can also use Victron's tool to check if your Voc and Vmp are going to stay in usable ranges at the temperatures you want to use them. You can't exceed Voc in the coldest case, and you also want to make sure you have high enough Vmp for your...

Science? I don’t know that anyone’s saying to actually only charge your cells to 3.4V. But it’s good to know that if you did 3.45V or 3.5V, you’re still going to get full usable capacity.

It sounds like either: 1. You didn’t top balance your cells. In that case your described behavior is exactly what would be expected. One cell get full first and its voltage increases and triggers OVP. OR 2. Your BMS is getting bad voltage readings. I don’t have a clue what your second-last...

Adam is right that the genny runs the loads. This is true of my AiO, and might be true of this one as well: They can either be inverters (DC - to - AC) or converters (AC - to - DC), but not both at the same time. So in 'converter' mode, when AC is charging the battery, it must also power the...

I think so far everyone else has been too nice about this question. I'll be a little more blunt: This is a bad idea. Using a fan to drive a turbine and expecting to get a net gain in power just isn't going to happen. The largest energy savings by far would be to just turn off the fan that's...

You should expect them to sync to the same state of charge at the top (as you note), and at the bottom, i.e. above and below the flat parts of the curve. But in the flat region, minor differences in the batteries, even if they're as identical as is possible (same connections, matched cells of...

I wouldn’t be worried about this. Two LFP packs in parallel shouldn’t necessarily be expected to follow the same SoC except at the very top and very bottom. The packs will be slightly different, the connections will be slightly different (no matter how hard you might try to get the same, the...

You’re a little confused on some terminology, I think. I’m guessing you have 12 LFP cells and you’re looking to make one or more 12V batteries using all 12 cells, right? You can do this as 3 separate battery with four cells in series each, that would be three 4s batteries. You could do it that...

There's a discussion of semantics here that I'm definitely not interested in having. But the at the very least, the BMS shouldn't control charging (with the exception of BMS's that communicate directly with inverters, but that's not the topic of discussion here). The BMS is more like the...

As a general rule, the most economical solution is to have the highest voltage run the longest distance. In this case that's going to be your PV, which can run up to 500 Vdc. Also, transmission losses for PV aren't as big of a deal as they are for your usable ac power. You would want to limit...

I wouldn’t parallel a flooded battery bank with a LFP bank.

Yeah, as above: what is high voltage to you? I also run 48V nominal and I think it was the right choice. I see lots of people on the forum struggling with massive cabling for 12V systems that require hundreds of amps and I’m glad I’ve avoided that.

For Victron SCC's, connecting to the battery before the PV is most important for the first time the device is connected so that it can automatically detect the battery system voltage. Your Li-time SCC can operate on 12V or 24V systems, so it may have a similar limitation. I don't recall ever...

You might get some Voltage readings that are a little off on cell #1 under load because there’s some resistance between the B- terminal and the negative terminal of battery 1. I doubt it would make a big difference except under large currents, but that difference is presumably the reason why...

I still wouldn't recommend it. But if you must: dress for welding. Welding mask for your head, and thick leather covering everything else. And do it outdoors on a surface that isn't flammable.