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I’ve been operating submersible well pumps for more than four decades. I’ve installed, repaired, and replaced many pumps. The reason for this post is to encourage anyone operating, or planning to operate a submersible pump on solar power, of the significant benefits of powering the pump with...

Bazaar, I echo your sound advice. I’ve seen that cell voltage deviation can be reduced significantly by careful cleaning of the terminals, bus bars, and wire terminal lugs - using a Scotch-Bright pad. When I have a cell that looks to be out of balance, my first step now is to un-do the...

This is a modification to my solar charge controllers, for charging Lithium batteries, that I haven’t seen mentioned elsewhere. My SCC’s are Outback Solar FM80’s, but in reading the manuals for other similar charge controllers, such as the Victron “SmartSolar”, the Schneider “Context”, and the...

I thought I would offer up my simple practice for insulating bus bars and battery terminals that I haven’t seen mentioned before. I use a small-diameter bicycle inner tube, cut into lengths a bit longer than the length of the bus bar. i cut back each end of The “under-side” of the rubber tube...

Hello all ..... At first, I was skeptical about this idea of using springs for pack compression, but after reading all of this discussion, and thinking about it a lot, I concluded that it was the best affordable means of compression for my three new 8S packs of 280 amp-hour cells. I finished...

While the cost of brand new LiFePo4 batteries has been dropping, Tesla just announced a price increase for their 13.5 kWh Powerwall. This new cost will be $7500 for the Powerwall, plus $1,000 for the Gateway controller, plus $3500 for installation. Tesla is said to be selling all of these that...

Thank you very much for sharing. I'm sorry this difficulty, but very glad the results were not worse. Even though we don't know the cause for certain, your experience impresses on me the potential hazard represented by the massive kWh stored in my battery bank. It speaks to the need for all...

K8MEJ: Like you, I wanted flexible cell interconnects. I wanted them to allow for spring-compressed cell expansion. i prefer to only use tinned copper, so the rather costly, and only slightly flexible, non-tinned CALB bus bars don’t interest me. Looking at tinned copper braid, I found that...

That statement is way too dismissive of the skill and intelligence of many dedicated membets of this forum. Good empirical work has been done that makes it much more than guess and speculation. We might not have access to expensive strain gauges and pressure sensors, but this is a community...

It is very difficult to consistently charge lithium batteries to less-than-full charge by carefully choosing Absorption/Float voltages and tail currents, if your loads and solar radiation are not constant. And those are not constant for most of us. For months I tried to find a satisfactory set...

I have three of the Overkill BMS incorporated into my large off-grid home system, built with Outback Power Inverters and CC‘s. But I don’t pass any charge, or discharge, current through the BMS for several reasons: 1. Even though it is rated for 100-amps, the heat it dissipates is wasted...

Of course, understanding how they inter-relate is very useful. Ohm’s Law, which goes back to the early 1800’s, is the algebraic expression that exactly describes how voltage, current, and resistance relate to each other. Don’t know how that question relates, but our culture, and lists of...

While the MG Chem silver paste that I started using a year ago is working VERY well for me when applied as the thinnest possible film after careful cleaning, I am always open to hearing about something better. Thanks for the pointer, noenegdod. I’ve ordered a tube of the Chemtronics Silver...

Why not use both banks, but not simultaneously? Wire them through separate circuit breakers, to connect either bank to the system, one or the other, with the appropriate charging protocol set up and selected, for the different chemistries. Then you could also add to the lithium bank later...

Tesla has already placed almost 2,000 Starlink satellites in low earth orbit. The FCC has, so far, permitted them to emplace 12,000 of the things. Starlink is seeking permits to launch another 30,000 satellites beyond those 12,000. Why is there no clamor of objection? Elon Musk’s hubris and...

Sorry to read of your troubles. Thanks for sharing. It seems like you have been patient and reasonable. I’m also waiting on a refund from Michael. I’m sure that I will get it once he digs out from under all of this mess, but his inability to keep up with communication has resulted in a lot...

This is probably a simple wiring error, but can you give us more information? What is the rating of each panel? I assume all five panels are wired in parallel? Are they going through some kind of combiner box? Are you sure that the wiring is correct? How are you measuring the 0.8 amps? Can you...

For my large home solar battery banks, I also use control relays, but in a bit different manner, to preclude the need for a high-capacity BMS. I have two of the smallest JCB smart BMS’s (30 amps rating, purchased from the JCB store on AliExpress for only $40 each), connected to each of my large...

LOL ... That’s the nature of any DIY community .... lots of different ideas about THE best way ... Different applications, different budgets, different priorities, different critical thinking skills. Read more posts and perhaps get more confused. But there ARE a lot of knowledgeable folks...

I see nobody replied to your post. Maybe you already selected your solution, but . . . Fuses are only voltage sensitive with respect to maximum voltage. A 58-volt rated fuse is appropriate for 12, 24, or 48 volts, anything up to 58 volts, and probably quite a bit over 58 volts. The potential...

An interesting video. Desmet’s propositions seem credible. Those who have not watched the video, but react negatively are, I suspect, presuming Desmet is pushing some conspiracy theory. He is not. He is attempting to describe a theory of human behavior. The moderator tries to goad him into...

Your concerns are quite legitimate, in my experience. WD40 is definitely not approprate to improve conductivity. It is good a good lubricant for cutting and tapping aluminum, but not as a coating between conductors. My cells, at my request, came with the 6mm threaded terminal holes. After...

We all depend on a LOT of electrical connections. There are a many mentions here of ‘conductive grease‘ related to connections, especially high current battery terminal connections. Tom Rauch, ham call W8JI, is an RF engineer, and one of the most respected antenna experts in industry. He has...

Very much agree. But a big part of my satisfaction as a DIY’er is when I can build it BETTER than the commercial equivalent, for significantly lower cost, without getting crazy about it. This is often possible because I don’t need to mark up raw materials, don’t have to pay for my labor, and...

Using any spring-based solution to maintain pressure, and with springs of any reasonable length, pressure most definitely will change with SOC. Only something like a pressure-compensating hydraulic fixture would allow constant pressure over a range of expansion/contraction. Of course there is...

In case anyone is interested in Home Automation: Several months ago I decided to dip into Home Automation in a bigger way. I was motivated by a desire to provide my wife with a “panic switch” that would turn on all outside lights and some interior lights. We live in the country, fairly...

Welcome Dannyp11993 .... With assist from tons of education that came from the decades (centuries?) of combined experience on this forum, I put a large DIY lithium pack in daily service more than 3 months ago. After operating lead-acid AGM for many years, I am thrilled with performance and the...

No doubt that Overkill Solar offers a good product, fast shipping, good service, and a great warranty. And they deserve to make a profit for what they deliver. The BMS they sell are made by JBD, in China. I own three of them from Overkill, and they have been great. However, if funds are...

Here are a couple of photos. Not very technical or pretty, and not much to see. But this allows me to worry less about some metal object falling of the batteries. Just be careful not to pinch the rubber between the bus bar and the terminal.

1. There is no significant difference between wiring the positive terminals with either a single wire, or with a pair of smaller wires having the same ampacity. There are subtle differences, such as needing twice the number of terminal lugs, and needing to maintain twice as many connections...

A good choice, I did the same thing, for the same reason .... because I was also new to every BMS.

There will still be internal pressure, but the sides are tops are much more constrained by the shape of the cells and their smaller surface area. Also, it is separation or delamination of the internal cell insulating layers, or damage to those layers, that is generally thought to be the mode of...

Hedges .... You make an excellent point here regarding the importance of planarity (flatness for most of us) between lugs and bus bars. I agree completely. This whole debate regarding Noalox, or other anti-corrosion compounds, between bare copper connections is very contentious, even within...

The first photo below is the output waveform from my Outback VFX3624 inverters when not powering a VFD. The second photo is the waveform of input power being supplied to the VFD from the Outback inverters. While the audio frequency ringing imposed on the waveform has never caused any problems...

No, the battery will not pull down the 19.5-volt laptop supply. The supply will regulate output voltage to 19.5 volts, up to its rated capacity. If you connect it to a low impedance load that would draw more than the rated capacity of the supply, the power supply will go into a self-protect...

You are correct. It is valuable to have a solid understanding of “Ohm’s Law” which says “E = I x R”, and which means that the voltage measured between any two “nodes” in a circuit is equal to the current flowing between those nodes, multiplied by the resistance (in ohms) between those two...

I think your idea to use the BMS to manage charging could work. However, I suggest using the BMS “Batt Over Voltage”, and “Batt Under Voltage” parameters to control charging, rather the “Cell“ over and under voltage parameters. This would allow you to keep the “Cell” parameters set and active...

Not absolutely necessary, but I think a good practice. The inductor (which the industry calls a “line reactor”) is primarily intended to suppress RFI (radio frequency interference) from affecting nearby devices, especially for long runs of wire, as to a well head. The RFI is an artifact of the...

Is anyone using a programmable battery monitor that they can recommend for reliability and accuracy? By programmable, I mean: 1. AH indication is scalable to the Outback Power shunt that I already have in place. (50mv = 500 amps) 2. “Charged” and “Discharged” alarm relay trip points are...

Nice to hear of progress to any kind of manufacturing being created in the in the USA. The largest lithium mine in the US is located north of Reno, Nevada at the site of a former US Gypsum gypsum mining facility.

A VFD that puts out 240-volt 3-phase power, does not actually require a split phase input. It only requires 240-volt single phase AC. If you have a heafty enough supply, it would be possible to feed 120-volt single phase into either a conventional 2:1 transformer, or a somewhat less expensive...

I looked into those braided copper straps a couple years ago as a possible solution. My conclusion was that they are significantly over-rated by Galco. For example 16.4 mm^2 is about the same cross sectional area as 5 AWG copper wire at about 33,000 circular mils. So, the current capacity is...

My Outback Power SCC‘s also do not have an input that can be used to properly switch them off while connected to solar panels. To overcome this with my large lithium battery bank, I am using the RTS input with one value of fixed resistance fully shut the SCC down in case of a BMS over-voltage...

Hedges ... good additional information. Thank you. I have only ever used an Outback VFX series inverters with capacity that is almost 4x the full load power consumption of the pump motor. I have seen cautions that indicate that a VFD can cause problems for a power supplying inverter that is...

Good question .... I do not rely on the BMS for this function. My Outback Power monitoring system already had that function, plus kWh and amp-hour metering, built in. Plus my sources and loads are very conservatively rated, so that I probably will never get close to over-current In either...

I haven’t been to KFC in years. Do these cost more, or less, than “real” chicken nuggets? Too bad there is so much lack of agreement and so much unclarity on what foods are most healthful. Clarity about that would go a long way in guiding this kind of crap, err, questionable food products.

Ahhhh .... complicated subject, not knowing your background, so where to begin? Most such power supplies are “switching” or “switch-mode” power supplies. Google either of those terms for lots of good explanations. Those are in contrast to the other broad category of “linear” power supplies.

An unusual but interesting idea. Yes, you could do that. The SCC work work just the same when supplied by any DC source that is within acceptable voltage and current parameters. Certain power supplies might get fussy when connected in series or parallel, but many times that will work.

The bench top supply is not vastly different, but it gives easy control over the output voltage. That is, if you want to feed 3.65 volts into your cells, turn the knob until the output is set to 3.65 volts (as confirmed with your pretty-accurate digital volt meter). Most bench top supplies...

Thanks for the recommendation, snoobler. I considered a whole bunch of different battery monitors. None will do everything I was hoping for, but partially on your recommendation, I ordered a Victron BMV-712. It comes pretty close, and I’m hoping that the somewhat premium price will reflect in...

i can understand your confusion. Whoever, from Windy Nation, wrote that note is not the best advisor. To reference “100Ah of charge” is poor practice. The meaning of 100Ah is only useful in the context of the system voltage. Far better would be to reference watt-hours, or kilowatt-hours, of...

Fortunately, it isn‘t necessary to buy a Victron SCC, nor is it necessary to add relays to the solar input. (This is fortunate because I bought my Outback SCC’s about 11 years ago, before anyone was using lithium for solar). The control system I’m using in this way is not complicated at all...

Congratulations. Nice work.

I’m sure your design engineers knew what they were doing, but as you say, disposable batteries are one thing .... I didn’t mean to imply that the scheme used by Outback Power engineers is perfect for Lithium batteries. This charge controller was designed more than 10 years ago, for lead-acid...

Snoobler, Thanks very much for your summary. It is nicely concise compared to my wordy explanation! LOL You are surely correct about the Victron unit. My familiarity is only from a not-so-careful reading of the user manual. Of course, a disadvantage of using the battery monitor rely to...

About 50% SC is what is recommended by most forum posters. However, I have seen no laboratory data to support this. From what I have seen, there is one "application notes" paper, from one manufacturer, that suggests this, with no supporting data. The real testing by the competent manufacturing...

Come on ... let’s be thoughtful about this. While I agree with you that compression is probably worthwhile for lithium batteries that are used normally/regularly, and while I have my cells under carefully considered and chosen spring compression, the original poster asked this question because...

No, the DC-DC converter does not need to be limited in capacity. A converter rated at 20 amps maximum would be fine. That is just the maximum amperage cab be drawn from the device without damage. It is a bit like driving a muscle car with a big engine. You have that potential power under the...

GVSolar .... thanks. This unit looks VERY similar in capability to the VICTRON unit for only 60% of the cost. If it had TWO relay outputs, it would be even more attractive. My son-in-law is going to need something like this, so we will consider it seriously when he is ready to buy something.

Paul, How to explain within this sometimes cumbersome teaching forum? I‘m not sure, but I rather suspect the notion of a “hot leg” is complicating your thinking. We are used to that form of thinking because our power grid supply is constructed to make it easy for us to access both 120 and 240...

Welcome to the forum. Electrically, the order of devices in an open circuit doesn’t make any difference. However some arrangements are somewhat more safe than others. It is nominally better to make a fuse your first device, and a cutoff switch the second device. This allows you to perform...

I like EVERYTHING at Chick-Fil-A, but the strips are especially tasty.