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I guess I have a problem when the line of demarcation goes from "You have to do it safely" to "We aren't going to let you do it yourself." The NEC definitely exists for good reason. If you look at electrical installations from 60 to 100 years ago, they were just accidents waiting to happen...

I think this is a really valuable video, not so much to bash Chins or Ganfeng, but rather to emphasize that just because it says "solid state" doesn't mean that it is safe. They probably do have some solid state component in the battery, and it definitely had a higher volumetric energy density...

Don't think I'll be ordering. I'm not a fan of connecting things to high power equipment with spring terminals.

You might be thinking of the way lithium metal reacts with water violently to form lithium hydroxide and releases hydrogen gas in the process, which will usually self ignite from the heat of reaction. With a lithium ion battery fire, most of the heat is coming from the flammable electrolyte...

I signed up for the free access to the NFPA codes at https://www.nfpa.org/Codes-and-Standards/All-Codes-and-Standards/Free-access I think the result of these changes will largely depend upon your code enforcement AHJ. The language in article 690 defines the parts of a photovoltaic system and...

Perception is a funny thing. My mom used to always make sure the toaster on the kitchen counter was unplugged if we were leaving the house in the morning, because it "might catch on fire". However, she never gave a second thought to the the pressurized natural gas line in the basement with a...

This is interesting news to me. I hadn't heard of utilities implementing demand based charges on residential customers. I wonder why this was chosen instead of time-of-use rates. The stated goal of both systems is to minimize the amount of generation capacity that has to be installed for peak...

I do have some experience with an LG heat pump dryer. I purchased one last year as part of a long term plan to reduce air leakage of my house. I wanted to get rid of appliances that used conditioned air from inside the house and then dumped it outside. I got rid of my traditional resistance...

Have you looked at how municipal code is written? It usually defines who gets the final say on interpretation. It is never the property owner. Now, you could go fight them in court, but it is an up hill battle. For the original poster's case, the interpretation of what a 'structure' is will...

I was the youngest. I may not have been the favorite child, but I can guarantee I was the favorite son. :sneaky: Or perhaps I just had the problem of over-thinking trivial things. On the other hand, a few years ago I was home at about 8am when I heard a loud THUD and felt the house shudder...

So the question in my mind is how much of the loss from 176 Ah to 155 Ah is just the reduced capacity of using the batteries at a low temperature and how much is permanent degradation from the damaging effects of charging at low temperature. This will be interesting.

Here is a link to the data sheet for the SIND 06 610, since it is the one that looked superior in his video. https://www.trojanbattery.com/pdf/datasheets/SIND_06_610_DS.pdf Couple of things that jump out right away that he didn't talk about. First, the Peukert effect, ie loss of capacity due...

There are insulated boxes, and then there are INSULATED boxes. The answer to your question is calculable if you know the combined square footage of surface area of all sides of your box, the temperature difference you want to maintain, and the R-value of your insulation. This assumes you have...

I'm going to stick up for the Volt a bit here, both in terms of concept and implementation. I've had two of them, a first generation 2012 and a second generation 2017. My daughter now has the 2012. I got the 2017 because I wanted the longer electric range and adaptive cruise control. Where...

At this point it may be a bit redundant, but since I was only able to make this purchase because others shared their experiences, I thought I would add my purchase experience with Jenny at Docan to the thread. I have purchased two batches of 36 EVE 304ah cells from Docan. The first was ordered...

I've been looking forward to this test with interest because I've been considering how to design a solar shed for Midwest winters. Lag in cooling of the thermal mass of the batteries along with the speed of heating during low temperature charging are important for determining how cold I can...

I just ordered four 16S battery boxes with JK BMS and Screens from Luyuan yesterday. DDP Shipping to Nebraska was $375 None of the pricing information on Alibaba is set until you make an inquiry and get a quote. Especially with the shipping cost. Edited to add that when asking for a quote, be...

I watched a 'Fully Charged Show' video today that pointed out an interesting contradiction in "cost sharing" that is happening in Great Britain. Admittedly they have far more options for how you pay for power, but my local utility has a similar 'community solar' program that gave me pause for...

Wow, you are a brave soul; asking for error correction immediately after referencing pedantry. The result is replies full of information that is absolutely useless from people such as my self. Gravity - not a force, but rather a warp in space-time caused by mass that results in a bend in the...

The only way to resolve the question is to call your county code enforcement office and ask them. The thing that will matter in the end, is not exactly what the code says, but exactly how they interpret the code.

I found the table below at bruker.com. They make a product called Cuponal, which is copper clad aluminum bar stock. The important bit from this table is the first two columns by M6. So they are recommending 4.5 to 5.5 Nm for optimal connection between two pieces of their bar stock when using M6...

Just watched the review video here. For obvious reason, I think the discussion of the video belongs in this section. I checked out the Ganfeng cell data sheet, and noticed that in their safety testing, there is no puncture test nor any guarantee that it can be punctured and not combust. It...

When dealing with vendors, it is important to realize that Grade 'A' or Grade 'B' has no standard definition. The manufacturers sell batteries that make the grade for vehicle use, which does have government mandated standards even in China. The ones that don't meet the requirements of the EV...

Solar energy, as in raw energy emitted by the sun, is probably the least 'green' in terms of the ecology of earth. If the sun were left unchecked, its emissions of highly charged fast moving particles would strip away the atmosphere, and its high energy electromagnetic radiation would break...

I did try to look a Docan's website before I purchased, but didn't really find very helpful. In the U.S., the expectation is that you should be able to go to a website, see a product description and a price, figure out your shipping cost and place an order without human interaction. When...

Here is the section of an EVE LiFePO4 spec sheet dealing with temperature. So, you can discharge the battery cells as low as -35°C (-31°F), but they don't want them stored long term below -20°C (-4°F). An of course they are not supposed to be charged below freezing. It really becomes a...

The old adage: "Good fences make good neighbors"

If we define words arbitrarily, our ability to communicate will be nominal. :)

It sounds like they removed the phrase that section 706 only applies to DC systems greater than 60 volts and replaced it with 'greater than 1kwh', and added the listing requirement, and made it applicable to stationary and mobile installations. That would mean that if you put two Battleborn...

Actually, the word nominal is super frustrating in kind of a funny way. Some of the possible definitions are: existing or being something in name or form only (ie. "He's the nominal governor, but has no real power') relating to a designated or theoretical size that may vary from the actual...

The other interesting data points to look at are the individual cell voltages when the pack reaches its low cut-off point. This will give you an idea of how closely matched in capacity the cells are. Also, in this post I gave results of measuring my battery with different meters that I have...

I'll be the one to ask the potentially dumb question here. It sounds like you are using information from the inverter to decide the state of charge of the batteries. How does the inverter know the state of charge of each battery that is in series? I don't see voltage sense wires going from...

If you are looking for someone who has been consuming alcohol to help you, I'll do my best. So watt hours give you a rough idea of how much energy is in your battery, and a rough idea of how much power your load will consume. Kinda like saying "I bought a 12 pack of brews for my uncle, and he...

Research Gate had a paper from 2017 that is available for download where they shorted a 160ah and an 8ah LiFePO4 battery. https://www.researchgate.net/publication/316171277_Temperature_Overcharge_and_Short-Circuit_Studies_of_Batteries_used_in_Electric_Vehicles It looks like the current...

I found this article interesting: https://www.sciencedirect.com/science/article/pii/S037877531730839X They shorted out NCM and NCA cells at using different external resistances (unfortunately they did not test any LFP cells). On the most direct shorts, the current chart looked like this...

It is also important to consider the power output at NOPT (Normal Operating Temperature) vs. STC (Standard Test Conditions). I was looking at some Panasonic HIT panels that appeared to be twice as expensive as the cheapest ones, but they only lost .3% per degree Celsius temperature rise, as...

This evening, I ran across this video on the Texas power failures. It is the best thing I've found so far that keeps to a technical explanation and has some interesting charts and graphs.

When I read the datasheet here: If you don't read the intermingled information about screw size, I think it becomes clear that they are talking about the battery pole itself. Since "anti torsion" literally means "resist twisting", it could be written as: Separating the screw thread...

I'm not sure which iCharger model you have looked at. I own the iCharger X8. I can't give you any good comparison with other equipment. However, I did shop around and chose the iCharger because it is sort-of a Swiss army knife of buck / boost charging. It has profiles for many different...

@Sillyputty , Thanks for sharing your misadventure in battery repair, and I'm glad the damage and cleanup wasn't too bad. If I'm ever in this situation, I would probably give it a go, but definitely have it on the list of work that must be done outside, where the smoking remains can be kicked...

So, I watched the entire second video. Near the beginning, he does acknowledge that lead acid batteries require careful operation and regular maintenance if one is going to get the maximum rated life from them. Then he also acknowledges that lithium batteries can endure much longer spans...

Thanks for the well written and detailed evaluation, and the photos of the modifications you made.

I agree this is the best thing to check first. Pictures of your battery might help people make other suggestions. I thought of a couple of things based on mistakes I've seen other people make. First, make sure your batteries sit level with the top of the battery cells even, so that the bus...

I am dumbfounded by the historical attitudes toward home insulation. It is evident that either that generation was so hardy that cold, drafty houses were no big deal, or evidence that the relative cost of energy was really cheap. I purchased an old 700 sq. ft. home that was in terrible shape...

They were probably safety sandals...:rolleyes: I'm thinking the cells are lithium polymer or NMC based on the voltage range in the datasheet. Definitely have an exothermic reaction that releases oxygen to make them burn that fast. Edit: I just took another look at the data sheet, and right at...

Hey Will, I think you might have misunderstood what they meant by the whole "Drill baby, drill!" thing.

If the solar panels are the Mega200 Max panels on Rich Solar's website, they have all of the temperature coefficients in the manual for the solar panels. I attached the manual from their website. A clip of the temperature data is:

If you want some research, there is a paper here called "Overcharge Cycling Effect on the Surface Layers and Crystalline Structure of LiFePO4". From near the end of the paper: And from the conclusion section: So if you got to 7 volts, there is no hope for long term use of the cells. Also...

Thanks for sharing the chart ArthurEld. However, I think it has the 30x3 and 30x5 amperage values switched with one another on the DC side.

Before going into the math on temperature coefficients for you solar panels, and deciding on possible arrangements for them, I wanted to point out the output current limitation on your charge controller. Your charge controller output to the battery is limited to a maximum of 100A. So if you...

People will always assume they know more about any given situation than they actually do. I know this is the case because I assume it to be true.:unsure:

I would say that the data from the BMS rules out an internal short. We know the cell voltage was at 3.34 and then one second later was at 0. Its reasonable to believe that the cell was at least 1/2 charged if the voltage was above 3.3. So 140ah would have had to discharge in one second. That...

I just posted some information I learned about using Loctite on aluminum and stainless steel in another thread here. Essentially, you need to use a primer or it won't properly cure. This is causing issues for some people when it doesn't harden and then oozes out on top of the terminal when the...

From NEC 2020 article 690 - PV system, the ESS doesn't include the inverter From NEC 2020 article 706 - ESS might or might not include the charge controller and inverter I think there are too many design variations to make an all encompassing statement.

Since I've been looking at battery system code in the NEC book for other reasons today, I thought I would chime in with the relevant code section. It says that all it takes to trigger the requirement for insulating battery supports is for a battery case to have a voltage on it. This could...

I don't understand how that chart can be accurate without taking into account the system DC voltage. I didn't see any indication if it was for a 12, 24, or 48 volt system. I think the Blue Sea Circuit wizard calculator is a better tool. The real pain in this sort of system is that the voltage...

Internal resistance of a battery becomes easier to comprehend when you look at the processes in the battery in mechanical terms. This is a valid way to look at it because in the charging and discharging process, you are physically relocating ions from one location in the battery to another...

Me in second grade - "Can I stay up late cause I heard Tommy say school is going to be cancelled tomorrow." Mom - "You can't believe everything you hear." I go to bed and think about that I just HEARD that I can't believe everything I HEAR. A life long struggle begins.... or perhaps more...

Sympathy on the damage to your system. Glad it didn't cause damage to your barn. Thanks for sharing the pictures and the description of what happened. It appears to be a good lesson in being cautious about keeping electrical connections properly insulated from other parts of the system. Am I...

No need to take ourselves too seriously here. I think everyone understands your meaning. It's a fun topic.

@FilterGuy , I agree. Engineers expect that you know what they were thinking when they write a statement. Lawyers expect that you will use their definitions when you read their words Academics are insulted if anyone is able to decipher what they wrote. To help people reading the code book...

I looked up the Edecoa inverter on Amazon to read some reviews. The 2000w pure sine wave version says it has 4000w surge capability, however, the reviews have a split between people who are perfectly happy with it and others who say it let the smoke out. It appears to be a generic chinese...

I believe you stated this backwards. When combining panels, it is best to create strings of panels in series first, In this case it would be two panels in series. Then combine those strings in parallel. The reason for doing it this way is it makes the required fusing of the panels simpler...

@Sillyputty Sorry if it seemed I was poking fun at you or anyone else in the thread. I've just found the communication issues a little entertaining as a casual observer. I think it is a wise policy to never buy batteries from a vendor until they provide a datasheet for what they are selling...

Hi Xhumeka. I also used the iCharger X8 to do a bunch of cell testing. It has a connector on the side to allow for voltage sense wires which can connect directly to the cell terminals and give the voltage at the terminals. This eliminates the voltage drop through the wires carrying the...

I did purchase my 304ah EVE cells from Docan a couple of years ago. I tested all of them and they all exceeded capacity. Life got busy and I only built two 12 volt batteries and the rest of the cells have been sitting. My purchase is so long ago that it can't be used as a gauge of their...

It was entirely configuration of the drains and layout of the room, and where I was willing to run a hose. So esthetics, not physics.

Considering all of the circumstances you outlined yesterday, I really don't have a strong opinion on whether 12v or 24v would be better for your situation. I did happen to see a three year old video by Will Prowse today on this very subject. When it comes to inverter efficiency, I don't...

Economic advantage will nearly always take priority over political or ethical motivations in the world that we live in. For that reason, trade with China will remain available. I think you may be worried about sanctions against China causing trade to be interrupted they way it has been with...

Since you converted the temperature to °C, I think you have to also convert the coefficient. The coefficient is -0.29% per °F, and a °C is 9/5 larger than a °F, the coefficient become -0.522% per °C. The end result, using the calculator you suggested is 56.06 volts open circuit. So it...

The other thing to watch out for, especially on electrical components, is resellers who buy cast-off equipment (essentially equipment that failed to pass inspection) from manufacturers and then repackage it and sell it as good. They will have extremely low prices, but the stuff they sell can be...

Based on the visible portion of the encoding, that may be a Data Matrix, and not a QR Code. A QR Code has the concentric square pattern in three of the four corners. In your image, two corners of the code are visible and neither corner has that pattern. I believe it was stated earlier in the...

I didn't see that Steve S. addressed the "parallel shunt" part of your post. Shunts can only measure the current that goes through the shunt, so if you put them in parallel, only part of the current will go through each shunt and neither will provide an indication of the total current.. So if...

@Will Prowse Thanks for following up with the same test on a lithium iron phosphate cell of similar dimensions. I also appreciate the extra notes you put in the video with the temperature response curves and the run-away temperature for each chemistry. And it is also relavant to the question...

Tonight, I got to looking at this paper from NREL that has a lot of math I don't understand. In the paper they are using experimental data to try to create a formula that will predict LiFePO4 cell degradation. They modeled calendar degradation, separate from cycling, and came up with the...

The above is bad advice. @BTR500, you ALWAYS need to contact your utility provider before connecting any power generation equipment to the grid. If you supply voltage to the grid without their permission, you can endanger their workers. Depending upon the country, you may be liable for civil...

This gave me pause for thought also, especially when I saw that in response to the water supply system disaster that followed the power debacle, the authorities issued a 'boil' mandate for tap water. How are people supposed to boil water without electricity or gas unless they have an emergency...

Certainly understood that the loss of capacity is temporary. Lead acid is more likely to sustain damage at high temperatures, not low temperatures. However, the statement about LiFePO4 is not correct. You can discharge it below freezing, but unless specially designed you cannot charge it...

I think my answer to this is that you can't use the torque on the nut compensate for any curvature in your bus bar material. If the bus bar is flat and clean and the terminal is likewise, it won't take much pressure to create a good electrical connection. If the bus bar is trying to spring...

One of the useful things from the chart above is that, while the increase in stress on the battery with temperature is a smooth rise, the increase in stress with state of charge has distinct transitions where the stress rises. They note it in the text as follows and provide an additional graph.

Ha Ha. That made me remember this piece by Al Hess. "If airlines sold paint..."

I've read this new specification sheet for the EVE LF280K battery cell several times, at varying levels of sleep deprivation and alcohol consumption, and I'm just not convinced we are understanding it entirely. (please note that there is a difference in important details on the spec sheets for...

I bought a bunch of 304ah cells from Docan months ago. I've been methodically testing them, one per day since the middle of August. So far so good. I've built one 12 volt battery to use in testing the other cells. I have 14 more cells to go and then I'll post some about the results. So...

@fhorst I noticed that you have wind turbines in your system. I'm not familiar with wind turbine systems, but I have read that they can build up static charges due to the air movement over non conductive surfaces. The shocks you describe sound like static charges more than emf induced...

I've been pondering the best practice for this situation. It seems most people think of the battery as the source of the current in the event of a fault. However, there are three other batteries pushing current into the bus bar, so it actually has a higher available fault current than any...

So you're saying that they mean to say that the maximum charging rate is 13% of the capacity listed for the C20 discharge rate? That yields a more reasonable charging limit, but if that is the case, Trojan has a really poorly worded data sheet. Thanks for letting me know how you calculate it.

Thanks

These lithium iron phosphate cells are usually shipped at about 30% state of charge. Their maximum rate of loss of charge is usually stated on the spec sheet as somewhere around 3% per month, so in shipping they may get down to 20% if they sit somewhere for a long while. If your cells started...

The amount of summer peak demand and winter peak demand issues we see from grid operators in certain parts of the U.S. does not inspire confidence. I think for the EV transition to work well with minimum infrastructure upgrades, electric utilities will have to embrace rate structures that...

Sorry @rmaddy, but Merriam Webster and I disagree with the subject line of this thread: https://www.merriam-webster.com/thesaurus/looses It's the usage that's generally incorrect. Proper use would be a sentence like:

The only exception I see for the ground fault protection requirement in the 2014 code is: So if your solar power is generated on top of a building or is used in a building, you need the ground fault protection.

On this page, https://www.aliexpress.com/item/1005002958135242.html?spm=a2g0s.9042311.0.0.378e4c4dWNGTXR, It specifically states that the JDB 200A BMS is not rated for multiple batteries connected in series.

Maybe he is trying to refer to this, from wikipedia So, I think this is what differentiates Peukert's Law from internal resistance. Internal resistance dissipates some of the battery energy as heat inside the battery and the result is that some of the battery's chemical energy is unavailable...

The dates that come out of the QR code reader are in the order of day/month/year. So all of your cells are from February. The portion of the alpha-numeric characters around the QR code that give the date are C29. C is the year, 2 is the month, and 9 is the day.

I think as far as energy sources that are readily available to individuals, solar is good and getting better by comparison to other sources. And it has the advantage of being able to integrate into our current method of building structures. On a community level, there is a good argument to add...

I spent some time looking through their website. It is important to realize that this is a reseller who is based in China, similar to the other resellers people mention on this forum. They mention having warehouses in various countries, but don't give any physical addresses, so chances are...

In regard to the MG Carbon Paste, it appears that it might be inferior to products like Ox-Gard when it comes to joining dissimilar metals. The Ox-Gard has significant zinc content which helps prevent galvanic corrosion. The MG product appears to rely only on the grease excluding air and the...

@Dzl , The Bay Marine Supply calculator is much more flexible, and intuitive to use (for me anyway). Thanks for pointing it out.

Just to be clear, I'm saying that the shipping cost for all the stuff I ordered was $375. There was an additional processing charge of about $50 added by Alibaba. The actual cost of the products I ordered was $1324. So the total is $1749. I do think that the shipping cost from China for...