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Thanks. I got concerned by this thread: https://diysolarforum.com/threads/aluminum-heat-spreader-in-direct-cell-contact.80384/ but I do think my fears are overblown and there should not be any problem putting the cells directly on top of the aluminum plate, as they do have a thin layer of...

@Horsefly this battery build has served as the inspiration for my own insulated battery box, it's really great. One question - did you add anything between the aluminum heating plate and the cells?

You could try @42OhmsPA ’s trick: https://diysolarforum.com/threads/how-to-connect-the-black-style-jk-bms-with-the-short-b-and-p-leads.82942/post-1076500

Was there any surge protection in front of it? Directly to the south of the tree is a lake -- the land slopes up to the north (the direction that the dish is pointing). There are plenty of trees surrounding it that are taller, but not tall and close enough where I believe they're obstruct the...

I appreciate your pragmatism, @timselectric.

FYI I am doing this @AlaskanNoob. I'm using this POE injector: https://www.amazon.com/dp/B0CQC4321X. I have it hooked up directly to my 48V bus bar through a 4A DC breaker. My battery is set to absorb to 55.2V, which is below the POE maximum of 57V. It's been running for a couple weeks like this...

Thanks for all the feedback folks, this is helpful. Isn’t it though? Starlink is powered by POE coming from my battery, which is bonded to my house ground through the shielded ethernet cable. If the dish is also bonded to the pole, wouldn’t adding a ground rod at the tree create a ground loop...

I've recently installed Starlink at my off-grid cottage, however the number of trees cause a large number of obstructions for the dish. I've seen some videos on Youtube of people mounting their dishes in trees and I think this is my best option. I've reached out to a local arborist who will take...

Another update! A week or so ago, I decided to temporarily assemble my battery at the cottage while I wait for my battery box to be built. This allowed me to complete pretty much all of the DC wiring and get the system up and running. I will probably create another post for my DIY battery once...

I don't think it matters -- unless your negative is grounded: https://electronics.stackexchange.com/questions/445740/does-it-matter-if-a-fuse-is-connected-to-the-negative-or-positive-terminal-of-a

I had cropped the class T fuse out of my original picture. Here's a larger view of my inner battery box that includes it: My fuse is connected directly to the positive cell terminal. This inner wooden box is going inside of an insulated custom fabricated metal enclosure (which is shipping out...

@Skypower it was that picture of your BMS that inspired me to mount my BMS the way that I did! 🙏

I'm in a similar situation as OP and could also benefit from clarification (I'm shining the timselectric bat signal). I have an off grid system with a Victron Multiplus II 48/3000 inverter with the AC out back feeding 120v into a sub panel (6 spaces, 12 circuits). I have a small 2600W floating...

I’m using ones similar to what you linked, with heat shrink. I bought a pack with various sizes, but I think those Wirefy ones should be good.

Designing and building my solar system has pretty much been my primary focus for the past 6 months. I don't feel like I'm ripping through anything lol. I've spent soooo much time going through these forums and learning from everyone here. All the stuff you're mentioning are things that I've also...

I used zip tie mounts that are screwed into the top of the plywood box lid, like these: https://www.amazon.com/dp/B078P8TPPZ. It's nice because it provides a bit of clearance under the BMS. I used these terminal posts: https://www.amazon.com/dp/B0B2LK7KDR, but like I said the bolts were too...

I used two slightly different approaches (based on the lugs I had on hand at the time): on the B- side I crimped each wire to a lug, and on the P- side I put both wires into a 4 AWG lug. Both lugs are on a terminal post. I did have to buy longer bolts for the posts because the ones that came...

If you're using Victron Venus OS and a software dev, I can imagine that you could build something quite elegant with the amount of data available. Basically any data that is displayed on the console UI is available to a custom application. You could have some simple logic that just enables a...

You laugh but look at the number of posts in the Up in smoke section that are caused by bad connections!

Don't read too much into this. It can be increasing resistance, but it may not be significant assuming you're doing it right. For example, do you know why you want to properly torque your connections? Because if you have loose connections that increases the resistance between the connection...

I'm curious about this as well. I just wired up my system and I'm not using fine stranded wire like they recommend. This sounds a bit dramatic to me? I feel like it depends on a few different variables. In my case I have a 48v system with a 150/45 SCC where my PV connection is using 8 gauge...

My point is that everything has resistance. The reason you want to minimize the number of connections in your system is because every time you are connecting something together you are adding more resistance to the system. The reason you might use 2/0 gauge copper wire instead of 20 gauge copper...

It's not exactly like thicker wire though. The two bus bars are not one solid conductor, there will be some small resistance between them. It's just like when you attach two lugs together on a post. In your picture you can see the bottom bus bar is making contact with the breaker and the top one...

I didn't notice that you are stacking two bus bars. I don't think that's necessary and may actually add more resistance. I would just use one. You won't be able to do that with a standard multimeter. I'm using a YR-1035+ battery resistance tester, which you can get on Ali Express for around 50...

I think this should be fine. The resistance of one of the bus bars that came with my LF304 cells is about 0.06 mohm measuring from hole to hole (67mm apart). From that you can calculate the voltage drop at say, 200 amps (V = I * R): 200 * 0.00006 = 0.012 volts. From that, measure power with P =...

Thanks for the reply Skypower! This is exactly it! I haven’t put my system into service yet, but as I measure all of these individual components I’m adding it all up in my head, and it’s not nothing. Yeah, I get this. I'm not even looking for an accurate comparison - more about whether I'm in...

I'm in the process of crimping cables to set up my system and this picture is very helpful as a basis of comparison (assuming those labels on your lugs are what I think they are). @Skypower are those the labels on your lugs and busbars the resistance values of the cables in milliohms? I'm using...

I used a wire nut in my combiner box for one of my arrays to splice 10 (from panels), 8 (to inside) and 14 (SPD) gauge wires together: I'm pretty particular about things as well, but what sold me on using a wire nut versus other methods was watching this Youtube video on splicing larger gauge...

Things are progressing nicely. My battery box design has been completed and is now being manufactured: I made it up to the cottage earlier this week to start mounting and wiring up the system. One of the challenges of upgrading this system is that there is an extremely limited amount of...

I'm building a DIY battery and bought an internal resistance tester on Ali Express to validate the resistance values on my cells. Aside from the battery, I'm assembling a bunch of the components for my install ahead of time, since my install location is nearly 2 hours away. While testing...

The case/rack, bus bars, fuses, cables, switches, terminals. Perhaps most importantly, your time. I enjoy doing this stuff, but if I take my "hourly rate" into account, I have a really, really expensive battery (and overall solar set up), and it's not even done yet!

I can agree with this. I went down the rabbit hole of compression research before deciding like Mattb4 that I'm just not going to bother with it for my DIY battery project. For my use case I don't think it is worth the trouble. I'm not charging and discharging my cells at high C rates. Maybe my...

If you're going from 6S to 3S2P you should probably double check the wire gauge running from your panels to make sure it can handle 2x the current.

I'm also planning on using an aluminum plate as a heat spreader for my DIY battery box, also using EVE 304 cells. Under what conditions would you expect the shell cases to short? The cell spec sheet says: I understand this to mean that each cell is wrapped with 0.11mm of polyethylene...

I realized when I woke up this morning that having so many resistors close to the NTE-DTO60 in the small case enclosure that they would generate enough heat to prematurely open the switch. As an alternative, I used a single 47k resistor. This should only need to dissipate 0.06W of power (and...