Most reacted posts

OP here with a quick end of story update. 1.Credit card finalized disputed amount in my favor. 2. Seller wants me to ship the cells back to them. 3. Seller agreed to pay for the return shipping. If it wasn't for my credit card I'd be screwed. End of the story.

I'm sure they have 10 capable shops along the route batteries take from manufacturer to their warehouse. I think my batch was done on the truck buy some dude with a spot welder powdered off the same battery he was welding. While in transit.

this seems a bit dangerous if the wire "fuses" that is a failure with some high temperature (copper melting) and not a lot of control / predictability on where exactly it is happening. will some nearby plastic catch fire ? will something else happen? call me a control freak, but I want to be...

In this situation the right tool might have been visa card. We shall see.

Hi Steve, I've just assembled a pack with the same exact JK BMS It did start up a couple of times initially, connected to phone app etc. Then it would "partially" turn on - show 38V instead of 57V (this is with 17 fully charged cells) The last thing it did was "turn on" to 38V blink for a few...

But I want my money back ?

This is true I've not seen this happen. In my defense, the "silicone" wire I got from amazon has the insulation melting during my clumsy soldering. The wires that came w. JK BMS do seem to hold up better during soldering (while I was attaching those inline fuses yesterday :D ). While you are...

I've seen real professors from real universities give real lectures (brilliantly) on YouTube. There are some very entertaining professionals on YouTube. But figuring out which are entertainers and which are professors, now that could be a career. :)

Call me paranoid but I'm building a concrete "cabinet" outside, next to garage wall. Even with LiFePo4 and the best BMS and fuses etc. I want to be sure that my power wall is safer than Tesla's. Cinder blocks are cheap, rebar is cheap, cement is cheap. Pretty much everything is cheap compared...

Here is a little design that makes me less anxious around all these kWhs Happy to share stl file, takes about 10min to 3d print one. Depending on your printing skills you might have to run M6 tap before using... I did ? https://www.thingiverse.com/thing:5987594 - STL file here

To late to change things, but I welcome any suggestions anyway! Dimensions are approximately 32"x20"x15" basically should fit 8x2 cells + the bms, contactor and esp8266 for extra temp monitoring etc 4" bottom 2.5"walls and lid. Hardie backer board for leave-in-form, concrete filler. Liquid tight...

Right, when you compress and connect your cells are you going to use flexible bus bars?

Thanks, this is the plan. 18650batteries sell them for +$500 for the shipped 16cells vs these, but they have the beefy terminals and are allegedly better with test reports etc. It's a shame because the ones I could test did have around 283Ah and 915Wh. I'm going back to woodworking while this...

I'm not an expert, just read this somewhere that aluminum does not spot weld. Maybe it does in some specific situations. But batteries in that vid are not aluminum. And the thickness of material that is attached to the battery is a lot less substantial in the video. Spot welding is much simpler...

Cool! But that's not the 6048 is it?

Because they said it's laser welded ?

That was me on the other thread, I'll double post the test results probably end of this week. As for thread depth, I don't remember where that doc is, but 2.5mm was specified as the max drilling depth. Not a great option either.

Op here with quick update. The seller emailed several weeks after dispute was filled. They proposed small credit for failed ones. But eventually agreed to refund the whole thing. I had to photograph each qr code etc. Still waiting for them to provide shipping. Now who do I buy cells from and 16...

nah, not mkay 48v is a nominal "label" "lower amps" is imprecise enough to be misleading lower amp-hours (capacity) is accurate but also higher running amps - by ~6% -> more wire and bms heating etc some inverters are capable up to 60V and are labeled a "48V" system I am using 17s packs...

Exactly

Thanks, this is great to know. I absolutely agree on all your points. and the wires I'm going to use are 2/0 (because overbuilding and worried more about robustness than expense) they are very fine-stranded But trying to fit everything in compactly the wires are only about 4" long. Together 8"...

calling the number on their website produced a very startling effect: "What number are you calling? You called a wrong number." and no responses to email from Dec 17th. YMMV

Grid was down due to storm and the batteries at 7% so I was changing every imaginable menu. In the end I hooked up the generator to AC input. That worked. It is unacceptable as a regular practice but addressed the emergency need. You have to be really really sure you have grid disconnected. And...

Op called ? The dude in the phone said "wrong number" Op emailed, then after 2 days used website chat window got "automated" reply over email after 24 hrs saying "we'll get back to you". And if I have to ship them back, I'd be happy to. At their expense. Should not be too bad, from/to California.

Good point. Yeah location makes a huge difference with the mayhem on the news today. It doesn't go below 48F at night where I am. Saw some frost on roofs few mornings ago but 55+ during the day. It also doesn't get above 80F so if all the connections are reasonable it shouldn't need cooling...

the welds can not be flat enough, at least on the cells that I have i agree that the surface around the stud is very small but I would be much more concerned with flatness. could you post a picture of what the surface looks like? (the one that the bar is sitting on after the mods)

Some rely on government regulations, some don't give a ...t, some read forums to learn... Absence of confirmed stories doesn't make me feel confident enough. All this stuff is too new. If there's a precaution that I can take and it means only a marginal effort and cost, I do.

I did have these errors (I think ... something about grid frequency) on startup only. Also "cold start" from battery (no grid) would cause BMS to go into "short circuit" for 60seconds twice. I guess capacitors had to be charged, after that cold start would work and I could connect the grid. Also...

Very cool epoxy only $44 on Amazon. This best version has 5.4x10-4 ohm/cm resistivity. At 200A and 1mm thickness and 1square cm area the connection would dissipate 2W. The 8331 "economical" version would dissipate 28W. Definitely too much. Editing the arithmetic: I suspect it is not too...

thank you for your reply I just found this thread https://diysolarforum.com/threads/very-confused-need-help-with-ac-coupling-ip6048.60815/ which with your answer together looks like the thing I want might work