Check the Buying Options tab to find cheaper versions of it, example
https://www.amazon.com/dp/B0CHYN2LBP
Iāve never even noticed the tab you are talking about, where is it at on the page? I did however see this item I thought after comparing the one I got was more suited Probably because charging was in the name description
It only shows up for certain items if Amazon thinks there are similar items at a better price. When I clicked your link there was no price shown and there were choices in the upper right saying āPrice higher than typicalā and a button that said āSee all buying optionsā.
Doing some repairs on an old 7 chambered loanstar ss and found some bad nickel on two of the sanyo 20700 p groups and thought id share:
The individual cells arenāt glued or anything and just sit in the spacers. Got flex/vibration breaks in the nickel but caught it early as all the cells test well.
Lots of sharp corners and mid solder work, but admittedly the solder is probably just fine as this battery and board have north of 4000 miles on it or likely more based on how much the owner rides. (Not the first battery repair on this pack though) one nice thing is 21700 cells are so good now a new custom battery at lower cell counts will likely keep or improve the range on this boat. Good times.
Just a little show and tell.
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I continue to be baffled and disgusted that LaCroix got away with building packs like this for so long. And then they āimprovedā by switching to Chi building their packs 
I wonder how many fires they had.
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it doesnāt inspire much confidence in what I didnāt see inspecting this one group. This whole pack is getting a tear down and inspection with an enclosure swap shortly - if i touch it it has to get fixed right. can o worms we got here but it is all good. better to catch it early and fix it than to get on the wrong side of the fuck around and find out seesaw.
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Oh man thatās from factory?!?!
That seems pretty bad, seems like the only way to do it properly would be to glue every pack corrrectly to prevent further breakages.
I have learned a lot from everyone here but I want to send appreciation to rbe motion and pavel for the videos they have posted and taking the time to do it right with instructional purposes for people like meā¦ my first build is a ticking time bomb but I was able to come close to making a second. I just realized last night my spot welder wouldnāt work for the .3mm nickel so Amazon was super thoughtful and generous enough to send me a brand new one
For 230$
hopefully it works
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My lipos have arrived, pre crimped JSTs should be here on Saturday.
I have 0 experience doing literally anything with batteries so Iām hoping to take it slow and ask people to check my work at each step.
Iām going to ping a couple battery builders that have been patient enough to help me in the past @BenjaminF @Pecos @jack.luis
My goal is to setup a BMS to charge my lipo pack, preferably without soldering anything live. The pack consists of 2 cheapo turnigy 6s, 10AH lipo batteries in series. As well as a 12s 20A LLT BMS.
Hereās what Iām currently working with:
BMS underneath the battery. Battery weight supported by more foam. (Planning to add even more foam to keep the bottom flat and support every edge of the lipo pack)
I did my best to route the BMS wires without any overlap or potential for rubbing but I have some concerns here:
The wires coming out of the lipo and into the balance harness are varying lengths that I couldnāt find a way to get them to lay completely flat, is this something to be worried about and spend more time on? I plan to place another piece of foam along the front end where all the wires come out from the lipo+BMS but Iām unsure if thatās enough protection for the wires.
I attempted a bridge with kapton tape where the BMS wires interfere with the lipo balance wires, the bridge I attempted is about 2mm too narrow to cover all of the balance wires.
Should I undo all of this and start over or am I on the right track?
Edit: Itās also probably worth asking if thereās any risk to my over-usage of foam, I have plenty of unused space in the enclosure this is going in but Iām not sure if Iām missing something.
if you cant get them to lay flat so you can tape them down tight - i am of the opinion that loose at the crosses is better than tightly wrapped. let the slack keep them from rubbing or put a dab of silicone or hotglue on them to keep them from moving/rubbing. they look like good quality wires which helps alleviate worry about them wearing and shorting. cheap wire kills more balance leads than uninsulated crosses in my limited experience. that super hard fine stranded stuff seems to give no fucks how you run it, the nice soft silicone is prone to physical damage but not vibration, the spongy plastic crap on some bms you can strip with a fingernail just likes to fail.
foam is insulation, so de-rate your charging a bit, that bms heatsink needs to move the heat out and wrapped in foam it will get to its thermal limits faster if there isnāt anywhere for the heat to go to. probably not a big deal but might be worth looking at if you see the temps go up and it throttles the charge current. a pretty safe fuck around - try it and see what it likes as you monitor the first couple charge cycles.
one nice thing about making a pack like this is it is easy to check on and see how its doing - just pop it out and inspect it real quick until you see how it does.
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I need help please. Idk what I have done wrong but I feel like itās something possibly I should have started on a different lead but Iām am having. Issues overheating the bms one bms I had first was messed up but the wire fizzled idk it looked good up until then and of course I buried it in glue fuck me
double tripple quadruple check the bms wiring?
post pics that allow someone to try to validate wiring for you?
what do yo umean by fizzled? what exactly were you doing when that happened?
I was hot gluing the sensor wire down it was the last one but I had the glue gun close in there kind of shoving the wire with it but I didnāt think it was so hot as to do that. It was weird almost like I hit a pocket of gas
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I have one wire left open on my bms the first bms I took off it was running super hot. Now i have the Daly and its all running hot I took the Daly bms off the battery itself is emitting no heat. Iām about to post a video
I think thatās what it was man. I just see what I did at the pack. Doesnāt start where the wires at it starts with the open one I fucked that one off.
Sometimes i feel like im getting worse at this. But this battery started out looking amazing until I ran into a problem and started getting irritated now it will pretty much supply power
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looks like that first pic was enough. and yeah confirming what you found.
you put your black balance lead the same potential as the other balance lead. (other side of the big series wire) but it needed to go on the positive side of that pgroup.
this is suggesting that you also confused yourself about the polarity of the pack. which I think you mention in the video.
so looks like you figured those two things out correctly.
Iām no expert. but I will add there are several things that look suboptimal about this pack.
The PVC wrappers on the cells should be considered āno protectionā. Consider the whole can of the cell ānegative sideā as anything that abrades through the pvc wrapper will connect to the negative of that cell.
so within a pgroup itās ok to have them side by side glued together. between pgroups you should have something more abrasive resistant. such as āFish-paperā. This pack appears to be putting each pgroup pair up against the nextā¦ with nothing but pvc wrapper and hot glue in between. this has the potential to short. and fire.
Assuming that was solved. the next potential issue is balance lead routing. you need it to avoid being against the side of the exposed cells (consider the PVC wrapper exposed cell) without fish paper in between for abrasion resistance. You also want to avoid them crossing other wires as much as possible or add fishpaper between the crossing if they do.
last the pgroups nickle tabs are protected by fishpaper (good), but some of them look dangerously close to the edge of that fishpaper. if the edge of the fishpaper were to abrade or get smushed out of the wayā¦ the tab could hit the side of the cell. which on the positive side would be positive to negative short.
I would not feel safe with those problems unaddressed in a vibration heavy environment like an esk8.
Thatās my thoughts. hope they help. and i know critques suck. 
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Of course! Silly me, after all my time riding with @MichaelWA I shouldāve learned by now that silicone is the solution to everything in esk8 
I forgot to get decent pictures before applying silicone but I was able to align the wires a bit better, theyāre now shaped a bit like a ribbon thatās been twisted and covered in silicone. Like this
They come out pretty straight and even now.
Iāll have to reevaluate just how insulated the BMS is after I reassemble and disassemble the foam another 8 times but Iām not planning to use anything faster than a 10a charger on this pack, the BMS is rated to 20a and Iām using 18awg for the charge port. So I think I should be okay unless Iām really packing the BMS in there.
Does the LLT BMS itself have a temp sensor inside the BMS?
There are 2 temp probes coming out of the BMS to be placed on the battery wherever youāre worried about heat being generated, if I want to monitor my BMS temp, do I need to place one of those probes on the BMS?
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