SpiderBatterySystems Flat Pack Review

Lishen LR2170LA 12s4p Flatpack built by @SBS

Purchase Experience:

Payment, and communication were both very clear and straightforward. I was able to discuss custom options and prices at length prior to purchasing and never felt pressured. He even suggested some options I hadn’t thought about. He’s obviously very experienced in DIY esk8 and the care shows in little details like an XT30 inline to make mounting the charge port easier or the choice of charge port he includes. The pack was ready within 4 days of placing the order and arrived 3 days after that, as per Canada Post's usual, tracked and with a signature required upon delivery.

Included in the box:

  • 1x Information Sheet (warranty, liability, warnings, disclaimer)

  • 1x Velcro :registered: strip

  • 1x Battery Pack

  • 1x 20A LLT smart BMS (Connected to pack)

  • 1x BMS Bluetooth module+cable (connected to BMS)

  • 1x Weipu SF20 2p charge port (nut type) connected to XT30 to the BMS with XT60-M on the cable side


please watch this on mute my roommates were making strange noises.





Final Opinion:

Tested Voltage upon unpacking: 43.4V
Voltage Delta: 0.007V

This pack looks impeccably made. [Post-ride review below], everything looks primo. I especially like the charge port included and the fuse. The glue dabs over connections is also a nice touch. This thing really rips.


I have zero experience with that cell. what are they like? think it will stay balanced?


I have some experience with it, but not experience I would call “successful” by this forum’s standards.

in my limited experience, they put 30q to shame and make P42A look a tad overpriced.

as far as my experience with the cell goes, I’m skeptical. but I think @SBS has done some good work here and I feel like the pack should stay balanced as long as I don’t abuse it.


I know it has to be there because of other photos, but I just can’t find where the balance lead is connected here lmao

Rest of the pack looks solid, braid series connections still scare me, I haven’t figured out how y’all stop it from wicking up the entire length

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metal ruler while forcing it down, the @slizer18 method
although part of the Troy method is also zapping yourself by shorting across the entire pack, so use protection


I have those cells in my pack - they seem to be doing ok but I’m also not pushing them to their limit or anything


bonus points if the short welds the ruler to the pack


Edit: Purchase experience added

So I’ve now drained the pack a couple times and charged it up.

@SBS has the LLT set to stop charging at 4.1V/cell which I agree is the way a new pack should come, using conservative values to ensure pack longevity.

I was informed of the proper low voltage cutoffs to use as well. It’s important to get that information in DIY.

The pack has shown to be balanced over 3 full cycles so far. I’m hitting it with 140A max (70A per VESC) and it’s been performing exactly as expected, not even getting warm.

I’ve been using a 6A WATE charger.

From my experience I’d say if you live in Canada and need a pack, you need to consider @SBS


To prevent it traveling down the braid, you need a hot iron that doesn’t need to linger, and you don’t use flux. Just a rosin core solder. I think the braid is fine in a non-segmented enclosure but I don’t understand why he puts the braids so close together given he has all that tab space. 2 out of the 4 batteries in each p-group will have a lower resistance pathing based on my minimal understanding of resistance. I think it’s mostly irrelevant though.

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I have used braided copper in a ton of packs. It’s awesome for low profile situations. don’t use flux, it will betray you. Trick is to use a very hot iron to tin the copper braid on the very ends. You have to do it fast, almost just barely tapping the flux core solder onto the braid with the iron. Then you put a bead on the nickel, as wide as the copper. Then you lay the lightly tinned copper on top of the bead, hold it in place with a wide flathead screwdriver to sink some of the heat off the nickel and keep your hands from burning (and it also seems to slow down the wicking) and put the iron on the bead and let it melt down and as soon as the copper drops into the wet bead you pull the iron off of it. It’s all about time, you don’t give it time to wick.

at least that’s how I do it.


As someone who doesn’t watch videos much, this is the fastest way to get me to watch a video. Not on mute.


What were they?

In order to maximize range I was told I could go as low as 2.5V/cell (30V) for my hard cutoff. I would use 34V as my soft cutoff.

Not worth it to go that low, better off with


3.2 soft

3 hard



There’s a whole thread for this, but I would never go that low.


Can confirm.

Had a 2.5km walk of shame because of it.


took me a minute too


Apparently medical clamp pliers are good for these, didn’t try them yet though.


Woooow! Im too embarrassed to admit how long I’ve been looking for it :joy:

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