Modular 12S8P Air Travel Pack Build

I’ve ordered everything, plan to build this in the coming weeks to finally enable FLYING to interesting skate spots. This is the culmination of 5+ years of reading, re-reading the FAA and IATA rules, reading about others’ experience, and trying/failing several other ways to make a legal single pack (tiny LTO + quick charge, monster NiMH.)

Batteries 99Wh or less are a GO, do not require airline approval. (100-160Wh pack DO require airline approval, invoke a whole new set of limitation.) Devices that serve primarily as chargers/powerbanks/power supplies for something else are considered spare batteries, and the only limits I’ve found are FIFTEEN and TWENTY on the quantity of spares, depending on where you read.

So, I’m building 12 individual 1S8P 18650 packs using modular polycarbonate boxes + cheapie bidirectional USB-C boost/buck boards just to give them some function when not part of the larger pack. I already have at least 100 30Q cells, which will yield 24Ah, 1036Wh. 3300-3450mah cells delivering at least 10A continuous would be a better choice, yield closer to 1.2kWh, but I’ll use what I have here. 8P of 15A 30Q cells should deliver plenty of current for any board… 120A on paper. (I’ve never drawn more than 70A from a 12S pack.)

There’s nothing fancy going on here, just a pre-made box that happens to fit nicely x12 into the tool bags I’ve used for top-mount packs for years. I plan to stack them 4 across the deck, 3 along the deck, should occupy 101H x 255L x 196W w/o the BMS. I plan to use all 8 bus strips inside each, may get fancy & cut/punch copper sheet to replace the included bus strips if they prove weak. Each box will be finished with 2x 5.5mm sockets on the Neg side, each fed by 2x 16GA wires (35A each, 70A per bullet) and thick M3 ring terminals, and 2x 5.5mm bullets on the Pos side to enable easy series connection. (I’ll use sockets on the last Positive pack for main output to match the bullets on my mountainboard harness.) I’m using a JBD BMS to manage the whole pack, will terminate the balance harness with 2mm bullets for easy connection to each sub-pack. Again, the balance connection will be made with a 3mm ring terminal on a short pigtail w/ the matching 2mm socket.

When I fly, I’ll have a dozen ~1lb 101x49x85mm boxes to stash in my carry-on and on my person, each of which are transparent, showing nothing but labeled legit cells, nothing loose inside, protected I/O via USB Type-C, demonstrable function. Since they are 1S, all cells are aligned the same, no potential for internal shorts at the screws atop or on the bottom. I’m Kapton taping the charging PCB to prevent shorts too. All 5.5mm and 2mm bullets will be tucked inside the covers… no external wires.

To assemble the pack, I remove all the covers, (2 screws each,) flop all wires outside, connect the 2x parallel 5.5mm bullets between each sub-pack, connect the 13x 2mm bullets for balancing, replace the covers, cram it into the bag, go skate.

There IS a way to connect these using the included bus strips, but I want quick/easy assembly/disassembly, will add the bullets to enable. This whole thing could be done w/o any bullets if you’re willing to fool around with a nut driver to assemble… I’d do so for a non-flying version, but for that, why bother with modular at all?

Here’s what started this madness:


@poastoast has lots of experience in this area


I got pretty creative searching, can’t find a thread of his related to a travel pack. You know about when, in relation to what he posted? (I hate to bug him if the info is searchable… I’m just having trouble finding it.)

Maybe it’s been discussed elsewhere but Why not use power tool batteries?

They are usually pretty ruggedized, have readily available adapters chargers etc.

Maybe slightly less compact but have the benefit of not looking like a bomb.

I’ve been toying with the idea for a while now…

Fucking hoverboards and Samsung for shedding light on the issue…

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I dont think he made a thread on it.
Iirc he made a bunch of 6s1p p42a modules in slick 3dp cases.
Then made a wild harness to connect them.
Pretty sure he uses a balance charger to charge em.

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Great! So I’m not nuts. This is essentially the same way segmented packs are made for Flux and Lacroix under-mount enclosures to allow the pack to flex. I feel like a cop-out buying these instead of 3D printing something similar, but who’s got the TIME? I wanna fly around the country/world to eskate!

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Hoyt St Battery Packs (

If you don’t want to build your own, this is an option.

Also, buying a revel kit and several replacement batteries would work for travel safe option.

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imm too lazy to document

i’’ve made roughly 50 packs so far with about another 20 comin up, cells arriving today

one thing to note about TSA

don’t forget that even if the rules say ok, the TSA agent still has final say, so if they say no and take your packs, you can’t pout about it much.

i know you know but if anyone else is lookin for the rules

TSA has no official limit on packs that go up to including 100Wh, some airlines do impose a quantity limit
101 to <160 Wh, you’re allowed up to 2 spare , meaning separated from the device

in practice,
always expect to be pulled aside for further bag screening, and make your packs labeled and everything.
airlines aren’t there to babysit and enforce their quantity limits or check if they gave you approval, but TSA might grab a gate agent if they feel the need to

friendly reminder that the TSA is not everywhere, different countries will have different rules


do you have the build materials


if you open em ip, it’s prettttty cheaply made, and the nickel tabs inside won’t be able to ha dle the constant load that esk8 could impose on them, not to mention the connector


Not to mention how much space they waste and how much stuff you need to use them


bot not to mention the cells wouldn’t handle the current either

Just a warning: not all airport employees or TSA employees will strictly follow the rules for what is and isn’t allowed. Meaning, even if it is within all the rules to bring on a plane there is a chance an employee will say it isn’t allowed.

Had that problem with a pair of tiny shears with non-removable blades. The entire length was well within the allowed lengths for scissors and the blade length was way under the maximum allowed length for scissors. (normally they only measure scissor length from the pivot point to the tip. my pivot point was at the end)

I’m not sure how you could be sure to never have any problems aside from keeping a printed version of the rules the battery will fall under.

have you ever had them question the labeling on the packs you have? it looks super clean to me but I feel like someone who knows nothing about batteries might try and say the label is incorrect or some other dumb shit

never had problems,

It goes both ways too, I remember back in the day Casey Neistat would take his boosted board on planes all the time and I can only remember it getting confiscated once. I think being respectful and explaining it to them if they ask would be your best bet, most of them don’t know nearly as much about batteries as anyone that is capable of building a pack.

I do wonder if they will buy the whole '“spares” thing if they really start questioning you. Something like a power tool battery pack is obviously a self contained spare battery, bms and all included, and a standalone packaged thing these are just a cells shrink wrapper together with come cables that the TSA definitely doesnt know the purpose of coming out.

Also, do you take the packs out of the enclosure when traveling or even unplug them to clearly separate them?

packs are separated from the board

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“technically” the most safe way is to put them in individual ziplocs. When I flew with my lipos I put them in pairs of two in ziplocs and they didn’t even blink an eye

True but it has the data listed on it, they don’t have a good reason to NOT believe it. In any case, it’s not like you’re going to assemble it on the plane lol

that’s good to hear - I’m planning on flying to PDX with my modular battery lol

i meant no issues with my labels

i’ve been pulled about every time except once or rwice
, one airport had to oull a “materials expert”
that said, i’ve also never had my batteries taken
I have TSA precheck and tend to fly early morning, so i can’t say if regular security will be good or not

i’ve been to


so far
on a similar note, i’ve brought multiple small lipos through these airports, in addition to the recently stated airports

DUB (Ireland)
AKL (New Zealand)
ZQN (New Zealand)


Oh haha, ok I see