Hey guys.
Since I’ll be travelling soon, I’d like to take my board on a few airline trips.
I have some 25R batteries I am considering fashioning into a 10S1P configuration to hit 90watt hours for airline travel.
Since I don’t want to rip a 10S BMS out of my secondary pack, do you guys think it would be fine for a couple weeks to run without a BMS on such a simple pack with appropriate discharge cutoffs on the VESCs?
No, you need a bms. Do it right, do it once. Your charger will keep charging an overfilled series group. Then one series will be high while the other is low and this all leads to failure or a fire.
Can you travel with a spot welded 18650 pack these days? Or any diy battery pack that is tampered with?
I for one would hate sitting on a plane with someone’s homemade battery pack right next me 
For real… I trust my work but others make me nervous.
As long as it’s under the watt hour limit and has some mechanism to prevent fires (BMS) they should be fine. Especially if it actually looks reasonably professional - no duct tape!
Well fuck me. I’m never flying again 
Terrorist don’t need to smugle bombs on board anymore. Just make yourself a few 100w battery packs and heatshrink those bad boys up and let the firework begin
I’ve felt turbulance so hard that passengers flew up in the roof and broke bones… Things can go south even tho you know what you are doing… How about different pressure in cabin? Would that affect a battery cell?
Edit. Ouh sry getting OT. Never mind me
It will look professional and be as safe as I can possibly make it. Rounded nickel, fish papered terminals, isolated connections, fishpaper around whole thing and between P groups, and under 90wh.
I’ll go ahead and strip the BMS from my other pack, that seems to be the clear consensus.
that sounds good. Usually the limit is 100 or 160Wh so <90 should be fine. Worst case you can ship it to your destination beforehand - same restrictions as flying but no TSA to fight.
rounded nickel is not necessary and in fact, it looks janky to someone who is not familiar with battery packs…
You can run a battery without a BMS if you set it up for a balance charger. There are a few 10s balance chargers out there, but 6s chargers are much cheaper, so you’d have to break out the balance connectors into 2 5s packs.
All this might be too much trouble if you have a BMS laying around or can wait for a delivery. Personally, I like using an external balance charger and have no on board BMS’s on my boards. So yes, it is possible and may even make sense depending on your situation.
Ive considered this idea a few times. The key for me is making sure that the charger and BMS are in the same package. For example - I am using a generic AC to DC converter (Similar to this) So if I wanted to make this a neat package id need to wire in the BMS to the power rails then wrap it all up in a proper casement.
there are a few DIY BMS’s out there and Marco Reps or Great Scott did a video on one that id be interested in trying out with this idea. But alas all of my time is expended assembling a number of cheapFOCers atm.
Meaning up for sale soon or just for yourself?
For myself and a few buddies that are more inept with a soldering iron than id care to admit.
Okay, after some research, I will not be flying with a self made pack. Airlines require batteries to comply with all UN tests part III subsection 38.3, like smashing them, forced discharge and overcharge, thermal tests, short circuit tests…
I know I can make a safe pack with BMS for charge/discharge, fasioned in a way that would probably pass these tests, but still, DIY is in no way certified so I’ll just leave my board at home and maybe take an analog. 
If you were going to make your own, why not just order some 5s hobby packs and be done with it?
Because I have two nights to plan, and am working on cheap with supplies I already have. If the cost of two ubers + skateboard battery beats getting a rental car for four days, I’d like to do that. If it were a longer stay, a couple 5s batteries would be perfect, and still beat the rental car.
I’m really wishy-washing here. Some airlines I’m taking don’t talk about the UN regulations at all… Spirit seems to be the most strict. If I can save a shipment via some carrier and take it with me I might do that. Regardless, I’m building the battery wether I take it or not.
With that said, with what you guys see above so far would you guys feel safe compared to a hoverboard battery as it is so far? Recharging welder now.
Also, thanks to @J0ker for the Kapton tape, pinchy timing, better planning next time.
Where do you get your fishpaper, everything i find is garbage.
Unfortunately I cannot say. It could have been amazon, ebay or aliexpress… For some reason none of those are showing any orders with fish paper, even though I know I ordered it within the last year from one of those three sites. I want to say it was from Aliexpress… adhesive backed barley paper is another name for adhesive backed fish paper.
