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Comment by germinalphrase | Hacker News Reader

The problem is probably the battery. They worry about a battery fire int be luggage compartment.

Yes, and two possibilities came to mind for doing the battery differently.

A TSA-compatible 99 Wh power brick or two, suitable for checked and carry on, providing limited duration and assistance, but being at hand.

And a COTS "portable power station"[1], which can be ground shipped to meet you at your destination, from home, or from a store.

The ideas are to optimize the bike for shipping by removing any trace of the battery from it. And to optimize the battery for shipping and availability by going generic.

EDIT: Another comment[2] observes the battery in the post is available from Home Depot, so that might suffice for COTS generic availability. So an airline story might reduce to: leave the battery at home; attach the conversion with velcro instead of zip ties (or bring snips and a bag of ties); unbolt and remove the conversion before check in, and bag it separately from the bike; get a new battery at the destination, by visiting or shipping from Home Depot; and put the conversion back together.

[1] eg https://www.amazon.com/s?k=portable+power+station [2] https://news.ycombinator.com/item?id=28270285

Good luck getting usable range out of two 99Wh batteries with such an inefficient drivetrain.

Ah, interesting, the article doesn't seem to mention range.

This comment[1] reports the article battery as 160 watt hours, so 2x 99 Wh might be an upgrade.

One use case I pictured was last leg after airport arrival when traveling minimalist and budget. As a transportation alternative/supplement to mitigate last-miles time/$/hassle cost.

[1] https://news.ycombinator.com/item?id=28273273

https://ebikes.ca/product-info/grin-products/ligo-batteries.... 98Wh each, can be hooked up in series (already 10s = 36V nominal, max is 2 of them for 72V nominal) and parallel.

"While most airlines do not have a firmly defined maximum number of batteries under 100 Wh that can be brought aboard, we'd suggest travelling with no more than 4-5 LiGo's per person in order to avoid extra scrutiny. We have had customers travel by air with as many as 12 LiGo modules on them, but we wouldn't recommend that as a matter of course."

People traveling with folding bikes and LiGos: https://www.bikefriday.com/folding-bikes/the-only-electric-b...

Exactly, get a removable battery and bring that in your carry-on and it should be fine.

Are you joking? Lipo batteries in a carry on?

If you read the article, it specifies lithium-ion batteries, which just about everyone brings inside the pressurized cabin.

So no, I am not joking.

I just know that most ebike batteries only ship by ground and even that isn't easy. See this for example: https://entrepreneur.indiegogo.com/education/article/how-to-...

Sorry for the tone, I honestly thought you might be joking.

Yeah, all lithium batteries ship via ground, but that's generally because cargo planes are basically like shipping things in the cargo section of passenger airplanes, which generally isn't advisable.

That's because shipping is more restrictive than carry-on and because of the capacity. People carry all kinds of lithium batteries onto planes.

There is a big difference between cellphone / laptop batteries and some random enormous 72V battery you might buy from AliExpress. I have used those big batteries and the word I would use is “scary.”

My battery pack could have been easily mistaken for a bomb. It was duct taped together, wires coming out of it, heavy and blinking lights on a home made exposed circuit board for the battery management system.

I tried a 72 volt setup for about a week. Too fast lol.

I’ve seen these. All fun and games until they’re forgotten in the basement for a while. Big puffy batteries just waiting for an excuse!

I went through an airport with a home-made LiPo in my backpack. Fortunately one of the TSA recognized it was just a battery but it was a really scary few minutes. Lots of very silent stares

The battery in the article is 160 watt hours, the kind that slaps into yard equipment. You can get permission to carry that, or use two 80Wh drill batteries instead.

Yes absolutely. Those are in the minority of the home-made ebikes that I’ve seen, though - mainly due to range and power output. People love a bit of power, and they think any battery is just a battery.

I’ve seen a couple of “spicy pillows” smoke out, never a full thermal runaway fire - thank god

People bring small batteries in the cabin. It also makes a difference if they're integrated into a product or not. E.g. you're allowed to being a laptop with a medium sized battery on board, but not a standalone lipo battery even if it is smaller than the laptop battery.

The only rule that differentiates between integrated and spare batteries is that you can't check spare lithium ion batteries. For carry-ons, the rules are exactly the same for both.

https://www.faa.gov/hazmat/packsafe/resources/media/Airline_...

The rule is under 100Wh per battery, usually without a clear limit as to how many batteries.

https://www.tsa.gov/travel/security-screening/whatcanibring/...

Reply on news.ycombinator.com