Lithium Ion batteries (rechargeable) and safety

Reddit to the Rescue?

Lol, just used that title for the alliteration. Here's a thread with some thoughts on what I'm looking at doing:

• Anyone here ever looked into using Lifepo4 cells/battery packs for their ebikes?

Final post: "If I understand right although they're safer and last longer they are also heavier, larger and carry lower capacity which makes them unsuitable."

And post just before it (aka the Penultimate Post): "If you're adept enough to build your own battery pack it's energy better spent on learning how to properly use and maintain a Li-ion pack than swimming up stream with a battery chemistry that doesn't really fit the requirements."

Maybe I should look into that as well.

I see there's an r/ebikes (where the above thread is located). Could come in quite handy.

Found in the r/ebikes Wiki:

"Lithium Iron Phosphate is currently the most common lithium battery used in Ebike applications. It is considered the most stable lithium battery type available today (low risk of fire) and has a reasonably high life expectancy of over 1000 charges.

"For a complete write up on LiFePO4 care and trouble shooting read our story here. LiFePO4 cells nominal voltage is generally from 3.0-to 3.2 volts, and generally, lifepo4 is a heavier and less power dense than available LiPo batteries and is not capable of as high of amperage discharge.

"LiFePO4 is currently widely available for purchase as e-bike packs complete with BMS on ebay and other online merchants. Mostly it is sold by small companies. Also, most of the commercially available e-bikes powered by lithium batteries are using the LiFePO4 chemistry."
Source​

So now it seems like those commenters on the Reddit didn't know what they were talking about (no, that doesn't happen, does it? Gasp!). And I'm back to thinking LiFePO4 is the way to go. Why would I mind some more weight, since it's a freakin' eBike?! I don't plan on pedaling it much.

... And it hit me—if I'm riding an eBike, rather than a regular pedal bike like I used to, I won't be able to ride on the sidewalks anymore, or toward oncoming traffic, so I can see what's about to hit me. Those are two things I always did, and I don't think I'd care to ride if I can't do them anymore. As for riding on the sidewalk, I would only do it when the sidewalk was clear—if anyone was walking there or waiting for a bus or something I'd always get down in the street and go around them.

I only got stopped once by police, in 2.5 decades of riding, and that was a rookie officer. I think they all recognized me and knew I was a considerate rider despite the fact that I technically broke the laws. I suspect most of them understood that it isn't safe to ride with traffic coming from behind you, so if somebody is too close you won't even see them until they hit you, and that there's no reason to not use the sidewalks as long as nobody is walking there.

Plus I can't help but think that an eBike is going to be much stronger theftbait than a regular bike. I never got one stolen, though a friend did. She went into her apartment and left her bike sitting in front of the building for like 5 minutes, unlocked, and when she got back out it was gone. I never parked mine anywhere downtown (which is where she lived) without chaining it to something, and I always made sure the chain went through the frame and both wheels, because I had the quick-release levers—the wheels come off really easily, and if I wasn't careful I'd get back to find just the front wheel chained up, or just the bike frame.

But yeah, I don't think I'd enjoy riding if I had to always ride on the shoulder with my back to oncoming traffic and could never use the sidewalk. And I'm pretty sure with an eBike they'd make me do those things.

It turns out the battery charger I already had will also charge LFP batteries (LiFePo4). Wish I had thought to check that before ordering the new charger. You just have to hold down the button for 6 seconds to switch it from Li-Ion to LiFePo4. And then you can tap the button once to switch it from charging at 500 amps to 1,000, to get them charged much faster. That's apprently totally safe with LFP batteries. I charged a couple recently and had no issues.

I really like the battery charger I'm using (the original one)—it's this model:

• 18650 Battery Charger, Keenstone Smart Universal Charger

They specifically call it an 18650 battery charger, but really it will hold many different sizes and types. I like that it automatically detects what voltage etc it needs to use, and whether the battery needs a trickle charge for a while, and it just does what if it needs to. It's a smart charger. Plus all the comments I saw for it are highly positive. I like it a lot better than the one I just got when I bought the LFP batteries. That one isn't a smart charger, you need to set everything manually, and after charging my batteries I discovered there's a tiny little switch on one end of it you need to set for how fast it will charge (500 or 1,000 amps, or Ma's or whatever it is, I forget the terminology). The instructions are printed so small I had to get out a magnifying glass and put on reading glasses to be able to just barely read it, and then of course the instructions were written in Chinese or something and poorly translated, so you have to wade through a lot of gibberish and try to figure out what it really means. Of course that part's also true for the Keenstone charger, but what can ya do? Just about all this stuff is coming from Asia these days.

Safety testing for LiFePo4 batteries

Looks like the LFP batteries (LiFePo4) aren't immune to catching fire:

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But at least it isn't like the massive death-jets of intense fire that shoot out for 15 feet in several directions you get from Li-Ion and most other rechargables, plus, at least in this test, it isn't caused by overheating but only by puncture. That would be analogous to gasoline cars catching fire because of an accident, which is what usually causes that.

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Encouraging results. Unfortunatley the only batteries I've been able to replace with LiFePo4 are for my flashlights—the rest are all unidentified Li-Ion technology, most of which I don't think are replaceable. I have two laptops, a couple of lanterns, an electric drill, a string trimmer, and a (useless, weak-ass) leaf blower, all rechargeable. One of the lanterns might allow me to remove and replace the batteries, the rest definitely don't. Hopefully, since this testing has been done and the results are clear, industries will start to move toward the safer alternatives.