Lithium batteries or whatever

Ok so my buddy mike asked me to write something about lithium battery technology for his blog and im like sure why not. been messing with these things since 2019 when i bought this cheap chinese power bank that literally caught fire in my backpack (long story, ill get to that)

lithium batteries... theyre basically just rocks that store electricity? lol ok not really but kind of. the actual chemistry is lithium ions moving around inside the battery between two sides - the anode and cathode (i always forget which is which honestly).

when you charge it the ions go one way, when you use it they go back. its like a tiny subway system for atoms or something. my friend sarah who has a phd in chemistry tried explaining it to me once at a bar and i was too drunk to remember most of it but thats the gist.

the thing thats actually important - and this took me YEARS to figure out - is that not all lithium batteries are the same. theres regular lithium ion (like in your iphone), then theres LiFePO4 which is lithium iron phosphate, and a bunch of other variants with cobalt or manganese or whatever.

Lithium batteries

so yeah, 2019. i bought this 20000mAh power bank off aliexpress for like $15. seemed like a good deal right?? wrong.

i was on a road trip through arizona (terrible decision btw, its SO hot there in july) and had the power bank in my backpack in the backseat. came back to the car after hiking and there was SMOKE coming from my bag. the power bank had swelled up like a balloon and was making this hissing sound.

scared the shit out of me. threw the whole backpack out of the car and waited for it to... i dont know, explode? it didnt explode but it definitely melted some of my stuff. lost a good pair of sunglasses that day. RIP.

anyway thats when i started actually researching this stuff instead of just buying whatever was cheapest on amazon.

the different types of lithium batteries have different risks. like that power bank i had? probably had regular lithium cobalt oxide cells. those are GREAT for energy density - you get a lot of power in a small space - but theyre also the ones that can go thermal runaway.

thermal runaway is when the battery starts heating up and it cant stop itself. gets hotter and hotter until it either catches fire or explodes or both. fun times.

lithium iron phosphate (LiFePO4) batteries are way more stable. the chemistry is just... less reactive? something about the iron phosphate being more stable at high temperatures. i dont remember the exact reason but ive never heard of one catching fire.

downside is theyre bigger and heavier for the same capacity. also lower voltage - like 3.2V per cell instead of 3.7V. doesnt sound like much but it adds up.

temperature is HUGE. like massive. i live in minnesota now and in winter my electric bike battery loses like 30% of its range when its below freezing. not because the capacity is lower (well it kind of is) but because the chemistry just slows down when its cold.

in summer its the opposite problem. leave a battery in your car when its 95 degrees out? youre degrading it. maybe not a lot, but it adds up over time.

also - and this is something that pisses me off about manufacturers - the "cycle life" they advertise is complete BS. they test these batteries in perfect conditions at like 20-25 degrees celsius, charging and discharging at specific rates, never going below 20% or above 80%.

in real life? nobody uses batteries like that. you charge to 100%, use it till it dies, maybe leave it sitting dead for a week before charging again. that kills batteries way faster than the "ideal" usage pattern.

i had a Jackery power station that was rated for 500 cycles. lasted me maybe 300 before it was noticeably worse. still works but definitely not what i paid for.

EVs - obviously. teslas, rivians, all the new electric cars. Tesla actually switched a bunch of their standard range cars to LiFePO4 batteries because theyre cheaper and last longer. makes sense for a car you might keep 10+ years.

the downside is slightly less range but honestly who cares. most people dont drive 300+ miles in a day anyway.

solar stuff - this is where i got into it originally. wanted to build an off-grid setup for my cabin (dont have the cabin yet but im planning). lithium batteries are way better than the old lead-acid batteries everyone used to use.

lead acid batteries suck. theyre heavy as hell, you have to maintain them, they dont last long, and they dont like being discharged too much. lithium you can basically discharge all the way (well, 80-90%) and itll be fine.

portable power - camping gear, that kind of thing. i have a Bluetti AC200P that i take camping sometimes. its heavy but you can run a fridge off it for like 2 days. pretty cool.

also those electric coolers are getting really popular. my cousin has one for his truck and he loves it. runs off a lithium battery, keeps stuff cold for days.

Lithium batteries

ok so lithium batteries are expensive. like, really expensive. that Bluetti i mentioned was $1600. for a BATTERY.

but heres the thing - and this took me a while to accept - theyre actually worth it if you use them enough.

that Jackery i had that only lasted 300 cycles? i was using it almost every day for my laptop when we had power outages (our power grid sucks here). so 300 cycles was like a year. if i had bought a lead acid battery setup it would have been way more of a pain and probably wouldnt have lasted much longer.

plus no maintenance. with lead acid you gotta check the water levels, keep them charged, all this annoying stuff. lithium? just use it.

still hurts to spend that much money upfront though. not gonna lie.

remember my power bank fire? yeah dont let that happen to you.

things that will F up your lithium battery:

extreme heat (above like 140F)

extreme cold (below 0F especially when charging)

physical damage (dont drop them)

wrong charger (use the one it came with)

leaving it dead for months

if your battery swells up or gets puffy STOP USING IT IMMEDIATELY. dont try to press it back down or "fix" it. that battery is done. get rid of it safely.

also dont charge batteries overnight unattended in your house. i know everyone does this with their phone but with bigger batteries like power tools or power stations... maybe dont?

i charge mine in the garage now after the backpack incident. call me paranoid but id rather not burn my house down.

everyones talking about solid state batteries. supposed to be safer, higher capacity, charge faster, all that good stuff.

been "5 years away" for like 10 years now though lol.

what IS happening is more companies using LiFePO4 for stuff where the extra weight doesnt matter. home backup systems, RVs, boats, that kind of thing. makes sense - safer and lasts longer.

prices keep coming down too which is nice. that Bluetti i bought in 2021 is like $300 cheaper now. kinda annoying but whatever.

Lithium batteries

lithium battery technology is pretty cool once you get past all the marketing BS and actually understand whats going on.

main takeaways:

LiFePO4 = safer but heavier/bigger

regular lithium ion = smaller but riskier

temperature really matters

cycle life ratings are optimistic at best

buy quality if you can afford it

dont leave batteries in hot cars seriously

also maybe dont buy sketchy power banks off aliexpress. learned that one the hard way.

thats about it. mike if youre reading this you owe me a beer for writing this lol

oh and one more thing - if anyone knows a good electrician in the minneapolis area who can help me wire up solar panels hit me up. the quotes ive been getting are insane.

ok done now. gonna go charge my power tools before i forget again.