Yep. But we don’t usually because it’s a pain and takes extra space/weight/engineering to do it.
Buy round li-ion, and they’re pre-compressed.
I think those are like the turds that Evolve use, but I’m not 100% sure. I bet @longhairedboy knows. These seem to be the exact ones they use in Carbon GT. Stay as far away from these things as you possibly can. But if you wanted a pile of used ones to play with, I bet some are available
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Maybe. What if the round shape allows a machine to roll that sucker up super-tight with thin layers, making it more efficient? I agree with you, but there are known-unknowns and probably unknown-unknowns here
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Exactly. All I’m saying is, there’s gotta be a reason so many EVs (And other industries) use cylindrical cells. If they were a shitty idea, everyone would be using pouch lipos for everything.
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Pouch lipos are in cell phones, tablets and etc. As far as large scale industrial manufacturing goes, companies like the one that makes iPhone batteries have the machines capable of consistent production. This guy, whom I believe is with revoelectric, has some interesting things to say about it: https://www.rcgroups.com/forums/showpost.php?p=29238904&postcount=1774
This is linked in the main article I linked a few posts up. Tldr, it seems that industry is tooled for liion and small capacity lipo manufacturing, but not really for large capacity lipo manufacturing. And as the graphene lipos are fairly new among lipos, commercial adoption may be limited to hobby batteries for a while.
My thoughts anyway, but what do I know. Pretty much thinking “out loud”
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But lipos have their cables which take up space as well Its not like you would put something where the empty space of li ions is
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The shape of that box, I don’t think you can get interesting lipos in there.
Plus, the diyelectric esc most likely has voltage cutoffs for lithium ion, not lipo.
Plus, if you do the same thing to the lipos that you did to the 10s2p pack, 
The cheapest decent lipos are usually the 30c or 40c hobbyking, zippy or turnigy. Usually 3s or 4s for the shape (makes 10s difficult).
You can hit 10s with 2s or 5s lipos (usually), both of which will be difficult to fit I think.
yeah… it costs to be careless, especually if youre going to dump the voltage every ride
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How did you over discharge? I think that esc has lvc, and I think I see a bms?
Yo, I have the exact same enclosure with 2 4S 4500Mah Zippy Lipo, looking for an upgrade actually because 4.5Ah with 8S is pretty poor, I have an actual 12Km range and a 30km/h top speed. Mounting a bms need some knowledges, I could do it again if I change for 10S or 12S but i’ll Need some time so it’ll be better to have one bms included battery !
However this is how it look like with my 2 4S +Bms
Mounting a Sanyo 10S 8.1Ah looks like to be an interesting idea, 27Km range estimated with a higher top speed (10S…) but the max amp is way lower than with my 45C pack from where I can suck 50A easily, there i’ll Need to go for only 30A and I don’t really know what will happen.
However it could be a noice choice because Bms is integrated and they are made to fit our ownboard/meepo enclosure !
Keep me updated tho !
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On theory you can also do hexagonal packing:
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I think the majority of battery failure we have been seeing lately is improper construction or something wearing down. The safety of the battery at that point really isn’t the issue.
Both batteries have their pros and cons. I think as far as safety goes, its going to be a personal preference. I feel safer with a well built Lion battery over lipo. I’m personally had lipos from cars and quad puff up and catch fire within a few minutes of pushing them too hard.
But some people have the same horror story with lion batteries! So that’s why I say its going to opinion and application that will help with the decision!
Yea I think the danger w ion is largely the battery pack construction: people are spot welding for the first time then throwing it in one of the most abusive environments. Ion battery packs often have sharp nickel strip n the thinnest insulationand the possitive terminal is like a mm from the negative under that thin wrap. It seems the chemistry isn’t as the rest of the variables in my mind and either could go either way
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100% agree with you.
I’m working on my first battery pack ever and I’m keeping an eye out for any spot that could be a potential downfall. I’m rounding out all corners, insulating with fish tape, using kapton tape, doing cell level fusing.
I feel more confident with my work so far than a store bought pack from HK. (Unless its a graphene pack, those things are amazing)
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I use VESC. Bypassed the BMS for charge only. One day after I finished charging I turned the board on to check battery % with Xmactic, then forgot to turn it off. The next day…there was no next day… :’(
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Damn it looks so cramped! How do you connect the balance wires to the BMS? With this setup you just need to plug the 42v charger to the BMS right?
This is the point I was talking about. In tight area like mobile devices they can’t use a cylindrical shape, therefore square-shaped battery can get the most out of energy/volume ratio. Laptops used to carry the big bulky removable 18650 pack, now with laptop being thinner and lighter, most have square lipo/lion pouch in them. I’m wondering if there’s any variant of lion exists that has metal housing like 18650 but rather in square shape. Edit: oh wait I think I found this, not sure if it’s credible
The difference between the two and the nomenclature and the plastic ingredient as a red herring, it’s confusing, but does allow use of some of the longer words n expressions which haven’t been over trodden. If u find out what is what I’d like to know. Or skip to the end and just buy a lipo making machine off alibaba. Lipo machine group buy and we go for graphene quality.
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lol. I would if I could afford that. Then this thread wouldn’t exist in the first place xD.
Btw, I’m looking at those HK lipos. Is yours still going well for you? From what I read the zippy line up is the worst of all.
TURNIGY® Batteries explained Zippy: Great value for money. Average Cycle Life* (100+) and minimal voltage sag under load. TURNIGY Standard: Excellent value, Longer Cycle life* (160+) and very low voltage sag under load. TUNIGY nano-tech: Unbeatable performance, Longest Cycle Life* (250+) and almost 0 voltage sag under load. *Cycle Life results from discharging at full C rate to 3v. End of life when battery has 80% capacity. Radio Control Planes, Drones, Cars, FPV, Quadcopters and more - Hobbyking