I thought I might leave this diagram here, for reference to the different li-ion cells and what to expect from them…
It has been taken from Vapers community, so they have ohms / watt rating at the lower side, basically all is said at the two top descriptions - one is for capacity, the next one (lower) for discharge rate)
I self-paralyzed over battery considerations. Rather than say this is better than that, I’ll add a few more things to consider.
Depending on your use, all cells mentioned (and I’ll add A123) can make sense.
I’ll throw my 2c into the ring. I built a 12S5P lithium ion pack using Samsung 18650 30Q for about $300 it could be cheaper depending on 18650 cell and supplier. It’s a lot of cells, but it allowed me to configure and arrange them how I wanted and needed to make them fit. The pack has a capacity of 15Ah and 75A continuous discharge rate.
I also have 2 6S Multistar 16Ah batteries that are supposedly 10C max discharge. Realistically for our use, they’re about 5C, otherwise the voltage sag is too great. They were about $150 shipped. They are bulky batteries, I had to make a second enclosure just for when I run the Multistars because of their height. I could break them apart and a rebuild the packs, but that negates one of their supposed benefits of out of the box simplicity. They’re also heavy.
Overall the 18650 pack is lighter and will offer a longer cycle life and is more configurable, but at 2x the price. I went with that at first because I’m familiar with 18650 cells and didn’t know much about lipos.
The voltage sag on the 18650 pack is comparable to the Multistars but they don’t get quite as hot running at 75-80A drain. I’m not sure the Multistars could really handle 160A drain for very long I assume they would get very hot.
The reason I don’t see higher discharge rate as a plus is because people have been using the wrong 18650 cell all along for the sake of saving $20-30.
You are talking about using Lipos that can discharge at 200A continuous to discharge on average 20A and peak 100A. A 10S4P 30Q pack can do up to 60A continuous with very little sag and up to 120A burst.
I can buy these cells for a total of $180. Plus other materials maybe $50 A total of $230 and my time for a 10S4P that kills any LiPo pack In the $100 range maybe even in the $200 range just because you will not be needing the extra discharge ability and capacity on Lipos still sucks plus now youre carrying a massive brick under you.
My girlfriends build cost a total of $650 with a 10S4P Li-ion pack bms and charger, the pack is the one in the picture above.
-Lipos have less voltage sag. True but voltage sag is not an issue with the appropriate cells. For example here is the discharge curve for 25R cells which are the standard vs 30Q cells:
Top curve is 0.2A, second is 5A and third is 10A In a 4P pack, this would correspond to 0.8A (close enough to no load), 20A, and 40A. As you can see, the 30Q cell has less sag at 10A than the 25R does at 5A! In fact, after 50% capacity the 30Q has the same voltage sag at 15A than the 25R at 5A. That means that you see the same voltage sag when pulling 20A on a 10S4P 25R pack than you do pulling 60A on the 30Q pack! That is laughable.-Lipos have more power/dollar, True but again that is per dollar.
-Lipos are easier to install than building your own pack. Not if you use single cells… Using 18650 is the equivalent of using single cells. You can buy an assembled pack that is just as easy to use. Once again it comes down to cost being the difference. LiPos have a way bigger market than 18650 cells and therefore there are made in massive amounts in all kinds of sizes, while 18650 packs are not used widely so finding assembled packs is more costly.
-You always know the health by balance charging. How is this a pro for Lipos? I can also balance charge Liions/Lipos/Lifepos/nimh. Nothing to do with the battery chemistry itself.
It all comes down to the dollar signs… which is admittedly a large factor. Large enough that people do choose to go that route.
Performance wise, there is absolutely no reason to go there though. If you did then your system was designed with the wrong cell with all respect to you.
I think @radium nailed it with the one on one comparison. Performance wise, from what he described 30Q pack is the winner. Once you take cost into account, not too sure.
That’s my entire point, right there in that sentence. “You” can buy the cells and build the pack. Most people don’t have access to a spot welder or maybe aren’t willing to take the time to learn battery layouts or any of a number of reasons. To buy a 10s4p pack is $400 bucks. I can buy 2 4S 8000mah lipos for $100 plus $30 for a charger and get the same performance.
I’ve never ridden a board that used lion’s that didn’t slow down on a 15-20% grade, but with lipos I accelerate.
In what world is it as easy to use individual lion cells as lipo packs? I use 2 packs, meaning I solder 1 xt60 series adaptor. 2 mins work, tops. How fast can you build a lion pack?
I realize you can balance charge your lion packs. But do you? Do most people? I would say the overwhelming majority of lion users do not. Why buys a BMS if your going to balance charge?
I even built a 6s lipo pack with a BMS, I prefer to balance charge so I took it off. My b6 charged faster anyways.
Maybe all of my lion packs were badly designed, I doubt it, but maybe. Regardless, in 10 mins with lipos I am up and running, no worries. With lion packs, the majority of us are relying on the lion pack builder to make no mistakes, use the best cells, make it dummy proof, etc. I don’t have that worry with lipos.
If I get a bad cell in a lion pack I have to take or ship it to someone to get it fixed. At least 2 weeks down. If I have a bad lipo pack I replace it with another that took me 2 days to receive.
Once again, I’m not saying there is anything wrong with lion packs, I will even stipulate that they are moderately safer and "may’ not sag if built correctly. But nothing you’ve argued has proven that lipos have no place in the building and use of powered boards.
Mine doesn’t slow down on a 10-15% grade, and I get over 30 miles on a single charge. My total of $300 included a BMS and an appropriate charger. To get a comparable lipo config outside of the Multistar lineup would probably cost around $300 with a charger that could balance charge the batteries simultaneously.
I haven’t had my board working for too long, but in my limited testing I’ve never pulled more than 107A with 2 6355 motors. It was measured with that in line Turnigy power meter. How many amps are you pulling with Li Ion where you start to notice a slow down going up hills?
Another consideration is that I could probably add another 10-20 cells into my 18650 config if I put it into an enclosure the size of the one required for the Multistar batteries.
Either way, both are definitely useable, my only experience is with Multistar because it offered the most capacity for the right price. I imagine other lower capacity packs don’t get as hot.
If you buy a pack with built with 25Rs sure but they are crappy cells. If you buy a 10S4P made with 30Q cells, then no, the performance will not be the same. Power-wise they might be similar, endurance-wise, you’ll ride the 30Q pack twice as far. 8S 8Ah Lipo = 236Wh 10S4P Liion = 432Wh.
The point you make is that Lipos are cheap and I agree but performance wise compared to a 30Q pack they get left behind.
Were they all using 25R cells? If so, point is moot. The data above shows that cell sucks.
I meant if you used single cell LiPos. Sorry for the confusion. The rest of that paragraph should make more sense now. Lol
What do you think a BMS does exactly? A BMS is meant to balance cells when fully charged, protect from over voltage, protect from under voltage, protect from over current and protect from a short. All for $40.
I know your B6 doesn’t charge as fast as my $25 200W charger given that the Imax B6 mini is rated for 60W IF you got an authentic one. If not, you should know that you may be overcharging your batteries as the fakes tend to overcharge by up to 0.1V and I recommend you check it with a multimeter next time you charge.
The overwhelming majority use a BMS, so yes, they do balance their batteries on every charge. There are a few exceptions of course like White Pony and even then he knows how to take care of his cells so that they don’t go out of balance.
I meant it as in performance boards. Cheap builds under $600 that you can put together in less than a day, sure. They’re certainly better than ready to ride systems out there. But it doesn’t rival a properly built DIY system on the same budget. I spent $700 total plus roughly 3 weekends to get everything up and running on my gfs setup. It was my first build.
Sirry for the slow replies. I’m taking care of the pupp and shes needy.
No argument here, but 25R’s are what is most available, so that’s what most of us end up with. When comparing an 8s lipo pack with 236wh to a 10s3p with 270wh the difference is minimal and the C rating is much higher on the lipo. The cost is 1/3.
I dig that, but I actually see the voltage of each individual cell. With a lion pack you have to jump through lots of hoops to do that.
No argument, but it charges my lipos as fast as a 2a lion pack charger, that’s all I was trying to demonstrate. My accucel and by are legit, I’ve checked. I was kind of hoping it wasn’t so I could get the $50 gift card from Amazon 
.
Not arguing against that point either, just saying that I actually ‘see’ the voltage of each cell everytime I charge. That means I’ll see a problem that could potentially be unsafe much sooner than those that assume their BMS is doing its job.
That’s what I’m saying. Most people begin the DIY route because an @onloop or @longhairedboy powered board is mondo expensive. So telling people to NOT use lipos and that the only alternative is a $400 lion pack is going to turn a lot of people off to powered boards.
The way I see it, the more people involved, the more products, the products get cheaper, laws have to change because of pressure from skaters, etc. All that is good shit.
Go take of your dog, give her a scratch for me. Good dogs are one of the things, like skateboards, that make life bearable sometimes.
Here’s a question, and keep in mind I’m not asking you to build me a battery, just curious.
If I ordered and had shipped to you with a return shipping label ao you were out no money, only your time, the following…
30 30Q cells, 10 meters of nickel strip, a 10s3p BMS, cell heat shrink and pack heat shrink, 10m of 10g silicon wire, switch, charge port, volt meter and 2a charger what would you charge to build a 10s3p battery?
I’d do it for free. I have nickel wire and a bunch of 10AWG copper. Maybe mark it up 20 bucks for the half hour it would take me to spot weld the cells, solder the BMS wires, heat shrink it and drop it back in the post.
Not that it’s worth it to build a single pack, but if you are interested in building 18650 packs for other uses(repairing power tool batteries is a big one, as well as old laptop cells or making your own power bricks for portable charging) a reasonable non commercial use spot welder can be had for under $200 including the extension that allows you to do it away from the machine.
I think one reason they’re so expensive is they have to be warrantied and they have to offer support should something go wrong.
I’m trying to figure out a reasonable cost for a 10s3p lion pack with 30q’s. The material cost is about $200, without shopping too hard.
So if a 10s3p with 25r’s has a material cost of $140 and the average market price is $360 (low end avg), then the mark-up is $220. Add the 30q material cost to that mark-up and you have $420.
I couldn’t find anyone to make one for less than $500 and couldn’t find a ready-built at all.
You can order the cells from verified resellers overseas for much cheaper than they can be had in the states, maybe a group buy on materials could be arranged to negate shipping costs as well. Shipped from China or S. Korea 100+ 30Q cells or similar should be obtainable for around $4.20 each shipped and around $4.00 in larger quantities. I’d have to verify but I imagine quantities of 1,000 or greater could be had as low as $3.75 each.
You run the risk of fake cells even when they come from S. Korea, but it’s fairly easy to test when doing an initial bulk charge at 1.5A per cell. The fakes and old batteries being passed off as legit will be much hotter than new, properly stored 30Q or whatever. After identification you can remove the battery wrap of the potential fakes to observe the markings underneath and at this point if you’re convinced it’s a fake you can drain it and calculate the capacity. Then contact the reseller. This happens even with fairly reputable resellers and probably contributes to the cost of the 18650 packs you were talking about.
It takes me 2-3 hours of actual assembly time once I have the design finalized and all the materials in hand. My hourly rate based on my salary is $30 so at most $90. Most likely less, I build things for fun not for profit. My girlfriend and I love to build quadcopters too!
Gross… Reasons to DIY instead of buying packs…
I found them for around $5, in quantities over 25, here I. The states. But that is good info, thanks
I found them at $33 for 8. Dont remember the website but it was reputable according to endless sphere.
That’s why I build, not buy. Think about motor mounts, it’s $10 worth of stock and 10 minutes worth of machining, in fact you can cut 10 in an hour with $25 worth of stock and they sell for $30. Enclosures are $10 worth of ABS, sold for $60. 3D printed wheel pulleys, about $4 worth of material, sold for $30. All of that crap adds up fast!
Again, you can do that with Liions too if you decide to charge them with an RC charger, I did that for the past month while waiting on the BMS and charger to come from China. Over a month because of the Chinese new year…
I’m still kinda salty about that… LOL
Agreed, but that’s not something that is out of the realm of things you can do with Liions if we are comparing pros and cons.
And she’s also the reason all my hobbies have come to a stall lately hahaha.
I’m all for businesses making a healthy profit but $500 is freaking gross misconduct 
. But to does offer some explanation as to why some people lean twords lipos.
It’s like diesel vs gasoline. Diesel engines, as a whole, make better use of diesel fule that gasoline engines do of gasoline. Diesell is not to be had at every gas station, so it’s rairity effects purchasability.
I found them for $5.45 each, in quantities over 25, at lionwholesale.com.
SAMSUNG INR18650-30Q BATTERY 15A 3000MAH - FLAT TOP - WHOLESALE DISCOUNT, GENUINE AND TESTED
For 30 that’s $163.50 plus $12.15 shipping. Total $175.65.
I get the 500+ discount since we buy so many cells from them at work. Ummm here’s the link to the 33 for 8, http://www.gearbest.com/batteries/pp_399866.html
That’s $4.18 each, good deal.
Yep, I also continued our conversation on an edited post above. I have personally never bought from them since I have access to Liionwholesale discount but according to endless sphere they are legit.
