For the record I think lion is better due to range and cycle life. But it usually cost more and is more difficult to build a quality / safe pack then lipo.
Unless you need super high amp draw then lipo wins in most cases. Which is popular for heavy off road or race boards.
Lipo is usually cheaper depending on your sources and easy to make a parallel pack.
Lipo would only seem to be cheaper if I got for something like a 9s2p setup with the cheaper 30C or 45C (non graphene) packs. Which Iâm told may suffer from bad sag, along with its pretty short range.
These packs end up at around 2.5kg total, vs 1.5kg for an 8s4p liion setup. Theyre a little cheaper but not enough to make up for the weight/performance.
I plan to use nese modules if I go liion, which I hope will improve the chances of making something safe.
I use 12s1p 5Ah of the heavy duty hobby king lipos. Thatâs 70⏠per 6s pack or 140⏠per battery. Those are 60c and sag is pretty low. The range is average with 12-15km but well for that price not that bad I think.
Interesting⌠when I suggested using a 12s1p LiPo setup I was pretty much told it wouldnât work at all. Mostly if I ever needed to actually go up a hill, or use the brake. I did wonder how that worked, considering it still had loads more discharge than liion ever would, but I just assumed I didnât know enough about how batteries worked.
Pretty much everything from 6s to 12s works. Some even ride 13s on vescs. Sure if you run on the limits of components than the possibility that something fail is higher, but thatâs your own decision. With some cheap vescs like the Flipsky 4.20 and dual 4.20 itâs for now not really recommend to use 12s. But 10s isnât bad at all either.
Ah no sorry, I didnât mean that 12s1p wouldnât work because of too much voltage. I meant I was told it wouldnât work because of being too weak in amps and suffering from too much sag. (just repeating what I was told, I was surprised myself as it should have more available amps than liion).
The 12s1p seems to work out the same weight, and ÂŁ30 cheaper, than an 8s4p liion. The liion has a lot more range, while the lipo has huge discharge and charge rates. Thing is, nobody seems to have weighed in with how much discharge and charge is actually -needed-. I thought a VESC had a limit on the max voltage it could handle, so wouldnât 250A be totally unecessary? If the VESC can only handle 60A at a time, then wouldnât the 60A and extended range of a lion pack be more efficient? (I really donât know, these things donât seem to be part of the equations on this forum lol)
What actually is the number of amps charge rate required for consistent reliable braking on an eboard? It would seem like a figure everyone on here should know off by heart, but instead it seems like nobody has ever worked it out. It certainly hasnât been obviously written in any of the noob guides (I seriously doubt Iâve missed it in all my reading).
Liion 8s4p gets 12A, LiPo 12s1p gets 25A. Which would imply that LiPo would be more reliable for brakes. Except if braking only ever needs 6A or something, then itâs completely irrelevant because both packs will handle it easily.
did some more research before finishing writing this post After further research, it seems braking with -8A on battery and -50A on motor should work decently? So again, LiPo seems to add excessive charge rates that are never used, at the expense of range?
Dont get me wrong, Iâd prefer to use a LiPo 12s1p if it worked out giving more torque and braking ability like it implies by the ratings, but it seems to limitations are in the VESC (and also the ability to actually stay standing on the board).
Plus, I wonât be using the board every day, itâs likely it wont be used for a few days or mostly be used at weekends. And it seems LiPo will require much more supervision and being discharged for safe storage and only charged on the day of use. And being charged and stored in explosion/fire proof bags or ammo boxes, apparently. Which is fairly scary.
Honestly surprised there doesnât exist a battery that doesnât burn down your house just by being charged lol.
You will average draw 25-35A from the battery.
On peaks a bit more, but if you donât live in a super hilly area or go crazy off-road, you will probably never hit 80A. A 4p 30q in this case is totally enough. If you build a off-road only board I would definitely go higher in the p-count to hold the voltage sag down.
Donât get confused by the c-rating of the lipos. If you take a bit less of the half max discharge you calculate, you will get a realistic value from good packs. 60c 5Ah you can draw maybe 100-150A max from. 300A would probably melt down your 10awg wires anyway 
I see you doing a good work in researching and you right, if you just drive from time to time, get the LiIon pack. They damage way slower fully charged like lipos. You can store your board ready to go. With lipos you have to set them into a low voltage level each time you not going to use your board for some longer time.
One thing to add I forgot. If you set your bat min value to -10 to -15A per vesc you have pretty good brakes.
Haha yeh, I always massively research / overthink / overplan / overengineer any project I work on. This is why I usually end up spending more than I need to, and taking longer than I should, but usually I do end up with a pretty decent end result so itâs not all bad 
The area I live in is actually very flat in general. From my window there is a single hill, and itâs a landmark because for miles around it itâs all flat land. But then I also live near a place called cheddar gorge, which is an area with flat land, followed by a long sweeping/winding somewhat steep climb, followed by more flat land.
However much more common will be riding over short grassy areas like parks, as thereâs a lot of those around.
So, going back to the original question, but assuming the use of Li-Ion for the moment - Would I be better off with S or P for the âlight terrainâ use? Assume I can only fit 40 cells on my little board, so it would be 8s5p vs 10s4p.
I -believe- the 8s5p gets me more consistent power/torque on the hills/terrain, as well as less potential braking issues, while the 10s would get me a higher top speed⌠and thatâs all?
You will be happier with 10s4p. Better to drive conservatively on street and have room to throttle when needed.
What @venom121212 said. Get the 10s4p and motors with 170-190kV 1:4 gearing and 7-8â wheels and you will have a great all terrain board with nice torque, good brakes, average range and good speed.
1:4 gearing is where Iâm going (15/60T), and I was looking at the Maytech 170kv motors. I was also recommended the cheap motors from Dickyho, but Iâm currently waiting to hear back from him about whether he has access to a sealed motor. May be overkill but it seems for around here sealed motors might be less likely to get damaged. (I suppose I could come up with some kind of motor shroud though to protect from grit/sand etcâŚ)
EDIT: However one great side effect of todays discussion is that it is now decided that 4p will work for me. Which means I can start looking into and prototyping 4p battery enclosures.
So as far as VESCâs go, was the best bet to pick up two 4.12âs from ebay or similar?
Also for BMS, is the Dickyho waterproof BMS any good? Or is it required to get a Bestech for safety?
I have the sealed maytechs 6374 and they hold up pretty strong so far. If you decide to go that way, keep in mind they are a bit longer than usual 6374.
Regarding vesc, well you on a budget, so I think itâs clear for you that you canât get everything you want. If you get a Flipsky 4.12 or similar you will be limited to 35A max per vesc. After that they get hot pretty fast. Adding a heat sink can add some amps on top, but also add some extra moneys. Next step would be a Flipsky 4.20 plus. Should be good for 10s without cut outs. After that you could go up Flipsky dual 6.6 or focbox, focbox unity, but that might be out of your budget.
Focbox Unity current price isnât that bad, unfortunately it also doesnât exist and probably wonât exist for several months.
Flipsky Dual would be my next bet potentially. But again youâre right itâs not too cheap.
Correct me if Iâm wrong though (which I very well might be), but isnât the VESC amp max based on battery amps discharge, and not the motor amps? And as the peak discharge of my pack would be 76A, then 35A per VESC ends up being about right? Not much headroom, but Iâd probably find a heatsink version.
Your conclusion is right. The rating is based on the bat amps, not the motor amps. Thatâs why I said a hw 4.12 based vesc wouldnât be that bad if you on a budget and anyhow donât plan to hit it too hard. But well itâs never bad to run things somewhere in the middle of there capabilities than on the top or low limit. Oversizing in this case isnât that bad. @shaman is working on a improved version of the hw 4.12 for a good price which could be an alternative for you as well.
But here is also the BUT that itâs just in progress and beta testing will start only in one two weeks.
Yeh I already read through the cheap FOCer thread last night haha. Was promising, but Iâd like to be working on this now and hopefully be able to ride it over the summer months, and itâs looking like that wonât be ready until much later in the year unfortunately.
Dispite what some say lithium ion 18650 cells are nearly always safer. Nearly all have a current interupt device (CID), thermal fuse (PTC) and safety pressure vent on each cell! In fact if i understand the spec sheet correctly, you can short circuit a Samsung 30q, and it wont go bang. Within 20secs its current and voltage will drop to nil and its peak temp will only reach 100c.I dont think the same can be said for most Lipos. You can also individually cell fuse them, though theres debate on the benefits of doing so.
Also the advantage of running higher voltage is less current draw, my average current average is only 15a (Battery) on my mountainboard with 12s. Everything runs cooler. I think the consensus here is to stick to 10s max though.
https://eu.nkon.nl/sk/k/30q.pdf (See the short circuit page)
I should add that when you put them in series and the voltage is over 30v the CID can arc when activated and the PTC destroyed if activated, im guessing this is why tesla fuse there cells. This research doesnât seem to come up in forums.
I send on my mount solution once built, 200 x 100 mm aluminum plate isnt very expensive of ebay
So I have also found this VESC option - https://hobbyking.com/en_us/turnigy-sk8-esc-v4-12-for-electric-skateboard-conversion-w-bec.html, ÂŁ130 for a pair.
Not sure if its actually any different from the ebay option - ebay, also about ÂŁ130 for a pair.
Alternatively I can get a flipsky dual vesc for $240, but itâll be an import so have to add 25% on top of that for customs. So $300 = ÂŁ230.
A quick and dirty mockup of the space I have to work with. Itâs⌠tight. I mean too tight obviously, as it doesnât fit. The actual board is wider than that enclosure though, so I may just have to make my own enclosure that really gets to the edge of the board.