Sounds like the ESC is losing track of where the rotor position is. Iād say try disconnecting your sensor wires (if you have them connected) or connecting them if you donāt. Might also be worth tearing apart the motors and replacing the sensors, they can be had from Digikey or Mouser for less than $2 each.
1 Like
Hi everyone,
Can someone suggest a good balanced BMS for a stock Raptor 2.1?
1 Like
Switching to Ack was the best decision i made. I donāt plan on going stock vesc tool ever again until they fix those damn bugs and stop telling me its a hardware issue. Thanks again @mmaner
7 Likes
doing a street build using dual 6355ās on a Landyachtz Wolfshark. thinking of going NESE for a battery designed more for torque than for range. if I want as lightweight battery as possible at 12s should I opt for 40t cells (12s2p rather than 12s3p 30qs)? looking at a few posts from the old forum everyone hates on 40t cellsā¦then a year later on here credible builds using 40t get hyped. wahts the dealio w these cells? Iāve no pref just wants a perf battery
4 Likes
40T cells perform better than 30Q cells one-to-one, but thatās far from surprising because 40T cells are 47% larger in volume. More room for battery makes your battery able to be a better battery, who knew?
The real metric for performance when comparing cells of different sizes must be size agnostic. A simple way to do this is to simply divide any cell spec by its volume, or by its weight. Looking at discharge graphs online, the curve of a 30Q discharging at 15A matches very well with that of a 40T discharging at 30A in terms of voltage drop vs capacity. Obviously the 40T goes longer, having 4Ah to the 30Qās 3, but the actual shape is similar.
Taking that info, you can say that a 30Q supplying (15A*3.6V=) 54W has similar performance to a 40T supplying 108W. Divide both numbers by the cellās volumes (or weights) and you get 3.26 watts per cm^3 for the 30Q, and 4.45W/cm^3 for the 40T, so we can draw the conclusion that the 40T is more power dense.
However, if we take the energy of each cell divided by volume instead of power, we get a different story:The 30Q has an energy density of 0.652 Wh/cm^3, whereas the 40T has 0.593. That means the 30Q wins in energy density.
What does all that crap mean?
- For the same size battery pack, 30Q will give you slightly more range than 40T.
- For the same size battery pack, 40T will give you slightly more power than 30Q.
- for the same cell count, a pack made of 40Ts will be nearly 50% larger.
Torque and range arenāt directly related at all. For the same power, if you want more torque, you have to give up some speed. Range is very closely connected to how much energy your battery has. More energy, gives more range, and more weight.
12 Likes
hardly seems worth it for 40t considering price/performance, in fact considering volume they seem almost the same. tho no doubt ppl will argue differently. but not surprising 30q appear on most builds and i guess for that extra NESE bulk 30q for my small build is the way to go.
as my first board I donāt have the luxury of experience with either cell, and it seems that 40t is choice made after an initial build, where you want something very specific. Iāll have to do the maths but I guess Iāll be working out which is less bulky: 12s3p 30Q or 12s2p 40T
1 Like
indeed 
and thank you for this, very clear info
4 Likes
i mean i depends where you live. in europe there is only 0.30 euros difference so 40t are worth it on a power hungry board.
1 Like
i live in Europe and i guess 6355 is relatively power hungryā¦ 
which battery supplier in Europe are you referring to?
Fogstar Wholesale. Search on the forum.
1 Like
ah those guys, last i checked the price difference between 30q and 40t wasnāt 0.30 euros, closer to 1. maybe i email the geezer for a deal or something
1 Like
because you need to go to fogstar wholesale
1 Like
if i flip a roadside fatcone to have the smaller diameter face the bushing seat, does that tame the initial response to turning compared to a normal barrel?
1 Like
40T is worth it for smaller P config. 30q starts to win more on larger P count.
40Ts are not 35 amp capable. They should not be discharged at over 25 amps or temperature becomes an issue. So 40T should really be compared to 30q on 15 amp vs 25 amp and capacity.
Itās a 25% increase in capacity. So a 2p 40T is 8AH vs 6 for 30q 2p.
Overall, it depends on the price you get them for. There is an improvement across the board. If youāre getting 30q for $3 and 40T for $7, then itās not worth it. But if there within $2 of each other, definitely IMO
2 Likes
Sorry, I could not find what you are asking. I see the comment about the FatCone. FatCones are designed to have the smaller diameter towards the hanger (bushing seat). Some trucks can accept them either direction and it is always fun to experimentā¦you might find something you really like by doing this!
4 Likes
It was in regards to @olsyke question. Maybe he can explain it better because i donāt really understand either
1 Like
basicly i like running my trucks on soft bushings, but the surfrodz tkp like to react really quick to uneven terrain or small bumps, i was wondering if i dont wanna choose a harder durometer, if a fatcone roadside would make them a bit more stable without losing out on final turning radius compared to a regular barrel
i think i will post in the bushing setup thread to get your recommendations for my setup, then maybe this will become a non-issue anyways 
2 Likes
A lot of people have a hardon for 30Qs, they are good all round cell but not the best fit for every job. I have a 40T pack on my AT board running 2 6354 and even in 2P its enough it wont get me up the steepest hills, i have built 3 x 21700 packs now and they are now my fav form factor. Cost and performance. You dont want to run 6354s more than 40 amps anyway so 2P (70 Bamps) is perfect especially in 12s.
1 Like