ChooChoo Short AT small batch GB_Completed

Anyhow all the decks for EU folks are hipped and the US are on their way @Sender with the enclosures from @BigBen. Great collab for sure :blush:

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I tried a 36" Evo a while back on a sweet build, and realized I need a minimum amount of real estate to feel planted.

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Not much… the neoprene compresses when I tight the enclosure bolts but I needed some space to fit the focbox dual heatsink…

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True but you should get the thickness of the xt90 at least. Those mm are gold in some occasions.

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Beautiful!

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I was spazzing out about this in the PM thread. Gonna bring it here (if you don’t mind @rey8801)

Revisiting this. Mostly organizing and tracking my thoughts.

For 21700, 21x9 == 189 which means 4.5mm relief on each side. The cells are cylindrical so we could route it at an angle or even curved. Lengthwise, 70x5 = 350 which leaves 80mm for esc and allows 13s3p.

I want nummies for this if at all possible. Don’t have a lot of personal experience, but expectations are needing more torque due to diameter, and wh/mile increasing 1.5-2x? So need both discharge-amps and capacity? Lol.

For me, I don’t need big top speed or huge range with this build.

cell layout discharge A wh difficulty notes
30Q 12s3p 60A 388.8 EASY
30Q 13s3p 60A 421.2 EASY
VTC5A 12s3p 75A 324 EASY
VTC5A 13s3p 75A 351 EASY
P26A 13s3p 75A 351 EASY better than VTC5A, on sale at $4/cell on 2/2/2020
LG HG6 20650 3AH 12s3p 90A 362 EASY on sale $2, wh calculated at 2.8ah/cell
LG HG6 20650 3AH 13s3p 90A 393 EASY on sale $2, wh calculated at 2.8ah/cell
30Q 12s4p 80A 518.4 HARD need to route, creative wiring
- - - - -
30T 12s2p 70A 259.2 EASY 30T can do 35A discharge. light. low range.
P42A 12s2p 60A 362.9 EASY 30A discharge 4.2ah/cell
30T 13s2p 70A 280.8 EASY 30T can do 35A discharge. light. low range.
P42A 13s2p 60A 393.1 EASY 30A discharge 4.2ah/cell
30T 12s3p 105A 388.8 HARD no routing, very creative wiring
40T 12s3p 75A 518.4 HARD no routing, very creative wiring
P42A 12s3p 90A 544.3 HARD no routing, very creative wiring
30T 12s3p 105A 388.8 HARD route ~5mm each side, easy wiring
40T 12s3p 75A 518.4 HARD route ~5mm each side, easy wiring
P42A 12s3p 90A 544.3 HARD no routing, very creative wiring
- - - - -
A123 M1A 15s2p 70A-ish 227.7 EASY lol! Have cells on hand. Tall.
A123 M1B 15s2p 70A-ish 247.5 EASY M1B is 2.5AH vs M1A 2.3AH

Nothing jumping out as a clear winner. Well maybe VTC5A 13s3p… I have 30Q on hand, and that’s a strong argument. But I can see arguments for 30T and 40T.

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fantastic summary! Thanks

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In space constrained builds, I’m always wondering if I could test before I commit… I have a VTC5A 13s3p board. I’ll try transplanting it to a hummie deck with avio drives to see what torque/speed is like.

I have a 13s4p 30Q board, maybe I can frankenstein that guy too, but that doesn’t answer any questions.

Like, VTC5A or 40T looks good unless 75A is not enough (unlikely), in which case it’s gotta be 30T. Can’t really fit 4p 18650 unless 11s.

Would prefer to keep it EASY.

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for the build evrything above 60A discharge and 12s is plenty. I am now making a new battery 12 or 13s3p with VTC6 because I am going to use the MAD Storm and they need more amp. I tried them at 12s4p 30Q and I was terrified. The current 12s3p 30Q is going to another build.

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OMG I added A123 26650 to the table. I think 15s2p will fit with a nice easy layout. I have a 15s2p powering hummie motors on my favorite build. I have loose cells on hand. Gonna have to test pneumies on it. Sorry hummie build!

How do you drive 15s?

3.3v nominal, similar to 13s.

Ah right. Overlooked at the cell type :blush: I thought I missed the presentation of a higher s counting ESC

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I can tell you’re thirsty for it. :slight_smile:

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Yeh an ESC capable of 16s would save me the extra time to make a 14s battery first and then upgraded with a 2s extra pack once the Esc is out.

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@Sn4Pz I added Molicel P42A 21700 to the table

The 13s2p is not bad. 30A is the continuous discharge rating, but it can do 40A with temperature monitoring. 393wh for 2p with ~70A discharge. I forgot what your requirements are.

P42A 13s2p 60A 393.1 EASY 30A discharge 4.2ah/cell

Ah I should mention for others in the thread, in the US the P42A is $5/cell until 2/4.

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I have seen these cells. Don’t know anyone that used them for out purpose. The specs are really good.
For me everything >= 60A discharge is good

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KfromtheBay found the flash sale. I’ve been blabbering about it in the battery builders thread. The discharge curve at 30A is interesting. Voltage drops real quick initially, then levels out. Much flatter than most cells, but you lose that kick of a pack just off the charger. :slight_smile:

For me, 13s2p of these is in the running, along with 15s2p A123 and 13s3p VTC5A. And 13s2p 30T which are also on flash sale, but the range is much nicer with these P42A.

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Added LG HG6 to the table. On crazy sale at $2/cell. 20650, so 20mm, which fits 9 wide in 180mm. Probably more like 20.1mm, which is 180.9mm at 9x. Should be easy 12s3p or 13s3p. Same/similar wh as 30Q but 90A vs 60A.

Dammit these guys burned me on the molicel flash sale…

I bought 13s2p worth of P42A, which has more capacity than 13s3p of these guys, and 60A should be enough. But… Maybe the 1mm height difference makes a difference?

Mr. @Sender do you think 21700 or 20650 will fit in the cavity?

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For the price and the bench test resukt I have see in not bad if the larger format is not a problem.

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