FarGrin -- Time to push some amps

[chuyskywalker]

Ever wonder how much the Grin Max45 can handle? I plan to push one hard.

Components:

• Grin Max45 Motor; std wind, ferrofluid injection; snipped connector for direct wiring
• Fucare Scorpio Frame
• Fardriver ND96450 (170 battery amps, 450 phase amps)
• A 96v (26s) battery (no details yet; awaiting frame to see how much I can stuff in it)

The rest of the build is likely to be pretty barebones and somewhat dull. I'm posting in the escoot/emoto section cause I likely won't bother adding pedals to it.

The battery may not have too much range capacity (and likely I'll need to use some absurdly high drain cells) -- but, it'll be a lot of fun to push the motor and find out just how much abuse these can take.

If it works out, I may go down the rabbit hole to see if I could get it legally registered as a Specially Constructed Vehicle. I always have the option of de-tuning it to something, ahem, more bike like and add in the bit's needed to get back to that. Or I could dual motor another ride Who knows!

 

[chuyskywalker]

Took advantage of the brief pause in tariff hikes, and now parts on the way:

• Frame, (bits and pieces like fork, wheel, etc)
• BMS
• Motor

Most of the rest I'm hoping I've got pars in the bin to get it going.

 

[bananu7]

I'm posting in the escoot/emoto section cause I likely won't bother adding pedals to it.

Makes sense. With a ~15kW power budget they're just a waste of space. I wonder how big of a battery you'll fit in this frame if it's meant to be 26s. 170 amps is comfortably within the limit of small E-series pouch cells in a 26s1p configuration, but it seems like you'll need to maximize volumetric efficiency and go with 21700 to squeeze something like 26s4p in there.

 

[chuyskywalker]

170 amps is comfortably within the limit of small E-series pouch cells in a 26s1p configuration, but it seems like you'll need to maximize volumetric efficiency and go with 21700 to squeeze something like 26s4p in there.

Yeah, I'm currently eyeballing some of these 70A 21700's like the EVE 40PL that can, apparently, handle 70A discharge. A 3p could do the trick (210A), but I'd certainly like to hit 4p for better overhead margin. Getting 26s4p (104 cells) onto the bike somewhere (along with the bms for that) could end up being a challenge. Heck, even a 3p build (at 78cells) is more than the largest pre-made case can accommodate.

I'm hoping the "cradle" shape of the frame lets me build a bit larger than the standard ebike battery shape, and then up a bit to get it to fit. Probably just hold the battery in with some ratchet straps or something, lol. It's a bit of a gamble, if I'm being honest.

 

[bananu7]

I'm hoping the "cradle" shape of the frame lets me build a bit larger than the standard ebike battery shape, and then up a bit to get it to fit.

Ah, just realized it's indeed open at the top. That should allow you to go a good couple cm above the top tube, and then 26s4p should fit fine, especially if you put the controller "outside", e.g. at the bottom.

 

[chuyskywalker]

Ah, just realized it's indeed open at the top. That should allow you to go a good couple cm above the top tube, and then 26s4p should fit fine, especially if you put the controller "outside", e.g. at the bottom.

Yup; one of the big reasons I picked this frame as a base. And I'm pretty sure I can jam the controller in that little triangle at the bottom. But I won't know till the frame gets off the boat and over to me.