Firewheel battery compartment measurements

[esaj]

Had to take some measurements from the battery compartments in the Firewheel in case of ordering the custom battery packs, so I thought I'd share them, in case someone needs them for whatever reason. Though in case I've measured something wrong, don't come crying to me...

These were measured from the INSIDE of the battery compartments. The fore- (frontside of the wheel) and aft- (backside of the wheel)  compartments seem to be otherwise similar, except the aft-compartment has 2mm higher width.

Height: 167mm

Width: 140mm (fore) / 142mm (aft)

Depth: Varies, lowest around 19mm (usual 18650-cell is about 18.35mm thick), near the wire channel connecting fore- and aft-compartments, deepest around 30mm.

There's a little bit room to add extra depth by putting something like 3-5mm rubber mat (cut into shape going around the edges) between the compartment and the cover, there's around 6mm (at lowest) between the battery compartment cover and tire (the picture showing the space between the tire and the compartment cover actually has more than 6mm, it was something like 8-9mm on that side, but the other picture showing the ACTUAL cover where the 6mm space was got out of focus).

Some pictures:

 

[esaj]

I needed to take the actual wheel apart (the above pictures were from the old empty shells that Vee sent with the wheel), to get measurements from the current BMS-circuit so we can (probably, hopefully) get correct sized new BMSs for the custom packs that will fit. I re-checked the battery compartment measurements on the new shell at the same time, and they are the same as above (except if my tape measure is wrong, unfortunately I don't have vernier caliper).

And if anyone needs the BMS circuit measurements, they are 62*67*9mm (roughly).

 

 

[dmethvin]

Thanks for posting all this info, it may come in handy for me one day. Can the BMS be positioned on one edge of the pack, or does it have to be in the center where it is? The reason I ask is that when it is in the middle like that it hits the small bump in the shell and makes the pack stick out of the battery compartment too much.

[esaj]

Thanks for posting all this info, it may come in handy for me one day. Can the BMS be positioned on one edge of the pack, or does it have to be in the center where it is? The reason I ask is that when it is in the middle like that it hits the small bump in the shell and makes the pack stick out of the battery compartment too much.

The deepest parts of the compartment are around the middle/little to the side towards the bigger bump. The concaveness of the compartment makes it difficult to get the BMS in place. 

I checked when taking the wheel apart, the smaller bump looks like it was meant to be used for a screw on the black round plastic part outside, but was left unused, I suspect one of their designers figured at the last minute that placing a screw there IS NOT A GOOD IDEA, as if it is screwed too far, it can puncture a cell...  But they still left it there in the compartment. The bigger bump is to hold the black round plastic part on the outside (the one where the silicone/rubber leg pads are attached to) in place, but I doubt it is necessarily, as it's already kept in place by many screws, and could be further attached by using double-sided tape or glue (double-sided tape might be better, as it's easier to get the part off if opening the wheel). Personally, I'll use Dremel or similar tool to remove the round bumps if necessary, once I get the battery packs.

Edit: I also measured the wire channels a bit last night, adding that picture here also:

Sorry that the texts are in Finnish, "n." = shortened from "noin", meaning "about", "Latausportti" = "Charger port", "loppumatka latausportille" = "Rest of the way to charger port",  "XT60-virtaliitin" = "XT60-power connector".