I spent my 4th of July checking things off this board’s to-do list.
Took off the enclosure, inside looks great after all the miles I’ve put on it. Odometer says it’s been ridden 373 miles. Doesn’t sound correct… (might be from freespinning when exiting the corner?) I have definitely been riding 30+ miles a week, ~200 miles is probably more correct.
BMS Power Button
The BMS needs a toggle switch for it to turn on and enable charging. My previous solution was taping the switch that the BMS came with to the outside of the enclosure.
Looks ugly, and the switch was starting to fall apart from the heavy vibration.
I have a switch that I salvaged from something (an ebike battery, I think?) that has a 36V LED and has a nice tactility
Reverse Engineering Rabbit Hole
I need to step down my 84V pack to 36V for the LED. The simplest solution is to add a resistor. But how big?
Having no idea the PN of the switch, I applied 36V from a power supply, and measured the current using a multimeter.
The LED draws 15mA @ 36V
Math Rabbit Hole
84V - 36V = I need 48V of voltage drop
Using ohms law;
R = V / I = 48V / 15mA = 3.2 kΩ resistor
To calculate the power it needs to dissipate,
P = V * I = 48V * 0.015A = 0.72W
That’s a non-negligible amount.
I only have 1/4W resistors on hand, so I’ll have to use a multiple. Double the power requirements for safety, and that means 6 resistors. I’ll put them in two series groups of three, to give more surface area for heat dissipation.
waves hands
[end math]
Math says 3.2 kΩ, so six 4.7kΩ resistors arranged thusly
I decided to try a new assembly method and use solder splices.
They’re basically heat shrink with built-in solder.
Cloe enough!
Splice on some mil-spec wire and solder to switch
Crimp some JST connectors onto the wires, and presto, the finished assembly (next to the old one).
The red plug attaches to the charge port +/- for the LED, but I didn’t add an extra plug when I installed the port. Fortunately, it fell off when I was drilling a new switch hole.
Pulled off the backshell and soldered two extra wires
Hell yeah, it works. Much better then before.
Huey is not amused
The grip tape in the rear has been abused with so much track racing
I removed the affected grip tape, cleaned with iso, and cut a replacement swatch of vicious. I tried to match the rest of the tape, pretty happy with my handiwork.
Hubba Hubs
I got some black Hubba Hubs from @HAIRYMANJACK (Thanks dude!! 
) I’m hoping stretched tires will give me more grip and help the tires last longer.
@poastoast sent me a file for Apex Jump drives → Hubba adaptors, Thanks!!
These things are incredible, S-tier modeling job dude.
I printed them in Polycarbonate.
Sadly I can’t get more then 3~4 threads onto the nut 
ehhhhhh not worth the risk. I’ll have to explore some other solutions… tbd.
Some other Updates…
Tires
Oh tires… tires… tires… I keep dissolving them.
This board is on the 4th set 
- First set of NOVAs- corded in ~160 miles. They were actually showing cords at the start of the 6-lab final at EE Long Beach, I was waiting for them to blow up. thank god they didn’t.
- A used set of Kendas. Corded in a week.
- Got a used set of NOVAs from @SinCityEsk8, corded em in 8 days
- A new-ish set of of Kendas. It’s been two weeks, still riding them. They’re starting to show cords, I’ll probably cord them on Saturday.
I’ve got a new set of NOVAs on the way, they’re going to be my race set for EE San Fran. I’ve got a bunch of Kendas that still have life in them(Thanks to @HAIRYMANJACK !! ), so I’ll be running Kendas until EE to keep my set of NOVAs freshy fresh.
I’ll conclude with these photos, from a fantastic San Diego group ride a few weeks ago
