b264
July 1, 2020, 2:07pm
1
Pocketable Fuel Gauges, let me see what you’ve got.
Discuss. Let’s see them and answer any questions about them.
This is one way to check a board’s charge level.
Other ways include experience, bluetooth/cell-phone, and ESC cutoffs. Oh, and of course building fuel gauges into the board itself. That’s so 2018.
5 Likes
b264
July 1, 2020, 2:07pm
2
I’ll go first.
12S LiFePO4 (hardwired) and GX16-3 male and female charge ports
this unit has since died, it was in my pocket during a streetface incident and cracked in half
this was the price I paid to learn to always set the VESC fault timeout to 40ms, not 500ms
GX16-3 male and female charge ports , selectable multi-chemistry, multi-voltage
A really old one , selectable multi-chemistry, multi-voltage, 5.5mm x 2.1mm barrel jacks, male and female
And a really new one, selectable multi-chemistry, multi-voltage, 5.5mm x 2.1mm barrel jacks, male and female
See how much smaller the new one is, with the same functionality Fits in my pocket much easier and more comfortably
3 Likes
b264
July 1, 2020, 2:08pm
4
A great thing about including the female jack on there, besides being able to watch it charge if needed, is this:
Plugging one of these into a charger will also let you know if it’s a float or a trickle charger
On a float charger it will kick on and off endlessly until you plug it in to the skateboard battery.
On a trickle charger it will just turn on and go to full voltage.
Most of the time float is better for skate use because it’s not roasting your cell balancer resistors while it’s plugged in and fully charged.
You can also quickly verify the charger’s actual voltage.
6 Likes
I definitely need to build one for my friend. He still uses his Evolve gen 2 board which has no Battery Led, gauge, meter or battery indicator at all so its always a question how long he has left to ride/charge.
3 Likes
For some reason “Roasting your resistors” got a good laugh out of me.
Have you considered a switchblade type action or a hinge for the male port to reduce the footprint? (3D printed of course)
This obviously goes against your elimination of failure points but I’m just interested.
I feel if this was purpose designed as a product it could be made very small.
1 Like
moon
July 1, 2020, 2:19pm
8
I like to live dangerously jk I shorted the charge port the other day so I printed this
18 Likes
b264
July 1, 2020, 2:20pm
9
I haven’t considered that, but I feel like if this was designed as a commercial product, it could be really small.
1 Like
b264
July 1, 2020, 2:21pm
10
disclaimer
For anyone reading, you should ALWAYS fuse your charge port and NEVER stick multimeter prongs into it. That’s really dangerous.
7 Likes
moon
July 1, 2020, 2:21pm
11
Its fused and theres I cant short it with this print…
2 Likes
b264
July 1, 2020, 2:26pm
12
Just have to put the disclaimer there, man.
You and I both have shorted out charge ports before… it’s not fun. Especially with no fuse.
5 Likes
b264
July 1, 2020, 2:42pm
16
Another non-obvious benefit of a design like this, with the flexible wire —
If you are at work or something and your board is plugged in, and your coworker trips over the charge cable, it’s a quick disconnect spot that simultaneously saves your coworker and doesn’t rip the charge port out of your board.
I use 30cm extensions on the end of the charger cable for that exact reason, but this fuel gauge looks like a nifty combination of the two.
6 Likes
b264
July 1, 2020, 4:39pm
18
4 Likes
I haven’t finished it, but using the same one.
4 Likes
b264
July 1, 2020, 5:34pm
22
I have some photos of this one under construction. It took about 6 coats of epoxy, 2 of which were thickened with fumed silica and 2 of which were strengthened with milled glass fiber, and 2 of which were smooth clear top coats.
This top patch was thickened, the bottom two patches were strengthened with milled glass fibers
This bottom middle part was thickened with fumed silica
and the finished product
b264: