For those that have the common GX12 3-prong scooter connector, I found these on AliExpress: GX12 Metal Covers. I went with UPS shipping for $20, they ended up shipping fedex express due to COVID. I received them in under a week and bought 5 extra just in case.
AliExpress as a site is an absolute mess of an interface with popups and such, however, I couldn’t find these sold in the US anywhere. Also, there are a bunch of duplicate vendors that make it impossible to choose. I’d suggest the one I used above, since they had reasonable shipping options and did actually ship it using the selected option. That’s really the only cost…
I put these on my BKB Duo since my 2yo loves to stretch and tear those rubber ones off.
Suggestions where to pickup the fuse and amp rating? I’m guessing it’s not fused… output of the charger is 42V5A, so I assume just need 6-10amp fuse.
Although, I don’t think pins protrude far enough to make contact with the metal cap unless I flip it backwards … has that happened to you with these caps?
I’ve used all of those covers extensively and strongly prefer the rubber ones because they last much longer and are much easier to use. Though I don’t have a toddler tearing them off… that’d probably change my mind…
Be very ware of the metal ones. Firstly, they will likely get grit and crap on the threads and become very difficult to screw on and off and eventually just be really junky.
It’s extremely easy to short your battery out while fidgeting with the cumbersome cap, trying to get it threaded, especially after the threads get eaten up by road grit and grime.
Im using the same rubber ones and ordered the metal ones as well. First impression of the rubber are that they’re better but they popped open a few times while riding already.
Im using the GX16-2 as I couldnt see a reason for a third pin. I have some 4 pin versions as well im not currently using.
Id recommend re-making the metal cap in POM or maybe 3D printed and youll eliminate you short risks.
I’m not happy the fuse holder isn’t rated officially for >= 32VDC (since i’m running 10s, I really need 42VDC), but I can’t imagine breakdown happening at these low voltage levels. The rating is plenty high for the amps at least, so the parts shouldn’t warm up or melt. Its surprisingly impossible to find inline fuse holders rated over 32V! I did want to make sure the fuse wouldn’t arc while blowing, which is why I ordered the 58V fuses online vs auto-parts store which typically is max 32V.
I still think the over current protection in the BesTech D223 BMS would catch this kind of short, but it’s possible that interrupt wouldn’t happen until after some things burned up.
Thanks @b264 for the warning, better safe than sorry.
@bwahl602 if you happen to 3D print some GX12 screw-on covers, I’d like to pickup 5 of them from you.
The short protection may prevent damage to the battery. But it may kill the BMS
When a short occurs you’re more than likely going to see damage to the charge connector. After that the amps being applied will likely melt/destroy the pins and or the wiring for the charge port.
It’s important to consider that, if you wire charge port with larger than necessary wiring, youre eliminating a failure point that could allow a short circuit to continue where an appropriate wire will blow apart and minimize the damage done.
A fuse prevents all of this
