Quick Release Kill Switch

S

Suggs

100 W
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Sep 16, 2015
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Yorkshire, UK
For my kick bike scooter project I plan to ride it with the LiPo battery pack in a rucksack.

Similar to this:
[youtube]Ipu_-MTxiZY[/youtube]

To be safe (incase I get flung off the scooter at any point) I want a quick release system that will unplug the battery from the scooter without pulling the cables apart etc. A similar system to those used in Motorcross where the rider has a lanyard around the wrist and it's connected to a kill switch on the handle bars. eg: http://www.pitbikeparts.co.uk/safety-lanyard-kill-switch-engine-bike-p-2081.html

Has anyone come across something similar? Any ideas? I'm wondering if I could actually use the device I've linked to in some fashion? High current is what I'm a bit concerned with as I'll probably be hitting 50-70A peak bursts so the device will have to handle that.
 
SB50 Anderson connectors will do what you want. On CrazyBike2 I used them on each SLA back when I had the powerchair dri etrain on there, and once a SLA bounced out of it's containment on a test run, and it simply came unplugged rather than breaking the relatively thin wires I was using (that were bolted directly to the SLA).

THere are also larger ones but unless you're gonna run more than 50-60A all the time, I think you'll be ok with them.


The SB-type has been used for the lanyard-type killswitch on a number of vehicles, including racing motorcycles, etc.
 
amberwolf said:
SB50 Anderson connectors will do what you want. On CrazyBike2 I used them on each SLA back when I had the powerchair dri etrain on there, and once a SLA bounced out of it's containment on a test run, and it simply came unplugged rather than breaking the relatively thin wires I was using (that were bolted directly to the SLA).

THere are also larger ones but unless you're gonna run more than 50-60A all the time, I think you'll be ok with them.


The SB-type has been used for the lanyard-type killswitch on a number of vehicles, including racing motorcycles, etc.
Click to expand...

Thanks Amberwolf

I've not seen an SB50 Anderson before so I googled them. Do they form quite a loose connection? Purely from the photos they look like they are quite substantial.
 
On the Anderson website, there are spec sheets for the SB-series connectors and contacts, and there are two different contact types you can use with the housing, one of which has less retention force than the other.
http://www.andersonpower.com/_global-assets/downloads/pdf/ds-sb50.pdf
http://www.andersonpower.com/us/en/products/sb-sb-boots/

I don't know which version I have here; mine come salvaged from UPSs and powerchair stuff:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=67956&p=1024700&hilit=sb50#p1024700
file.php


file.php


file.php
 
For EV with controllers that has an on/off switch I would guess those kill switches would work just fine. As there are no high current on the on/off to the controller. If not you could use a relay of some sort if you could find one big enough to handle the current. Like you do on ICE cars when adding extra sets of lights.
 
I think a xt90s connector from your backpack to the bike is fine.
The connector comes apart easy enough in the event that you fall off the bike.
10awg wires will not tear apart before the connector comes apart.
If you are worried about damaging your wires during a fall I would get cable sleeves and wrap each wire individually then wrap both into a bigger cable sleeve.
You could use shrink tubing that has the built in glue to anchor the connector and sleeve.
Even add a few dabs of hot glue so that the cable sleeve mesh has more to grab.

uc


uc
 
I forgot to note that the SB series Andersons also have a wire-clamping ability, too, so that bending of cables doesn't cause contact-contact connection problems, or yank on the actual contact/wire connection. It's hard to see but it is a sandwich "T" of metal bolted onto the two holes in the SB housing, where the top bar of the T clamps around the wires. You could buy them or make them yourself. Mine came on the connectors as you see them.
 

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  • sb50 clamp.JPG
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Amberwolf, do you have any xt90 connectors to compare with the Anderson SB series connectors (in terms of the connection tightness)?
 
Hmmmm, odd. Mine are the anti spark version which might make a difference. The xt60's I have are also fairly tight though.
 
I dont' have them at hand, but IIRC from the design they are only possible to pull apart if you do it straight--if they end up at an angle they'd just rip the wires off the back instead, or probably crack the plastic around the edges or barrels if the wires stay intact.

The SB's will pull the wires too, but then they'll pop apart, and especially if you have that strainrelief clamp I mentioned before.

The housings of genuine Andersons are pretty sturdy--I haven't broken one yet, despite abuse, and actually even had a hard time using some wire cutters to trim some plastic off once. There are "clones" out there, too, and some are less sturdy than others, so I'd recommend getting genuine Anderson SBs.

If you have any friends in IT departments at places that use larger capacity battery backups and whatnot, they may even have old "dead" units laying around that you could scavenge the connectors (and cabling) from, and just splice your own wires into the ends of those instead of buying new ones and having to crimp or solder the contacts (cuz that's not that easy, given the size of these things).

Same goes for powerchair equipment; these things are common in both of those technologies (but not universally used, so you won't find them in *every* unit).

You can also buy them new from Powerwerx (assuming they sell genuine ones), or maybe even Anderson themselves, and probably lots of other places.

But if I were doing this, I'd try to find some used ones to test hte theory first. :)
 
Any of the andersons will work as a quick disconnect. At times, usually in the testing phase, I've stuck a battery in a pack or messenger bag for a run. 45 amps andersons work fine, stay connected fine, yet pull apart instantly when I dismount the bike for any reason.

I vote for andersons, snug, but release easy when you need them to.

2nd choice, 4mm bullets. Or larger if you need the big wire.
 
They also make fiberglass-lined silicone high-temp sleeve as well. (fiberglass on the inside)
 
Oh? Good to know. I know it's mostly a thermal barrier but I figured it was abrasion resistant too.
 
I do not have any more xt90s connectors to test but I was able to do holding strength test with a luggage scale and both popped out around 2-3lbs.
Having a few extra xt90 with cables already on them I wanted to demonstrate how strong the cable sleeves I got from china are.

uc

1st picture of xt90 with some short cables attached so that the shrink tubing had something to grab onto.

uc

2nd image is after I cut the cable sleeve to the length I needed I melted the end with a lighter and folded the end into itself to make a lip so that the shrink tubing can grab it better.

uc

3rd showed me stretching the shrink tubing so that it would fit over the xt90.

uc


uc

4th & 5th showed the cable sleeve completed.


uc

xt90 held by door while daughter @47lbs + ladder 5lbs
NOTE: There is no cable inside the sleeve this is a test to determine the strength of just the sleeve.

The shrink tubing was able to hold the cable sleeve onto the connector without coming apart even with my daughter hanging onto it.
Now imagine that with some 10awg cables inside and double sleeve.
I do not think you would have any issues with the cable breaking apart before the connectors do.

Here is a quick video I made.
[youtube]_ySYMsoz2SU[/youtube]

As I have stated in the video you can always take a blade an cut 2 slits on the male end of the xt90 to help it release faster or put some white lithium grease.
You can also cut the male end in half so that there is less plastic to hold the connector together. But if you do that then you would need to use that end for the bike and not the battery because you will have 2 exposed prongs sticking out.
 
Simon, what a legend you are going to that much trouble. Thank you.

You seemed to be giving the cable a decent tug to pull them apart but you've certainly proven it would work fine. I'll get some of the sleeve ordered and rig up my xt90-s and see what it's like.

Big thumbs up to your daughter too, hanging from the door on ladders :lol:
 
I have a big tube of dielectric grease, so that's probably what I'd use.
 
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