Wire strain relief?

[voodoosand]

I have an EM3V triangle battery, which has +/- wires exiting the rear (towards the seat tube). These wires get a lot of wear & tear and are often bent in a tight turn. I've already broken the pre-charge.
How can I prevent the +/- wires from breaking?

Inside the triangle frame bag I have 1.5"/ 4cm padding with cut-outs to prevent the wires from being pressed against the seat tube.
I've tried supporting with electrical tape, Sugru and small dabs of silicone. Nothing survives.

Current appearance:

Considering this wire strain, designed for power tools. Anyone have suggestions?

 

[goodgnus]

You need something that is anchored to the pack, too. You might take what you've got pictured and also take a thick-ish piece of rubber and make a flange with a hole that goes over the piece pictured. Then anchor that to the pack using silicone or other strong flexible adhesive.

 

[dnmun]

put a plastic sleeve over the section that is twisted back on itself to restrict movement. no reason you cannot cut some of that stuff outa the way to make the egress more straight.

 

[MadRhino]

On my FS frames, cables and connectors need to be replaced once a year. I never spent the time to route cables friction proof. I just route them where they hide best or at least, follow the natural frame lines. 8 ga wires are not fragile, but the weather, rub and crashes are wearing them dirty and corroded.

 

[amberwolf]

I put my similar pack in a .50cal ammocan with a slot cut in it for the charge and output wires, and haven't had to worry about the strain relief since then, despite daily movement and handling.

See the bike and trike threads in my signature for details; I think the most recent open-up and pics of the pack are in the CB2 thread from a few months ago.

 

[Avitt]

Do you remove the battery from the bag often? Or do you have to do much tugging or re-positioning of the wires when charging or connecting to the controller?

I've got an EM3EV battery in a bag. In may case, everything's strapped down tight (bag to frame, battery to bag, foam padding duct taped to battery), and stays in place.

 

[voodoosand]

Thanks everyone.
Avitt yes my setup is almost identical, but I do remove the battery 2x/day - once for charging at work, once for home. Wish I could keep it in the frame bag.
dnmum - problem is the wire has to be curved to some degree, tough to do a straight egress.
I'll take what goodgnus, amberwolf and others said and try some things. I ordered the rubber strain relief in my 1st post, so that may help. I think I'll definitely have to glue or mount something to the battery pack. I was hoping to avoid that.

Amberwolf funny you suggest ammo can - I spent a summer selling them by the side of the road in the middle of nowhere, so I have an odd hatred for them. No joke. They get nice & toasty in the sun!

 

[amberwolf]

Amberwolf funny you suggest ammo can - I spent a summer selling them by the side of the road in the middle of nowhere, so I have an odd hatred for them. No joke. They get nice & toasty in the sun!

I sympathize with that: here in Phoenix it gets pretty hot too. There are a few reasons I am using the ammocans: They're tough, and take some abuse before crushing, in the event of a crash or fall. They won't melt in anything that won't destroy teh battery anyway. If vented, tehy won't explode (theoretically) in the event of a dramatic battery failure internal to the pack itself, but should still contain most of the fire itself. And they're commonly available in many places in the world (unfortunately for the people/etc intercepting the original contents).

Unfortunately they are not a convenient size/shape for regular bicycle triangle mounts, but I don't usually use regular bicycle frames anyway. On those, though, they can still be used as panniers, or in front of the headtube, etc. Or a rear rack, though I don't recommend that as they're bad for handling and lots of racks can't even handle a few pounds.


OH, also, I usually run a separate plugin mount for my batteries to charge the bike from, so I don't have to plug in to the actual pack's connector. On CrazyBike2 it's tied to the frame and I just plug the charger into that. On SB Cruiser it's not finished yet, but it will do the same thing eventually. Then there's no changing stresses on the pack's connectors, and they can be just secured down and not worried about.

 

[teklektik]

This is just a matter of minimizing flex in localized areas. You should be able to do this with a little heatshrink/tape and a bit of wire splicing...

• Flip the battery around backwards in the bag
• Stagger-sleeve with heatshrink or tape in tapered fashion so flex is distributed over some length. Any tape will do, but you can get self-fusing rubber tape at Harbor Freight that should work well- you can build it up and mold it into a nice taper. (Do not get silicone tape - it's not abrasion-resistant).
• Securely tape the reinforced section of cable to the battery body - but not right up to the face - a couple of inches back would be good. Use duct or Gorilla tape.
• Plop it in the bag - you want a good 6 inches of the taper-reinforced cable protruding - the more the merrier.
• This may require extending the wiring - no big deal. Just insert a foot or whatever of wire and stagger the splices a couple of inches apart so you don't get a big slice-blob. There must be no splices forward of where the cable is taped to the battery body (near the zipper). The splices aren't flexible and will create wire failures - so keep them under or behind the battery-body tie-down tape where the wire isn't moving or up near the connector where there's not much flex required (skinny parts of the wire in the illustration).

 

[dequinox]

For those of you building your own battery boxes, or perhaps using ammo cans, here's a good wire relief product (often available water/weatherproof) you may not have encountered before: Cord Grips