battery wobbling

cwah

100 MW
Joined
Jul 24, 2011
Messages
4,256
Location
Between paris and london
Hello,

I purchased a battery with lock and enclosure from bmsbattery and I realised the battery is wobbling even when locked. It has a noisy metal noise every time I jump anywhere and I fear it may break over time:
http://youtu.be/ju0l5MHss8U

Any idea how to fix that up

Thanks
 
I couldn't see the whole setup in the video, but one approach would be to make some kind of spring that takes the slop out of it. I'm thinking like a slightly curved metal leaf spring along one side that pushes it toward the other side.
 
where could i find this type of metal spring?

battery and rack can be seen here:
http://www.bmsbattery.com/48v/609-48v-15ah-lithium-ion-alloy-shell-ebike-battery-pack.html
 
Not sure what kind of bike you have, i have a chopper, so the need for something hugely secure wasn't too necessary for me...

I have secured my rack battery with 4x foam strips that i squeezed in between the rack and battery... holds perfect for what i need, but i'm not off-roading or anything either mind you... Used to rattle around so much, and eventually flexed the plate where the locking pin goes through so much that it is now useless... i've no need to remove the battery, so i have since bolted it in place to stop it sliding forward and back, the rubber pieces really just stop it from bouncing around, as it's not the tightest fit in the world to start with...

moskitobattery01_zps67f77bd3.jpg


moskitobattery02_zps8e292ed4.jpg
 
That pan that the battery slides on to, if you can bend the outer edges down away from the battery slightly it helps. Better yet slide a tapered piece of wood shim, called shim stock, in between the battery and pan. Something shaped like this http://www.amazon.com/s?rh=n%3A16413251%2Cp_4%3ANelson+Wood+Shims
 
My lovely ride is wrapped and covered with road kill bungee cord of varying lengths and diameters from stem to rear battery rack. When a bolt worked itself loose from the battery rack and fell off, I was able to keep going until I reached my destination by putting the end hook through the holes and running the stretchy cord around the rack several times. Try a couple of these hillbilly tourniquets for free an intersection near you. :lol: You can visit Harbor Freight or the 99 cent store to purchase brand new gimcrack, but typically they come with dodgy plastic hooks nowadays. :wink:
 
My thought was something like the picture below. Foam seems like it might work too. The flat spring would allow the pack to slide out fairly easily while taking up the slack. If you hit a big bump, it could compress the spring and still rattle.
flat spring.jpg

I have a similar issue with a pack I want to attach to a panier rack. Any bump is going to make it rattle around.
I found an old seat post clamp similar to the one in the pic below. I think I'm going to try making a metal tab with a slot that goes around the bolt and gets clamped down tightly when the lever is engaged. I would use a shorter bolt than the one in the pic. These things provide enough clamping force to keep it solid and it's still easy enough to release.
Quick release.jpg
 
Old office-sized laser printers by Lexmark, Brother, and HP printer trays and/or printers themselves have springs that look just about exactly like the pic Fechter put up with those three in it, used to trigger the microswitches that tell it which kind of paper tray it is (legal, A4, Letter, etc), and what's in it.

There are similar ones inside many adjustable-length medical products like crutches, canes, walkers, etc., and almost anything else that uses those little metal buttons to lock into a series of holes to adjust length. Many times the buttons are part of the spring, all stamped out of one bit of metal, but sometimes they are separate, whcih would make it easierto use.

Probalby lots of other places to find those things without having to buy new. :)
 
Ypedal said:
yeah, grab some plyers and bend the rail up and down in a few spots to tighten up the fit, if you bend it too much the pack will be hard to slide in and out :wink:

Hmm.. Interesting and risky too. Not sure I want to go down that road... :)
 
fechter said:
My thought was something like the picture below. Foam seems like it might work too. The flat spring would allow the pack to slide out fairly easily while taking up the slack. If you hit a big bump, it could compress the spring and still rattle.
View attachment 1

I have a similar issue with a pack I want to attach to a panier rack. Any bump is going to make it rattle around.
I found an old seat post clamp similar to the one in the pic below. I think I'm going to try making a metal tab with a slot that goes around the bolt and gets clamped down tightly when the lever is engaged. I would use a shorter bolt than the one in the pic. These things provide enough clamping force to keep it solid and it's still easy enough to release.


That seems interesting, do you have a picture of how it could be done? I'd like to explore this option
 
Try to find a piece of thin sheet metal and cut it out with tin snips, drill a hole near one end. The tricky part is getting the right curve on the bend, but like Y says, if you overdo it, you can bend it back. You can get a nice radius if you bend the metal over a cylindrical object of the right size (piece of pipe). The screw head has to be low profile enough to clear the battery.

I don't know exactly what the inside of the battery rack looks like, but anywhere you have solid backing and clearance for the screw should be good. I'd use two springs, one on either side, near the corner. Maybe even 4 springs.

Maybe a shape more like the one below would work better. A nice gradual bend where it touches the battery to minimize friction.
flat spring 2.jpg
 
I'm putting some glue on the whole to fill the wobble. I'll of course make sure the glue prevent to slide the rack in by slide it in it regularly:
2014-11-23%2017.50.36.jpg


If that doesn't work, I think I'll try to put some toggle latch:
http://www.ebay.co.uk/itm/4X-Silver-Suitcase-Case-Box-Chest-Spring-Stainless-Tone-Lock-Toggle-Latch-Clasp-/390856763593?pt=UK_HaG_Lock_Safes_GL&hash=item5b00e0e8c9

They are maybe easier to install than an seat tube quick release.
 
Put that stuff away man... seriously... grab some flat nosed pliers.. start at one corner, bend UP just a bit.. like a few degrees... move up half way, bend down.. repeat on the other side.. and try it.. painless, easy, quick and it's all you need to do... done it on a half dozen packs so far and works every time.

if you over-do it, the pack won't slide in or be very hard to slide.. just bend back until it's as tight as you need.

do this from the mounting plate . not the battery pack side.

not needle pliers (* they make a spikey notch.. no good ) , but something fairly wide like a half inch or so pliers.
 
Unfortunately I live in london and asking for someone in a car shop to help me will most likely to end up with a very salty invoice.

I'll get some measurement. Which plier is best to get?


Ps: currently glue is working
 
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