Automatic cell testing

Joined
Oct 8, 2016
Messages
31
I am starting to design a machine that can autonomously test 6 18650 cells at a time with minimal interaction. There will be a hopper on the top to store the cells, a wheel to collect and place the cells in charging/discharging slots, and a hopper below to store the tested cells. My goal is to have multiple charging "pods" at the top, with a hopper system to sort the cells by capacity. Most of the parts should be printable, with the exception of electronics, bearings, screws, and gears etc...


image_ubqcmx.jpg


image_bkyozl.jpg


image_bgckju.jpg



I plan on designing it in stages, my first step is to get the hopper working correctly. The holes around the bearing are for a IR position sensor and the grove in the middle is for the drive belt. Once I have a hopper that is working well I can get started on the charging electronics. I would want something intelligent for the charging/discharge/charge cycle so it can be recorded. Eventually I would like to figure out a way to autocratically mark each cell with its data and/or a serial number for later troubleshooting if I get a bad cell in a pack.

I am thinking about calling the project "The Revolver"

More images can be found here.
 
Very good, Mr Nerd is wanting to do similar .....

<!-- m --><a class="postlink" href="
">
</a><!-- m -->
 
Looks like your onto something here..
 
I do have plans on releasing all of the files once I have a working prototype. Here is my progress so far designing it:


image_okfkle.jpg


image_bjvrmo.jpg


I'll be printing the next part tonight and will be seeing how well the cells travel through the device. My current concern is the mouth to accept the next cell, I could get a group of cells stuck. I'll include a few IR sensors to make sure all the slots are filled and to detect a jam or an empty hopper.
 
I've been using Autodesk Inventor.


image_rbomno.jpg


I've been adding more detail to the model. There is now a rail for the batteries to run against so they don't get stuck between charging contacts. I've induced two spots for IR diodes to detect the position of the wheel and that a new cell is present at the start of the wheel. I still need to add a mount for the stepper motor.

image_xfxbgz.jpg


I've been printing out the slot where the charging contacts will slide in. I havent found a source for them yet so I have been removing them from some battery holders I bought from ebay. With my printer the overhang droops down and make the slot really snug. I had to apply heat for it to fit in, but now it is permanently attached and will never move.

image_eisnff.jpg


I printed a test version of the shell a few days ago and so far the cells travel smoothly.
8x6Yp8.gif


I still havent figured out what I am going to do about the charging electronics. I want something intelligent so the system can decide if the cell is good compared to a set of parameters. What would work well is something like a iMAX B6 charger, but in module form. Disassembling a Charger such as the SkyRC MC3000 or the Efest LUC Blu6 would also work, they can be hooked up to a computer via a serial interface.

I also need to start sourcing some batteries locally, I put the cart before the horse.
 
Sean said:
If you are in the UK I have a large quantity of cells which will not be used , I'd be happy to send you a quantity foc if it helps progress your project.

Thanks for the offer, but I located in the Western New York area.
 
Sean said:
If you are in the UK I have a large quantity of cells which will not be used , I'd be happy to send you a quantity foc if it helps progress your project.

Battery contacts are easy to find, again a UK supplier (and AA) :D but they are universally available.

<!-- m --><a class="postlink" href="https://www.rapidonline.com/trupower-dual-single-battery-contacts-71266">https://www.rapidonline.com/trupower-du ... acts-71266</a><!-- m -->

Is that offer open to anyone else lol :)
 
Sean said:
Chickey said:
Is that offer open to anyone else lol :)

If you've got an innovative project, yes

Not really, just a solar playhouse for the kids with builtin powerwall.
<!-- m --><a class="postlink" href="
">
</a><!-- m -->
 
Impressive design and implementation. But ...
Over designed. I have been involved in electronic mechanical machines for many years and at my company we always underestimate the physical aspects of things.

My best advice is - keep it simple stupid.

Make a long steep board and let gravity move the cells into position. No rotation motor. Endless capacity - just make the board longer. Cells will move forward without any electronics or sw.

Use a bicycle break to squeeze the poles of the cell. Use a car central locking motor ($10) to squeeze the bicycle brake. A plain relay board powers the motor. The motor closes the bicycle brake. The charge process starts. If the cell is bad another car locking motor kicks out the cell onto the floor. If OK cell the cells is advanced forward by gravity I a gate is opened.

Crazy idea for sure but make sure all physical movements of the cells are 120% fool proof before starting the electronic design.
 
It's an interesting idea, but I agree it's overly complex. And if you read my introduction thread, you know I am all for designing new things. But after all the work to extract the cells from the packs, You might as well take a minute and pop them all into a row of chargers. Some chargers will charge,discharge,charge again without intervention. BT-C3100 is one example. For $96 you can have 12 independent slots. And they will have resale value when you are done.
You seem very skilled and motivated, keep innovating :)
 
Back
Top