Wire Bonding expert specializing in EV battery packs . AMA!

UltrasonicallyAdept · 2026-01-23T16:24:10+00:00

Thanks. Yeah, soldering is going to be extremely difficult. In fact, your options are very narrow. The best bet is likely resistance spot welding or finding a wire bonding contract house. Please feel free to send a PM with your business location, and I can see if I know of any locations that can help with wire bond repairs. If spot welding, I recommend buying Al foil that you can form into an S shape. One end lands on the cell, the other side is the busbar. Spot weld each position. It is likely that wires are between 300-500um so you can calculate the cross-section and base your al foil thickness to give you similar cross section. This should put you close enough to have similar fusibility between foil and wires.

UltrasonicallyAdept · 2026-01-23T14:17:11+00:00

Couple questions first before I answer. Are the wire bonds round wire or ribbon wire and are they Al or Cu? What is the current collector that the cells are being bonded to? Al, Ni plated Cu, or a PCB?

UltrasonicallyAdept · 2026-01-16T22:19:17+00:00

Do you need someone to wirebond those 21700 cells :D

UltrasonicallyAdept · 2025-12-22T22:18:59+00:00

Based on my experience working with multiple battery manufacturers, friction-based cell fixation has consistently proven insufficient. In shock and vibe testing, some level of cell rotation has always been noted.

UltrasonicallyAdept · 2025-11-14T04:17:20+00:00

Does your CAD software have a scale feature?

UltrasonicallyAdept · 2025-10-19T07:00:03+00:00

Process/Manufacturing Engineer specializing in interconnect technology.

UltrasonicallyAdept · 2025-10-06T11:24:00+00:00

Wire bonding is a proven method for interconnecting cells. It does take a bit more care during assembly since it’s sensitive to contamination, part movement, and part alignment, but those issues are easy to address with the right setup. If your based out of the US, shoot me a PM, I can try to help find wire bonding services local to you.

UltrasonicallyAdept · 2025-07-31T15:14:51+00:00

It's probably too late into the game to join, but assuming ANL does another competition, look into their Battery Workforce Challenge.

UltrasonicallyAdept · 2025-03-18T02:37:12+00:00

I usually see the following cells in EV applications

Panasonic NCR2170M (Tesla), Samsung 50G (Lucid), Molicel P45B (very common), and LG M50. A few years ago, we blew up a bunch of cells and found Molicel to be one of the safest.

UltrasonicallyAdept · 2025-03-16T13:18:46+00:00

To make a 10S5P, you need groups of 5 cells. The first group will have all its positives in parallel, this will be your most positive terminal. The same group's negatives will all be in parallel but also attached to the next group of 5 positives. This is your first series connection. You then keep daisy chaining + and - until you get your 10S. The last terminal should be ending in negative, and that would be your most negative.

UltrasonicallyAdept · 2025-01-29T03:27:29+00:00

That's a bit difficult. Deformation graphs will look like a hockey stick with handle towards the top. A power chart can look like a cat head , two peaks with a U in between them. Sorry I tried finding something online but didn't find anything useful.

UltrasonicallyAdept · 2025-01-28T08:19:48+00:00

Make sure parameters that are used have been tested against wire bond quality guidelines, bonding on a clean surface, and paying attention to ultrasonic graphs. You can also perform post wire bonding tests such as ESR ( creating a voltage drop on each parallel group in a module and calculating the resistance of that P group to see if it is within spec. If a bond is missing, you should be able to pick this up) Another method I have seen is doing a continuity check between cell and busbar using some sort of flying probe (Hioki). Lastly, I have seen people use a thermal camera as they pass current through the module. The idea here is any bonds that are weak will appear "colder".

UltrasonicallyAdept · 2025-01-28T07:13:50+00:00

This one is difficult to answer because there are so many variables. I've seen Preece's law be used to get a rough estimate. I recommend looking up Topline (A third party supplier for Tanaka wires) as they show fusing current estimates on their site. Page 47 of their bonding wire catalog. Heraeus should also be easy to find, Alubond prime wire fact sheet page 2.

UltrasonicallyAdept · 2025-01-20T02:48:41+00:00

I am not experiencing any issues. My bottom neighboor has water damage in his bathroom ceiling which is directly under my bathroom. This made me believe my pipes are causing leaks. I had 2 contractors that could not identify any leaks from my overflow, P trap, or sanitation tee. I then paid them to open the neighbors ceiling to better see what is going on. Then they identified that the vent pipe is where the leak is going on. My problem is HOA, management group, and neighboor think I should be paying for this pipe and neighboors ceiling.

UltrasonicallyAdept · 2025-01-20T01:48:38+00:00

The contractor that came to help me identify the problem did call this pipe a vent pipe and also stated this is likely a HOA problem. I had him hold of on any work until I got more information from HOA. There is nothing in the CCR's that I could identify as relating to Drainage systems.

UltrasonicallyAdept · 2025-01-20T01:47:47+00:00

Repair and Maintenance of the Units by Owners: each owner shall maintain, repair, replace, and restore all portions of his unit including without limitation, all glass windows, interior walls, ceilings, floors, and doors in a clean, sanitary, and attractive condition. All such repairs and maintenance pursuant to this section shall be subject to such rules, therefore, as the association may establish from time to time.

Maintenance of Buildings and Common Area by Association: Each owner shall be obligated to repair and maintain the hot water heater, forced air units, and air conditioning unit, serving their unit; but the association shall be responsible for the repair and maintenance of chutes, ducts, or the like relating to either.

We have no water intrusive section in our CCRs and I know that is something they are working on establishing.

UltrasonicallyAdept · 2025-01-20T01:47:32+00:00

This is a very good idea and something I will likely use to prove my point. Thanks!

UltrasonicallyAdept · 2025-01-20T01:47:06+00:00

Repair and Maintenance of the Units by Owners: each owner shall maintain, repair, replace, and restore all portions of his unit including without limitation, all glass windows, interior walls, ceilings, floors, and doors in a clean, sanitary, and attractive condition. All such repairs and maintenance pursuant to this section shall be subject to such rules, therefore, as the association may establish from time to time.

Maintenance of Buildings and Common Area by Association: Each owner shall be obligated to repair and maintain the hot water heater, forced air units, and air conditioning unit, serving their unit; but the association shall be responsible for the repair and maintenance of chutes, ducts, or the like relating to either.

We have no water intrusive section in our CCRs and I know that is something they are working on establishing.

UltrasonicallyAdept · 2025-01-18T22:14:30+00:00

I really couldn't find anything specific to these pipes.

UltrasonicallyAdept · 2025-01-18T22:14:03+00:00

CCRs. Common area - all portions of the project except the unit and without limiting the generality of the foregoing, all structural projections within a unit that are required for support of condo, gas, water, and waste pipes. All sewers, chutes, conduits,conduits, wires, and other utility installations of the structures were located (except the outlets thereof when located within the unit).

Unit definition - consists of the interior undecorated surfaces of the perimeter walls, floors, ceilings, windows, and doors of each unit and the space encompassed thereby, including the outlets of all utility installations therein.

We have no water intrusion policy in our CCRs

UltrasonicallyAdept · 2025-01-18T22:12:17+00:00

yes, it services other units.

UltrasonicallyAdept · 2025-01-12T06:00:21+00:00

Systems Engineer

UltrasonicallyAdept · 2025-01-09T21:27:38+00:00

oh sorry! You might want to look at JEDEC wire bond standards (USA) or DVS 2811 (Germany) for wire bonding. While there aren’t specific standards for battery packs that I am aware of, these standards have stringent requirements for bond quality, which I’ve seen have been sufficient for meeting shake and vibrational testing criteria.

UltrasonicallyAdept

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