MSC Eng developing cell replacement process

[Mark911]

Finally, I'm working on a bike that needs several P-groups totally replaced due to a failure with the balancing system. These groups discharged way below the low voltage cutoff, one totally dead! You just can't wake them up and expect safe, reliable and adequate performance after that. Necessity is the mother of invention, so here we go . . . . . .

Developing a process for removing the bottom heat sink plate for cell removal was quite a nerve racking experience. If any two of the negative end series groups somehow manage to touch one will short out (full discharge) and that's never a good situation. Cutting the bad cells out should be easy, but I'll need to develop a more robust method (beyond the one/two wire bond fixes I already have) for re-establishing the electrical connections with fuse wire.

I already have fixes for all the top cover failures and if I'm successful I'll have battery pack repair knowledge and processes for everything EXCEPT total cell replacement. If you are in need of individual cell replacement keep an eye on this tread as I'll report progress. If you need any other Alta related repair simply email me at maxvonauto@aol.com.

Work in progress. Please don't ask for any DIY details, the process is too dangerous and I don't want your injury or burned down house to be on my conscious!

Instagram @maxvonauto
Instagram @radmotoart

 

[Philip]

A small group of concerned citizens has reached out to me. They are very concerned about the safety of Mark and his property. They asked to confirm and clarify that this repair process has not yet been approved by the factory and is indeed very dangerous.

Kids, do not try this at home!

 

[Redwolf]

 

[B. FRANK]

if a man can put it together another man should be able to take it apart....I just know I'm not that man!!

 

[Fod]

I'm almost at your progress.... would have been there sooner if my annoying roof would stop leaking in my work space. Don't worry I took my shoes off before stepping in the drip bucket. Now ready to start separating the cells with my handy harbor freight power tools! Once I get the cells replaced hope to have time to fix the gas leak on my propane heater... stinks in here! Luckily I'm not stupid to use an electric heater with all these puddles in my garage work space!

 

[C5tor]

I just saw this post today, thought it was appropriate for the conversation.

 

[Mark911]

A small group of concerned citizens has reached out to me. They are very concerned about the safety of Mark and his property. They asked to confirm and clarify that this repair process has not yet been approved by the factory and is indeed very dangerous.

Kids, do not try this at home!

The warning in my original post speaks for itself. I appreciate the concern for my well being and I assure everyone that I'm very respectful of the awesome power and potential for damage that these (and any other) battery packs are capable of. Virtually a "controlled release" of energy equivalent to TNT!

Luckily, the major 18650 cell mfgs (Sony, Panasonic, LG, etc) have done a wonderful job reliably containing all this energy in a safe form factor and Alta did a good job integrating these cells in as "safe as possible" assembly. As B. Frank noted, if it can be assembled it can be disassembled/re-assembled. Obviously, in these cases not every aspect of the original build can be replicated. That's the nature and difference between a "rework to print" and a "repair". In satellite design and manufacturing we faced these "rework or repair" engineering decisions every day. The need to minimize program schedule and budget hits was weighed against the required operational reliability. At risk was potentially a failed multi-billion dollar satellite program, so decisions were not made hastily.

The key is always knowing the design intent. What the sensitivities of the design are and what factors can and can't be done differently. This applies to disassembly as well as re-assembly. Sometimes there's virtually no choice, no compromise. However, in most cases there's latitude to incorporate parts and processes that are "different" but still meet the original design intent, sometimes even exceeding them. Just because it's not identical to the original design doesn't automatically mean its inferior. In most cases the original design has other criteria that doesn't apply when reworking, like the need to automate the process for economical, repeatability, volume, or other reasons. That's why I made a distinction between replacing a few bad cells and replacing an entire module worth of cells. The disassembly and re-assembly precautions and quality of workmanship required to rework a few cells would be extremely difficult to repeat on a mass scale and the labor cost would be prohibitly high. It just wouldn't make sense from any perspective to do it that way.

Now, some may argue that I'm not aware of certain design criteria which make rework impossible. We'll I'm open to that, but as any engineer faced with the all to common retort "you can't do that" I ask why? What's the technical argument, the basis for not deviating from print? In my 30 years of designing, building, reworking, and repairing communication satellites with reliability and safety (when the shuttle was launching its considered a manned mission now) requirements exceeding 99.XXX%, I rarely encountered such an argument that proved true.

Again, thanks for the concerns for my safety.

 

[ElectroBraap]

Hmmmm, approved by the factory? We are the factory... Messing with high voltage is dangerous, that really goes with out saying...

I think we all know mark is plenty capable...

Electro

 

[Judaslefourbe]

I think we all know mark is plenty capable...

Famous last words

 

[ElectroBraap]

Famous last words

I think we all know exactly what this is about and I think it’s pretty uncool.

 

[Judaslefourbe]

I think we all know exactly what this is about and I think it’s pretty uncool.

I'm not sure what you're referring to but ok.

Edit: ha, you're talking about Philip's post. I don't care what Mark does, he's a grown man.

 

[VINSANITY]

Hey Mark, if you had the Alta battery case would that make the process easier

 

[Philip]

Liquid has the honeycombs too.

 

[privateer703]

I'm hoping he develops a process of replacing cells without having to buy any spares other than off the shelf materials. That countdown timer to CA's EV law is neat, but I can't stop thinking how that battery will hold up to 165 months, 26 days.... I would rather refurbish that battery than to buy a whole new bike.

 

[Motophyllic]

Mark, thanks for all your efforts in this. It’s great knowing I have some options if my battery goes bad.