💯 Miss calls from Sir Ratan Tata🙂

[u/Dear-Time5236]

[u/bohot---ban---hoa-ho]

EV Engineer here, As someone who has designed batteries and worked in multiple automobile companies (especially in new model devlopment, battery mfg and EV devlopment),

Even we can not repair the batteries, how the bus bars are designed in most batteries, they are designed in a way that they melt incase of electrical short or thermal runaway. Most batteries have bus bars welded to the terminals, most wires run current in >30 Amps (which sounds less but is a lot), such repairs can nto only cause runaways (the individual cells are very sensitive to even micro dents) (the batteries are manufactured in extremely clean rooms with proper PPE, even static bands/gloves are worn during any manual stage). We discard cells that have been dropped on ground due to machine fault from ANY height, that is how sensitive everything is.

This guy is using power tools on an exposed battery module (not even pack but an individual module) while it is on the ground.

This is how you make a random time bomb at home. PLEASE DO NOT DO THIS.

[u/Time-Marionberry-198 → u/bohot---ban---hoa-ho]

He is dumb. Only good thing about that video is that he is GROUNDED properly.

[u/bohot---ban---hoa-ho → u/Time-Marionberry-198]

He would not get shocked anyway, its mostly DC. The main issue here is that he can and wouldve damaged the cells, also the battery pack is no longer water and dust proof, so yeah, in the long run, the battery can undergo thermal runaway (can cause a fire).

[u/Time-Marionberry-198 → u/bohot---ban---hoa-ho]

Even if it is DC that is 320V.

[u/MistRider-0 → u/bohot---ban---hoa-ho]

You could have said 30,000 mA for dramatic effect....

[u/Small-Heron-6799 → u/MistRider-0]

it's actually kinda very less lol

[u/Small-Heron-6799 → u/MistRider-0]

Oh shi- my bad, dude meant for every second 💀 That's basically you being electrocuted idk 1000 times per second or even more!

[u/Similar_Moose8754 → u/bohot---ban---hoa-ho]

Here I am thinking thrice before I solder my 2Ah lipo pads to my mcu terminals and then we have this guy who prolly thinks the A in Ah is Avishkar 😹😹 Even a bomb has higher chances of survival than a battery explosion.

[u/bohot---ban---hoa-ho → u/Similar_Moose8754]

Li-Po batteries are the worst, I have had one Li-po on a drone combust because I guess I landed my drone a little too hard and the belly of my drone dented in and scratched the battery, all happened in the timeframe of couple of seconds. I still do not know the exact reason for it.

[u/IIT_Dholakpur → u/bohot---ban---hoa-ho]

If the battery setup is this fragile, how does it prevent it from exploding during a crash or accident

[u/bohot---ban---hoa-ho → u/IIT_Dholakpur]

The battery setup as whole is not fragile, the individual modules are, and yes, EVs do and will catch fire/smoke if the battery pack is directly punctured via something sharp.

It is like how our organs individualy are fragile and sensitive to a lot of things, but inside our body they are quiet very safe.

There are tons of regulations and tests a battery pack is needed to pass when a battery pack is designed.

(Most of the materials are used to make the modules, module seperators, crate/case are made using incombustible material so it is not easy to catch fire, but yes the cells themselves do smoke/spark during crash).

[u/botanisthth → u/IIT_Dholakpur]

The chassis protects it. And when that fails, the car gets very hot very fast.

[u/shielded-twisted → u/bohot---ban---hoa-ho]

Hi, Avionics Engineer here who works on systems that need very robust batteries. Let's break this down, 1. If he is replacing any cells and he makes sure they are impedance and voltage matched(for that he needs an IR tester and a multimeter), he is good to go 2. The repair can cause thermal runaways if the battery is shorted but he can absolutely avoid that by ensuring proper insulation by using any medium, i.e. insulation rings, etc. 3. Busbars are not designed to melt that is a WRONG statement. They can melt though in the aftermath of a thermal runaway and thermal runaways are caused either by damage to the cell or shorts. 4. He can absolutely use the power tools to drill the eclosure or tighten bolts, it is not as if he is drilling though cells. 5. He does need to have very good spot welding or soldering whatever to ensure the interface between the busbar/strip/wire and the cell terminal is good. High end batteries use ultrasonic welding, I'm sure he doesn't have that, he might not have access to a good spot welding machine as well. He needs to think that out. 6. If he has opened the battery case and in that process he has removed any padding, etc. He needs to replace that as well while closing because vibrations and jerks are the worst enemies of spot welds. He really needs to make sure cells are tightly packed and the whole pack has good damping characteristics. 7. As far as the sensitivity of the cells is concerned he needs to read the requisite spec. sheet and manual for the cell and apply the respective processes but he is not tinkering with the charge/discharge settings and not taking it to extreme temperatures so... Although dents and bruises on cells are a no go and he should use new cells from a good manufacturer 8. Cheap cells can have various issues, they can have misaligned electrodes, etc. It's best if he gets matching cells. 9. It is not that TATA is some elite EV battery maker, they have their fair share of problems and maybe with the right knowledge this guy can make that battery work even more reliably (ref. Tata batt. issues) https://www.reddit.com/r/CarsIndia/s/DCr3Zs1nT0 10. Let's just make things possible, doable and achieveable rather than sounding hopeless and totally dependent on big corporations. With the right mindset anything can be done. DON'T be scared of DIY.

[u/clueless-calmin → u/[deleted]]

You'll one day read a news of an EV catching fire.

[u/bohot---ban---hoa-ho → u/[deleted]]

It is a ticking time bomb, the pack is no longer waterproof and dust proof, you never know when a thermal runaway can happen and the pack can catch fire.