How lame is a Tesla LDU without 400V?

[ImportFanatiK]

Having disassembled an 85kwh pack I now have an appreciation for the volume and weight of (16) Model S battery modules, and have come to the conclusion I cant fit all 16 in an RX8.
I think I can fit 8 comfortably (6 up front, and 2 in the back where the gas tanks were), which equates to 200V.

Could anyone offer any thoughts on what kind of performance one could expect with only 8 modules & 200V ?

Thanks!

[ImportFanatiK]

I think I found the answer:

https://www.diyelectriccar.com/threads/ ... st-1077237

https://www.diyelectriccar.com/threads/ ... st-1037875

[asavage]

The old Model S battery modules are nominally 25V, but they're fairly easily reconfigured with a little bit of Dremel work to be 50V modules. There's a YouTube video or two on this process.

That means you can use half the number of modules and still obtain around 400V.

[larsrengersen]

Maybe you want to read my blogpost before proceeding (and/or even recommending that option).
https://www.oldvolvo.com/blog/what-caus ... -car-fire/
Yes, it is possible and maybe even safe if you make 0 mistakes. But 1 mistake can have big impact (see above).
I choose that path back in 2016/2017 because there were hardly any energy dense options.
Nowdays it is a nobrainer. Plenty of options without any dangerous tricks!

[asavage]

Maybe you want to read my blogpost before proceeding (and/or even recommending that option).

I'm not sure to whom you're addressing this. Me? And the option? To modify a Model S/X from 50v to 25v?

https://www.oldvolvo.com/blog/what-caus ... -car-fire/
Yes, it is possible and maybe even safe if you make 0 mistakes. But 1 mistake can have big impact (see above).
I choose that path back in 2016/2017 because there were hardly any energy dense options.
Nowdays it is a nobrainer. Plenty of options without any dangerous tricks!

There are a lot of Model S modules available, at very reasonable prices, DIYers have been doing this modification since at least 2016. Yours caught fire but the most likely cause seems to have been a damaged cell; I don't see how this reflects upon modifying inexpensive 50v Tesla modules to be 25v.

[johu]

Back then we observed that Teslas themselves are not known in particular for battery fires. Also regular Tesla modules do not catch on fire when not grossly mistreated. So we started wondering what the differences were. The BMS surveillance was equivalently good, the cooling appropriate. The only difference was the stacking of the modules and the fact that they had been modified.

Of course the pile of ash didn't allow for a first principles root cause analysis so the modification just remains the most likely culprit, not the definitive one...
I think when recommending this setup, the Rengerson-story should be told along with it

[asavage]

. . . the Rengerson-story should be told along with it

???