Roadster battery (ESS)

[miimura]

All the cells connected in parallel are effectively one single cell at the same voltage, separating them to charge individually would provide no benefit. If some of those cells are completely dead and can't be charged then physically removing them from the pack and replacing them would, but that's a different issue.

My thought was manually charging each brick and evaluating its capacity before putting it back in the whole pack. Talking about individual 18650's is nonsense in the scope of trying to revive a bricked ESS.

 

[JRP3]

I remember seeing a forum where a (i think) company in the US brought these dead batteries back to life by taking the battery apart and charging cells individually.

That doesn't seem likely.

It doesn't seem likely to give a good result, but it also seems to the the only chance there is.

Talking about individual 18650's is nonsense in the scope of trying to revive a bricked ESS.

That's why I said it didn't seem likely. I just further explained that theoretically you could fix a dead pack if the issue were a few dead cells which needed replacement. I agree it wouldn't make sense to do so.

 

[TEG]

I think Tesla has some kind of machine designed to "reboot" a near-dead Roadster ESS, but I don't think people outside of Tesla have those.
So best bet is probably to inquire with Tesla service.

If the battery is too far gone, then it may not be possible at all. (AKA "Bricked")

 

[BartJ]

Hello everybody,

Does anybody has experience in bringing a roadster battery back to life? It undercharged due of the parasitic current while standing still. We are experienced in EV's but havent worked on Tesla's so far. I remember seeing a forum where a (i think) company in the US brought these dead batteries back to life by taking the battery apart and charging cells individually. But i can't find the website/forum anymore. Any help of advice would be very appreciated!

Thanks in advance,

Niels

Niels,
Parasitic current ?

what kind of virus is that.

 

[hcsharp]

Hello everybody,

Does anybody has experience in bringing a roadster battery back to life? It undercharged due of the parasitic current while standing still. We are experienced in EV's but havent worked on Tesla's so far. I remember seeing a forum where a (i think) company in the US brought these dead batteries back to life by taking the battery apart and charging cells individually. But i can't find the website/forum anymore. Any help of advice would be very appreciated!

Thanks in advance,

Niels

@spaceballs has done this. You can only do it if the cells are not too low that they have been damaged, otherwise it's dangerous. He has two methods as discussed in this thread:
Low Battery Warning; Charge Immediately
You have to trickle charge the cells at a very slow rate until you reach about 3.5v at which point the Roadster will be able to charge itself. Below ~3.5v the charging system can't charge them slow enough to do it safely because the PEM charging voltage doesn't go low enough.

If anybody attempts this, keep in mind it's very dangerous if you don't know what you're doing. At lower states of charge the cells become unstable and trying to recover them can have very bad results.

 

[JRP3]

To avoid any confusion what Spaceballs is describing is using low power external chargers bypassing the on board charger, not pulling individual cells and charging them.

 

[hcsharp]

To avoid any confusion what Spaceballs is describing is using low power external chargers bypassing the on board charger, not pulling individual cells and charging them.

Correct. Since the cells are potted in epoxy and have thin fuse wires on each end it's virtually impossible to charge individual cells. You could charge each brick separately with isolated power supplies but that would be 9 times more work than charging each sheet.

 

[supersnoop]

At lower states of charge the cells become unstable and trying to recover them can have very bad results.

And, just to be clear here, I believe "bad results" could include fire and explosions.

 

[spaceballs]

And, just to be clear here, I believe "bad results" could include fire and explosions.

If your lucky only one cells pops like in this photo.., else could be fire.

 

[spaceballs]

... Does anybody has experience in bringing a roadster battery back to life?

I've done it a few times, happen to know what voltages your bricks are at?

 

[hcsharp]

And, just to be clear here, I believe "bad results" could include fire and explosions.

Well said.

I've done it a few times, happen to know what voltages your bricks are at?

The $29,000 question...

 

[Roadster]

Low Battery Warning; Charge Immediately

I still haven't heard back from emachine.

@spaceballs, I read the other thread @hcsharp posted above with baited breath. Did @emachine (who was last seen on TMC "49w 4d ago") ever get back to you? Regardless of outcome... much respect!

Also (and no worries if you prefer to keep it as a skunkworks project), we'd love to see your in-vehicle charging setup.

Finally, the popped cell photo is a bit of a "Where's Waldo" exercise for the uninitiated but is it the one in the upper right that looks like a LifeSaver?

 

[IirisSeveri]

Gruber Power Services specializes in Tesla Roadster repairs and aftermarket products. We restore Roadster Propulsion Battery Packs, and provide Power Electronic Module (PEM) repairs, replacement, re-manufacturing, and a variety of upgrades to this critical item in a Tesla Roadster.

This ESS battery sheet came out of a used functioning 2010 Tesla Roadster Battery Pack with 23,000 miles and has been fully tested, charged, and holds voltage according to original specifications. It is a used battery pack with life left, and any resistive cells that could drain the bricks have been removed. We have two versions of ESS Sheets - with and without fuse. Please specify your preference.

Included is the Battery Management System board. All plumbing has been cleared and the sheet is shipped in a foamed box strapped to a pallet to minimize any potential shipping damage.