This is not an ad for Gruber but taken from an email they sent me -
Today’s topic - ESS Battery Pack Declining Range
Roadster ESS Battery Packs are going on 10-13 years of age. A
declining range issue is the new uptick in service for these legacy vehicles.
Individual cell failure, often one out of 6831 cells causes this often rapid declining range. Some customers who are used to seeing a predictable 150-175 miles range after a standard mode charge, are now seeing a loss of miles after each charge.
What is going on?What is happening is one of the cells is going resistive in a brick (99 bricks per pack). Since all 69 cells in a brick are connected in parallel, that one declining LI-Ion cell pulls down the brick, and since the Roadster Battery Management System (BMS) only charges to the lowest brick for safety reasons, a range decline is the result.
Option 1Take the Roadster to a Tesla Service Center. This will result in a diagnosis, usually corroborating a battery brick with a dying cell. There is also no external fix for this condition. Once a cell decline starts, is irreversible, and if left unattended by either life support (injecting DC voltage to keep the brick above 2VDC), or an immediate battery pull to isolate the bad cell, this condition will result in a dead pack, usually within one or three months.
The Tesla Service Centers are not equipped to do battery teardowns at the SC level. A battery pack replacement option will now be presented:
1 – Become a candidate for the new 3.0 replacement battery pack for around $29K. Recent customer quotes are projecting a 6 month wait for this long term solution.
Option 2If you have not taken your Roadster to a Service Center, email us a log file from the car. We can provide you a detailed analysis what is going on under the hood.
We have advanced log file parsing software that will pinpoint precisely which sheet and brick are failing, and provide degradation rates which helps establish inevitable brick timelines. We provide this service for free to the Roadster community. Click for instructions.
Our repair processFor us, this is a simple a sheet/brick straightforward battery repair.
Despite aged packs going on 10-12 years, the majority of owners are still able to drive their cars, and we have not yet reached a point where the packs just shut down from age. Although there will at some point be an expiration date, yet to be determined, an ESS pack repair is often preferred, since it allows the customer to continue to drive their Roadster, until a replacement pack from Tesla, is necessary.
As always, we work with Tesla Service Centers, and the customer, handling and coordinating Roadster transport.
Feel free to reach out to us for log file support, bricked Roadster CPR and immediate response, or just Roadster tech support and collaboration. 623-433-850