I have a used Bumblee Battery (8.0ah) for sale. Battery was producing strong assist until IMA light appeared. I did not attempt to grid charge or re-balance the cells, I just removed the battery. Battery has approximately 70-80k miles on it. It may respond well to grid charging, however it is being sold as-is. No guarantees whatsoever, purchase at your own risk, no returns.
Here is a link to the eBay listing: https://www.ebay.com/itm/113767412983
I will ship anywhere in the contiguous US for $70.
The core charge alone for this battery is generally around $400-500 with completely depleted 6.5ah cells.