FLX ebike battery failure

[paynef]

I bought an FLX Roadster in 2016 and used it sparingly for a year before a knee injury forced me to set it aside for 10 months. The battery had about 3/4 of full charge on it then. The battery is now somehow without charge. FLX tells me it is likely "flat." They suggest I send it to them to confirm it's "dead" and buy a new one.
I'm surprised a $400 battery is so delicate that it must be replaced because it sat unused for 10 months.
Does this sound proper?
Thx.

 

[www.recumbents.com]

Unfortunately lithium batteries must be maintained. The BMS that ensures that the battery groups remain balanced can also drain the battery over time. This is likely what happened to you. If the bike is not used for a long period of time, it should be charged about monthly, or the BMS should be disconnected.

If you are at all mechanically inclined, your best option now is to pop the battery pack open and measure the cell groups with a VOM to see how bad they are. One or more cell groups is too low for the charger / BMS to recognize. You may be able to revive that cell group by charging it individually with a cell phone charger.

Warren

 

[docw009]

The battery management system (BMS) shuts off the battery when any of the internal cells goes below its minimum voltage limit. If those cells went too far down, it could be unsafe to revive them. Fire risk.

FLX, for sure, would just scrap the battery rather than assume any product liability by trying to bring it back, and they're probably just an importer anyway with no real technical staff. $400 for a replacement battery isn't bad from an e-bike seller. That is the best option from a safety point of view.