While cruising Craigslist for a bike for my son, I spotted a Tern Vektron D8. Apparently Tern moved from the original Bosch (still used on their higher priced bikes) to the Bafang M400. I'm not spotting replacement M400 batteries in the usual places .... anyone here have any experience with the M400 vs. the Bosch? Know of suppliers/prices for batteries (IMNHO, the most expensive most likely to be screwed up bit from an original owner ;>).

The Bafang website lists the battery as the BT C01.450.UC I see some of those being sold for $400. Did Tern use that battery?

https://www.bafang-e.com/oem-area/dr...-drive-system/
I wish it was easier to get the dealers manuals

Site says motor is compatible with all "customary" frames, but looks (to me) like it needs a specific "cradle" unlike the BBS series.

That looks like a nice model, if you need a battery Luna cycle seems to have some nice ones, I haven't used them but they look quality.

As it happens, I bought my son the bike. I can say with some confidence that the battery provided is D3611D.

... "luna cycles" ....

While certainly worth checking, it seems to be a different battery than used by any of the motors they carry, so color me skeptical. I imagine that means paying a serious premium via Tern (since even Bafang USA said they had no information about the M400 (since they don't carry it, I guess it's OEM only).