Hailong vs Reention

[Mindless Island]

I am looking for a Reention style battery that fits on a base that can accommodate a controller.
I was told by a well know e-bike tech company they’re dropping support for hailong and going with Reention batteries because Reention batteries are very common.
All I can find is empty Reention cases, few of which can accommodate a controller. That tech company does sell what should be a 400 dollar battery for 1000 dollars.

what am I missing? I have spent many hours searching and I feel stupid.

here are some hailong bases that can accommodate a controller. Those will need a battery where the pins are halfway up the case.

[Hootz]

There are some reention cases that have a spot for a controller. Go here: http://www.reention.com/en/ and go to the downtube battery cases. The tigershark, polly and atlas cases have spots for controllers but not sure how the case is laid
out. This retailer : https://www.fthpower.com/collections/reention-batteries sells reention type batteries and the shape of the cases are representative of what reention shows. The retailer may be able to provide more details as to the layout for controller storage.