I built this tester to measure the condition of the batteries externally - otherwise the capacity determination was only possible in the bike.

In addition to 3D printing with PLA or PETG, some M3 screws and corresponding nuts are required.

The tester consists of 2 parts, the actual case with a screwed-on PLA0361 connector and a small bracket that is attached to the PLUS side as shown. This is only used to avoid confusion when plugging in.

As a reminder
PLUS is contact 2
Minus is contact 5.

For display we need:

Battery Capacity Indicator: https://de.aliexpress.com/item/32835915648.html?spm=a2g0o.order_list.order_list_main.22.66075c5fdyYuyJ&gatewayAdapt=glo2deu

For connection we need:
Reention PLA0361 Connctor:
https://de.aliexpress.com/item/1005006282520013.html?spm=a2g0o.order_list.order_list_main.39.7e3e5c5fJsfSby&gatewayAdapt=glo2deu