Paul from em3ev threw in a free Giant Green Button with our last $4,200 order so I could write a review for it because I was too cheap to spend $6 on one. It took me several weeks to get around mounting it to a build and try it but I finally did and was under-whelmed. This button is designed as temporary PAS cutout for the BBS02 so you can shift without grinding the gears and chain together.
Installation takes all of 5 minutes, you just hook it up to the ebrake connector and mount it on the left side of your handlebars. You will need to put it on the left hand side as your right hand thumb will be pushing the triggers to shift your derailleur. Since I usually mount the throttle on the left this made my handlebars feel pretty crowded on the left side and I had to mount the button inside the brake and the throttle so it was quite a stretch to reach it with my thumb (I have the longest and itchiest trigger thumbs in the West).
The biggest problem I saw with the green button is that it creates a 2 second delay of power interruption whenever you press it. When going up hills and you need to shift you end up losing way too much power as usually your shift completes in less than 1/2 second. The dedicated higo plug and the shift sensor on the Lectric Cycles e-Rad branded BBS02 works much better and is a far more seamless integration. That being said I would not spend $95 to get the shift-sensor from Lectric Cycles without having an e-RAD system drive because the power cut off delay will be too long and will probably be annoying, especially on hills.
When hooking up ebrakes to the BBS02 I never use the Bafang brakes on the rear-brake side. The main reason is because whenever you touch the brake the throttle stops working for 2 seconds. In the woods this is incredibly annoying to have constant throttle lag. I am often on the brakes and the throttle at almost the same time. If I leave the PAS connected then I hook up the Bafang front brake which allows me to kill the PAS immediately when I hit the front brake in case I’m about to hit something (that never happens) or I can just tap the brake a tiny bit but not engage it in order to shift. In my opinion this is a far better solution than using the Giant Green Button as it doesn’t clutter your handlebars and keeps your ebike looking as stealthy as possible.
The logo is what really kills it for me, Wuxing – The Five Punishments Of Ancient China (note the 5 stars above the logo). Gruesome.