touching battery connector switched phone off

I replaced my old battery with teared connector (cut off)

with a brand new battery, my new battery “connector” is acting weird causing my nexus 5 switched off every time i pressed on it particularly!?

as shown in your Nexus 5 Battery Replacement

https://d3nevzfk7ii3be.cloudfront.net/ig...

I’m very upset and don’t know why pressing the connector makes phone goes off.

I've made a daily solution (piece of thick paper) to prevent myself or any outer knocks that making the connector been touched.

but still suffering of switching off my phone because of this issue.

please, give my any solution solving this issue.

Thanks.