New item concept "automatic shield cell"

Automatic shield cell:

Design:

For so unfortunate I don't know how to design it but I can just tell what's the design:

Instead of shield being all blue will change it to white, And the white parts make black and delete energy mark in half and put two gear mark instead of it one is big other is small and near from each other and it is desirable that the gear mark be animating

What item actually doing:

U can only carry 2 automatic shield cell in the backpack, and it heals 25HP for the shield every 1 second until 5 seconds Maximum (125HP)

But! When u get shot healing will be slower 

So for example I pop auto shield cell then someone shoot me so the healing will 10HP every 0.75 millisecond untill you stop getting damage when u stop getting damage u need 0.75 millisecond untill the shield back normally and healing 25HP for 1 second until the rest of your seconds

I hope everyone got my point and I hope you guys will like my idea