What’s the advantages for battery holder spring with nickel plating?

When battery holder is exposed in wet environment, the battery spring is easy to rust. So commonly we make some treatment with battery spring, for example nickel plating. So I have listed some advantages for springs with battery holder.    

1. The stability of nickel plating layer in the air is very high, because the metal nickel has a strong passivation ability, can quickly generate a layer of very thin passivation on the surface. It can resist the corrosion of atmosphere, alkali and some acids.  
  
2. Electroplating nickel crystal is very small, and has excellent polishing performance. The polished nickel coating gives a mirror-like sheen, therefore nickel plating is a good surface treatment with appearance.

3. The hardness of nickel plating is relatively high, which can improve the wear resistance of the surface of products, so our battery holder spring can bear many times of installing without damage to the spring surface.