Default Battery error message at start up

Hi
Sorry if this was asked before, my new Galaxy S5 shows "For protection against water damage firmly seal the battery cover"
Every time I boot up or restart the phone. Then it goes away in 3 seconds.The battery cover and the charge plug are in place extremely snug and fitted correctly I made sure many times from cover and from battery seated well.
Is that normal ? My phone is stock non rooted UVU1ANCH
Thanks

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