Shocking Battery Life

Peeps
I have had my Android 7 inch Scoll by Storage Options for 10 days now and just posing the question to you more veterian users about battery life.

Acording to the advanced battery indicator that I have got inatalled, shows that the battery dropping by 13% aa soon as I unplug the device off charge. !

Should I return it to maplins, or are there any tweaks I should try first. ?

Thanks in advance

Sent from my Android for Telechips TCC8900 Evaluation Board (US) using Tapatalk

 

I see my battery meter jump down by what looks like about that much too.
I think it might be one of those things we have to live with.