Battery problem

mikkdcost

Hi,
Battery of my device don't work correctly. When he arrives to 15% device turn out in about 1 minute. I see that when I load the device, load indicator  sign 100% but if I remove and put in the battery, load indicator sign 85% of charge. I change the battery also with another original umi Hammer s battery but the problem, with other % il always present. I try with some cycles of load and with the updating of rom by official tool rootjoy but not one bit is change. How I can solve this problem?
Thank you.
Michele