What you are viewing does not mean that 50% of battery is gone. This shows where the battery usage is. So "cell standby" at 50% is normal. Meaning the 26 minutes since you pulled the phone from the charger, 50% of the battery that was used went to cell standby. That battery usage display is tricky, many people look at it and think that because the usage numbers are high, and the since unplugged numbers low, that the battery is draining fast. Not the case, add the numbers up, 100%. The battery is not 100% drained right, OK. It just breaks down what the battery has been doing since the phone was unplugged. This is not directed towards anyone, it is just to sort of explain the battery usage display, so nobody gets confused on what the numbers mean.