I'm trying out an app called Battery Snap. I've been using BatteryLeft for a few weeks and while I like it, I haven't gotten an accurate Time Remaining since I got the extended battery. I recalibrated and right after a full 14 hours charging (3rd full charge on the battery) it says I have 10 hours left with 4182mV. That's the longest time remaining so far. It does run longer than that, but even with an "Accurate" reading it doesn't show much.
Battery Snap is a free app with some nice features. You have a choice of widgets, for example. It has a graph. It said I have 1 day and 9 hours when BatteryLeft said 10 hours.
I can't really say "Get rid of BatteryLeft" because it has some nice features. For one thing, I can choose what is displayed on the widget and the voltage is in mV, not volts.
Has anyone else used Battery Snap? You can see it at Battery snap v2.6.0 Application for Android | Tools