My iPhone charge percentage jumps dramatically So sometimes my phone will be at 20%, and it'll die before going lower. Just now, it was at 4%, so I plugged it in, and it went up to 11%. After waiting 60 seconds, it's up to 34% now and has sat at 34% for the past minute or so.

What is wrong with my phone? It hasn't always been like this.
Non smooth charging or consumption indicates a hardware failure - usually battery related. If it's in warranty - that usually ends up the first attempt to remedy the symptom.