Chosen Solution
I just replaced the battery in the A1522 iPhone 6plus model. But the life percentage still jumps around as it did before replacing the battery. It is the second time it has been replaced. I believe this is a software issue at this point. Can I get some direction on where to go with the issue to be resolved?
If you believe this is a software issue, then I would recommend a backup and then do a hard reset and if that doesn’t work, consider a full DFU restore. However this can also be caused by cheap batteries and a problem along the battery gas gauge line. This is the line through which the battery condition is communicated to the CPU. On older models, there was a tiny part next to the connector which could be accidentally pried off during a battery replacement. However, this is not the case with the 6 Plus. Perhaps the battery connector is damaged so you will want to look at it closely just in case.
