Wish I could be of help; have the same issue on L1520 but at least for me this is after I replaced the original battery. I haven't come across a solution since late 2015.
Same here
I'm in Europe and came across this issue with a Lumia 830, it's driving me crazy. So far I have bought three after market batteries, and all three exhibit the same 'blocked at 79% charge' symptom, despite being different brands (and one supposedly being a 'genuine' Lumia battery). Yet the battery originally supplied with the phone still charges to 100% no problem, so I assume that there is no hardware issue with the phone.
Initially I thought it might be a problem with the compatible battery I'd bought, but surely not with three different ones. I now suspect that W10 Mobile is somehow blocking a charge to 100% on these batteries somehow, but can't find any way so far to remove this charge 'ceiling'. :straight: