I purchased a replacement “extended” battery for the Galaxy Note 4. It’s a 7500 mAh extended battery by PowerBear. It’s suppose to give you 2.5x more than the default Samsung battery. The sacrifice is the extra size and weight. To be honest, it’s not that bad. Feels only a tiny bit heavier than my girlfriend’s iPhone 6 Plus.
The battery shipped with 58%. I charged it to 100% and used it until it was almost empty, about 5-10%. I did this 3 times. Last night I went to sleep at 2:00 AM with 100%. Woke after 7 hours with 97%. After 5 hours of heavy usage it’s got 73% left. So far a single charge has lasted almost 2 days of heavy usage. I’m impressed. Now my Note 4 lasts longer than the iPhone 6 Plus. The verdict? This battery is a beast in every way and will put life back into your Galaxy Note 4. Hope this helped!