Several things can cause Battery Drain issues. You will need to isolate some variables in order to get a better understanding of what is wrong. The problem could be a bad replacement battery, excessive current draw from on of the modular components (camera, button, screen) or it could be a problem on the logic board itself.
Here are some things to try:
* It could be a bad replacement battery; there are lots of cheap batteries on the market.
## Try replacing with a known-good battery or order a good one from [product|IF128-027-2|here].
* You could have excessive current draw from one of the modular components; for example, the backlight, a camera or a sensor. You may notice a hot spot on the phone or screen.
## Fully charge the battery first.
## Disconnect the battery, then disconnect the flexes for the screen assembly, buttons and cameras, leaving only the Lightning Dock connected to the logic board ([guide|25869|follow this guide]). When you are done, re-connect the battery.
## Go back after an hour or more and test the condition of the battery. You will need to download either [http://www.coconut-flavour.com/coconutbattery/|coconutBattery] (Mac) or [http://www.3u.com|3uTools] (Windows) to see the battery condition.
* You may have a damaged logic board. This will require a micro-soldering repair and is not DIY. Drops, bends, water damage or using poor quality charging bricks and cables, can cause this.