I tried everything on this thread and finally I found the answer in this post: SMC does not recognize battery, battery charge indi. lights dont work! You have to disconnect the battery indicator cable. Some people found that you need to leave it disconnected. I found that I needed to disconnect it, boot up, shut down, reconnect it, and everything now works. Perhaps the battery indicator cable was loose. It’s a little flat connector near the battery, on the main board. You may need to google for pictures of it.