Will this kill my battery?
No. Unlike other ssh packages for the iPhone, this package does not have a constantly running daemon. It is simply added to the list of connections that the inetd daemon (which always runs on your iPhone) listens for. If it sees you trying to connect, it will start up sshd to handle it. When you disconnect, the sshd process goes away. This is exactly how it runs on Apple laptops. So, no, this package will not kill your battery if left turned on because, in truth, there is nothing actually running. My package is the only one that can claim this, to the best of my knowledge.