So getting my Mooney M20C started in cold Wx is a royal pain in the six. I have engine preheating nixed for the moment, but am still struggling with the battery. If I keep it on a tender it works fine, but putting the battery box together is very difficult for me. If I leave it without a tender for even a week I haven't the power to get started. I'd leave part of a tender hanging out the battery box, but I doubt there's enough room to get anything out of there.
I used to have the exact same problem with my Cherokee, but the battery was under the back seat. The voltage drop was pretty big. That said leaving part of a tender hanging out was no big deal. The battery in the Mooney is in the engine bay, not a good place for anything to hang out.
Is this normal? It was for Cherokees, what about vintage Mooneys? Is my battery kaput? Is there a trick to putting the battery box back together?