Put a CAR Battery instead of those UX's

Thats exactly what I did on my 317 and 180. I then stumbled on some nice individual NiCad type cells of 1.35 volts each. I them made up several 12 volt batteries and held them all together with a strap of stainless steel. These were brand new cells originally used on building up aircraft batteries. The initial charge was tricky as each cell had to be monitored for reversal until it started to take a proper polarity charge, but I have a couple of those made up batteries still powering up stuff over 10 years now, and no sign of them giving up the ghost either. I ran one in my 1720 for years after original battery died, up until late 1999 or 2000 when I acquired a couple of the gel cell Optimizer batteries, and then installed them, but the nice thing about these fully serviceable and rechargeable NiCad cells is that there is absolutely no corrosion such as found on lead acid batteries, and battery connections and trays are corrosion free. I have seen these cells sold on the American Scientific website from time to time. Initially they have to be charged up using specific parameters and proceedures, but after that they are basically maintenance free. Have not had a dead or low battery in many many years.