You can use an auto parts store (or Wal Mart) charger/maintainer and it will work OK, although when I did that in our
1960 Pacer I found that they don't last very long in continuous service, even though they claim to be built for it. (The Pacer didn't even have a coach battery as it came from the factory.)
My advice is to buy a good modern converter/charger like the Intellipower. They take better care of your battery than the inexpensive charger/maintainers and are built to do the job.
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