There are a lot of high voltage to low voltage 3 amp buck converters on ebay, for 2.50 to 3.50 USD, just pick one that has a pot to adjust the output voltage down to 5 volts. ??
This is the one I use but there is another when available that includes a digital voltage readout that I prefer but was not available recently.
https://www.ebay.com/itm/125104160678
Bill P.