The reason you don't find much on them is they are very $, something like 10times a simple isolator so most people just find it cheaper to replace their battery every couple years.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.