Why have I dealt with this charger for 13 years?

For me... I would get the IOTA DLS-45 or 55 model with built in IQ controller.

http://www.bestconverter.com/DLS-Series-12-Volt_c_144.html

You really want to max out charging to minimize generator time get the PD9270-14.8

http://www.bestconverter.com/9200-148-Modified-Deck-Mount_c_227.html

May need to upgrade the wire in the battery charging loop.