I have an ark-pak 730. It is fitted with 120amp/hr AGM battery. The DC is not charging to the 7 amp capacity. When first used (purchased sept 17) the panel used to display approx 90 watts of charge, now the panel shows a max of 40-48 watts of charge when DC charging. I still have the same vehicle and the arkpak is still running the same fridge. I have checked input voltage and does vary anywhere from 11.8 to 13 volts. The battery voltage at charge test was 12.4 volts and showed about 82% charge. At the current charge rate it is difficult to keep the battery fully charged where as when first purchased the battery rarely got under 90%. The charge rate does quote 7 amps both on DC and AC but my calculation on 50 watts is 4 amps or less.
Gazza
Gazza