I have a similar problem and it has me stumped. I have a snap-on multimeter it measures amps through a clamp on the end model# eedm570. I was checking my 24v solar array and was getting anywhere from 6-8 amps from each panel except one. I immediately disconnected it from the others and I was getting 36V open circuit. But no amps.
Battery Chargers come with a range of features and differ in technology depending on what is required. Higher end models will charge 4 AA batteries in as little as 15 mins, while more cost effective options have charge times between 1 - 4 hours.