Well, that’s interesting. Walked to work this morning with a banana in my pocket (this is not the start of a joke, BTW) and a spare battery for my HT. At some point the banana leaked onto the battery and in less than an hour has corroded one of the charger-side contacts quite badly! Beware bananas! It cleaned up OK with a fibreglass pencil but has taken off the bright plating leaving it as brass.