A bit over two years ago, those six 9 V 5.4 A·h lithium packs delivered around 4.5 A·h. They’ve been charged and discharged, run down until their undervoltage lockout tripped, severely jounced and bounced, and they still deliver about 4 A·h at 500 mA!

That’s a Good Thing, because I haven’t seen anything like those packs since then…
Never did get around to installing a cutoff switch, as we ride often enough that the penalty for not pulling the plug gets lost in normal use. The Wouxun KG-UV3D seems perfectly happy with 9 V delivered to its battery terminals, providing little motivation to hack into the battery case for a direct tap to the 7.4 V from the cells.