Charging spektrum dx3s via jack connector?

[Monkeysmate]

I don't seem to be able to get either of my dx3s TX to charge via the jack, rather than continually dragging 4 AA batteries out of each... I know that spektrum run reverse wiring for their jacks, but when I plug a jack into the TX, I get no voltage at all when tested with a multimeter.
I would have expected to get circa 5v from the AAs but not a sausage, which would on the face of it explain why I'm struggling to charge via the jack...
I feel that I'm missing something here?
Can anyone enlighten me please?
Ta

[mattr]

Neither of my dx3s have had the needed wiring from the jack. It's just a jack with no connections.

[mattr]

Thinking about it. With the two or three rechargeable battery chemistries available in AA size, it's probably quite a high risk from a liability point of view to have in device charging. Unless they were to provide their own batteries and charger. Which adds loads of extra complexity as some countries have odd rules about batteries/charging/chargers. So you'd need a special version for just that market