The early Wellers (I still have mine, though I haven't used it in some time,
and don't know what the condition of the battery is) were perfectly okay for
light soldering. That was precisely the point -- in exchange for low output,
you got a cordless iron that couldn't electrically damage the components.
Which is why they called it "IsoTip".

If you expect to medium or heavier soldering away from a power line, the
propane -- I mean, butane (sorry, Hank) -- iron makes sense. For light
work -- especially small components -- the rechargeable iron makes sense.