Have just got a colorspace UDMA2, [good, but not as good as my old JOBO gigavew]. It says that a car charger is available but gives no info about what to get. I like to use the screen quite a bit and am off soon to some very remote places so a car charger would give some peace of mind.
You can also use the coax port. I have such an adapter, but perhaps it came from the a Nexto I bought earlier. I carry an extra 18650 cell if power is expected to be a problem. A cell can be swapped out in less than a minute.