Do you mean the DC port in your car conked out? It could just be a fuse blew because some foreign material got inside of it. Or it the connections inside have worn out.
I bring a small power inverter on my trips to charge batteries and the like. The only problem is a power inverter is a bit larger if you are taking it on an airplane or something.
I use something like
this (I bought mine in 2011, so it looks different) for charging 12V items. It's a little tough to mount a battery charger, but you can twist it around. Should be available at you local big box department store.

Not sure about the new ones, but the fan noise gets a little annoying after a few hours. The charging light may be an annoyance when it's dark.
For the longer car trips with family, I have a bigger 170W inverter with a 4-foot cord. Plugs in three electronic devices without wearing out the alternator or battery, or charges my laptop. Don't just buy the greatest number of wattage for an power inverter; because if you load it up, you can drain your battery faster than your alternator can keep up.
If it can't get fixed soon, it looks like you're stuck buying a bunch of AAs.