I don't know exactly how the OP intends to use the extra outlets other than to charge devices as needed on long trips. Since the Prius doesn't cost much to run, even when parked, I'd simply get 1 or more of the devices that have already been mentioned and not worry about tapping into the 12v battery. If anything, I'd tap into the power outlet on the floor of the console to run a line beneath the console to the back. I'd think there's enough room beneath the box inside the console to mount a 3-way splitter (like the one mentioned earlier) near the base in the back. I don't know though if that one circuit can handle 4 devices (the one that's there and a 3-way) if all ports were used at the same time. If not, maybe a completely separate circuit off the fuse box could be used instead. I'm considering doing something similar for the grandkids, but I don't want to cut into anything, so I'm thinking about mounting a box beneath or alongside the passenger seat so it faces to the back for easy access. I haven't looked at the bottom of the seat yet, but I've got to believe I could fashion a bracket to mount a box to the seat frame. Another option would be to run a long enough cord all the way to the rear seat and either just hang a splitter over the back seat or fish it beneath the pull-down rear console. I suppose a more elegant solution would be to mouth 2 ports, 1 on each side of the rear seats, but I don't know how much room there is behind the side panels. I already have a splitter with 2 power and 2 USB ports and I'm also considering an AC inverter with multiple power and USB ports. I already have all the gear and the splitter is probably all I'd need. It would use less power than an inverter and I could always plug the inverter in if needed.
I mean I don't see why what I posted initial wouldn't work? Are you running / charging a spaceship and all its accessories?? Lol. Even if you have 3 kids loaded into the back seat and they all have iPads. Run one of the 3 way splitters like I first mentioned a while back and each kid has a charger cord running from the center arm rest plug to the back seat and they can keep it plugged in at all times when on the move!? Why make things more difficult that they have to be..
I don't think anyone said it wouldn't work, I think he just wants something like other cars have with multiple outlets designed in. Our van had one in the cargo area and I've seen others with them on both sides of the rear seats. I personally wish Toyota had put the one inside the console on the outside for easier access and less chance of interfering with closing the top, crimping cords, having to take things out to plug stuff in, etc.
While I can understand the need for some to be entertained on long drives - I really think those days where kids were given time to imagine (without electronics), look at the scenery and be "bored" were/still important. As someone who conducts large, professional development sessions I am dismayed by the lack of concentration, or focus I see with folks perpetually using devices. They cannot function without them now which speaks to alteration of brain wiring in the form of addiction. My suggestion is: portion time during the trip for kids to get off the devices. Have them share a cross word puzzle/actual tactile game, look at license plates/makes of cars, imagine what it's like to live in another home/state and more importantly - develop and improve the art of verbal, face-to-face conversation.
I get it when a guy I meet tells me how a DVD player for the kids in the car is a "sanity saver," but like Bill Cosby said, you really can't call yourself a parent if you only have one kid. You never have to deal with "WILL YOU STOP TOUCHING ME!" from your kid...unless it has some serious issues going on. Unless your kids are subject to car sickness, I'd pack some books and make them read if they are bored. I'm okay with MP3 players so they can listen to their own music. Some of my most impressionable moments on family trips involved a hairy forearm reaching over the front seat to give me a thumping for not behaving.
My wife and I do crosswords while driving, it is much tougher if you never see the puzzle, just visualize it
I conducted a small social experiment up at Cape Ann. I took urban teens & chaperones (15-16 yrs - male) and made it a condition for them not to use their devices for 9-10 days. They were given 30 minutes a day to speak to their parents. If parents, or students complained about the rules - they would sent home. No one went home. I gave them a balanced diet (which they often help cook), no TV and filled their time with activities like kayaking, beach combing, hiking, visiting scientific institutions/libraries, see Harvard/MIT, conversations with teen peers from local exemplar high schools, minor chores + journal writing. The first 5 days were hard for them. After that they started changing in subtle ways - they started looking at flowers, insects, nuances of local architecture, gazing dreamily out the car window, verbally sharing their experiences & open thoughts with adults & other teens. Plus, they starting thinking about truly important things like their future & where they belonged on the spectrum. Returning back to basics is important in far too many ways - like focusing on the road while driving ; and especially for kids - returning to activities which advance them mentally and academically. Have them invent / play tactile games, practice speaking/the art of chit chat, return to day dreaming + getting bored. These are all components of developing and enhancing highly elastic brains. Twiddling on their little devices does little to nothing to augment strong brain development. And as I intimated - in my large scale training sessions I observe phone-addicted adults who have difficulty keeping up with projects / concepts that require out-of-the-box thinking and collegiality.
This is driven me nutz. why didn't they just put a outlet in the back. Spoke to a friend at a radio shop and he just put to USB outlet on the cup holders in the back seat for a customer car this sounds pretty slick. He's going to find out how much and get back to me on price and some pics.
Well I went with one of these up front And one of these for the rear I'll post pics of it mounting later I mounted it on the passenger of the center console and it worked out great. I don't hard wire it just used the outlet in the armrest to power it. It looks pretty clean I may hard wire it to that outlet later but now it's working out to be good and I didn't unrap the wire so it a neat little pile under the ararest in the center console.
