12V 120w Socket

You would blow a fuse in the car when using a two to one adapter and drawing 160w. Otherwise no damage.

Wiring something separately to the battery has the real possibility of discharging the 12v battery to the point the car won't start and or the 12v battery has to be replaced. However the 120w limit of the power outlet is no longer an issue. To avoid possible battery discharge a quality battery isolator is recommended. Those are sold as rv vehicle accessories.

The battery discharge issue is excessive parasitic draw of battery power when the car is off. An experienced mechanic could check for that after wiring in your aftermarket portable storage but aftermarket devices can behave one time and discharge your 12v battery another time. A quality battery isolator with 5ma or less parasitic draw is recommended.

 

Might be worth re-checking this. I'm assuming that "power generator" means a portable battery bank in this context.

A battery bank that draws 110W during charging is not one that I would characterize as "small," which makes me wonder if there's been an error in reading the specs.

The 120W limit applies to the fuse feeding the receptacle. The car can offer something like ~750W to the collective sum of all accessories, just not all through that one port.

Thus if you direct-connect one of those loads to the car's native 12v battery, you'll have the full 120W budget available to the lighter plug.

 

I took a look. From what I can see that thing can pull quite a lot in fast-charge mode, so you are on the right track to separate these loads.

 

More precisely, the car has a "DC/DC converter" that is able to supply around 1500 watts gross—including the power the car itself has to use. How much power the car itself uses will vary. When the car is sitting quietly in Park and is READY, it only uses about 400 watts, leaving a capacity as high as 1100 watts for you. When you have some of the hungrier accessories like the heat and defoggers and wipers and such in use, there is less left over for you. Under some circumstances when a lot of the car's own loads are in use (say the electric supplemental heat is on and you make a turn in a parking lot, heavy on the power steering assist), there may be nothing left for you—Toyota had little incentive to oversize the converter beyond the car's own possible combination of needs.

Exceeding the converter's maximum output on occasion probably does no lasting damage; its output voltage may begin to drop a little first, and under a prolonged overload it may shut off.

 

Yes.

An isolator can save your battery by automatically disconnecting your 110w load. If you direct connect the extra load and forget to disconnect a couple of times your 12v battery can be damaged. Maybe not the first or second time but…