12volt charging of phone or tablet

[Concordia]

I find that my car’s USB has just enough juice to charge an iPhone slowly, but won’t do much with an iPad. The socket/cigarette lighter that feeds off my boat’s 12v battery is even less useful.
Is there a particular spec in hardware or installation to look for that will cure this problem?

 

[nootje]

Those are limited by watt usually, you can ask an Indy garage what can be done. Some cars, like a landcruiser have standard higher wattage on some outlets. Then there the option of building in a second battery which would allow you to even get a 120v or 240v here outlet somewhere in your car.

 

[Ixelles]

Are you using one of those little cylindrical USB converters in the socket/lighter? My car's USB is also useless but the converter charges the iPad fully in about an hour, and maybe 90 minutes when it's being used.

 

[Concordia]

My new-ish car has the socket/lighter and a USB. They seem to be equally feeble, although I've not found a way to measure that.

As for the boat, there is a socket that a friend installed some 15 years ago, which was mainly to power a dust buster. I'll have a conversation with the boatyard's electrician, but was curious if there was some "must be >X" stipulation I would need for an iPad Pro or other device.