OT: using tablet as a Sat nav

There is no average car charger. Big screens need more power.

Is there a standard? I have a 13 amp socket with four of them - and one is marked 2.1 amp, and 5.1 being the total.

Yes original USB port was rated at 0.5A. Most phone USB chargers are now 1A.

I have a Goodmans 4 port car USB charger 3.4A on 2 ports for front seats and 1A + 2.4A for rear seats. Total 10.2A so it's going to be pushing the 10A cig lighter fuse. Got it at B&M at end of last year.

Install a charge/battery monitor app such Ampere to see for yourself.

With USB-C charging, my phone can run satnav and increase the battery charge on a long journey, but tends to be 'screen off' due to projecting onto the car's screen with android auto.

In my limited experience, car sockets are being uprated. I keep a cool box with bottled plugged in in mine. In the old car the water was just cool. In the present car, now 18 months old, the water is nicely chilled. I would suspect that the change was made in response to the OP's situation.

Replacing the car just because the USB port(s) aren't up to supplying a tablet is a bit excessive. Is this about to become the 21st century's equivalent of "when the ashtray is full".

All you need is £9.99 and a trip to B&M for a 4 port charger. Just don't have 3 kids, cos then you have to pick your "least favourite" to decide which one doesn't get a USB charge cable.

I nominate the under 10 year old that demanded to sit in the front. You just know it's parents don't love it.

Because it?s the unwanted mistake.

Be careful with cheap and cheerful no brand chargers.

I spent a lovely half hour with my arm embedded in the back of the glove box of my BMW trying to pull the right fuse to replace after a cheap charger took out all the accessory sockets in my car (which are all on separate fuses).

Not an experience I wish to repeat!

Look on Amazon, there are several higher output 5V USB adapters - eg 2.4A or more. One good maker is Anker it think - or similar spelling.

I don't know about a tablet but my Samsung S5 mini phone used to drain a fully charged battery with the phone still being continuously charged in around 5 hours when running the TomTom Sat Nav App. This was with live traffic update mode enabled and when regularly travelling in areas with a iffy mobile phone signal. The higher battery drain may have had something to do with trying to connect to an out of range (out of area) mobile mast.

TomTom did however have other modes of operation where the update rate was slightly slower and with a limited rendering of the graphics (street names not shown on the map etc.) that consumed less power.