frontpage Posted by Navy-Wife | Staff • Jun 4, 2025
Jun 4, 2025 5:38 PM
Item 1 of 5
Item 1 of 5
frontpage Posted by Navy-Wife | Staff • Jun 4, 2025
Jun 4, 2025 5:38 PM
Rombica 2-Port Up to 75W Car Charger (1x USB-C, 1x USB-A) w/ 2-Pack USB-C Cables
& More$4.05
$8.99
54% offAmazon
Get Deal at AmazonGood Deal
Bad Deal
Save
Share
Leave a Comment
Top Comments
Looks like they're still selling the same model, and there's a father's day sale going on:
https://www.amazon.com/UGREEN-Cha...B0B3D9XW8
24 Comments
Sign up for a Slickdeals account to remove this ad.
Our community has rated this post as helpful. If you agree, why not thank Dave_B
Looks like they're still selling the same model, and there's a father's day sale going on:
https://www.amazon.com/UGREEN-Cha...B0B3D9XW8
Looks like they're still selling the same model, and there's a father's day sale going on:
https://www.amazon.com/UGREEN-Cha...B0B3D9XW8
up vote, thanks
Check if your car power ports shut off when the car is off. Many modern cars do this.
and what do you mean, "if left unplugged"? If it's not plugged in, nothing will happen.
Looks like they're still selling the same model, and there's a father's day sale going on:
https://www.amazon.com/UGREEN-Cha...B0B3D9XW8
Sign up for a Slickdeals account to remove this ad.
Thus I was thinking Max capacity would be 120W. 130W is confusing to me but I cannot talk about current technology or marketing with decades old education.
and what do you mean, "if left unplugged"? If it's not plugged in, nothing will happen.
I see. Well, my car's power ports shut off when the car turns off, so I can't speak to that issue. Maybe check the Amazon customer reviews.
Thus I was thinking Max capacity would be 120W. 130W is confusing to me but I cannot talk about current technology or marketing with decades old education.
All the cars I've owned/driven have used 20 amp fuses for the power ports. So, theoretical max power would be 240 watts. However, no USB charger is 100% efficient, so I'd guess the actual power limit for USB charger output is closer to 190 watts.
If your car uses a 10 amp fuse, you'd risk blowing it with chargers outputting 100watts. The exact number depends on the charger efficiency.
Also, if you use the charger when the engine isn't running, the battery voltage will drop(as it's not being charged by the alternator) and the current being pulled from the port will increase(amps = watts/volts). So, your laptop could be pulling 100watts from the USB charger on a 10 amp fuse with no issues while the engine is running, but when you turn off the engine (or if auto engine stop activates) your fuse might blow. On a 20 amp fuse this shouldn't be an issue for a 130 amp changer.
For reference:
-A car battery is generally considered dead or very low when the voltage drops below 10.5 volts
-To pull over 10 amps at 100 watts, the voltage would need to be slightly less than 10 volts.
LOL....so yes, when completely stranded on the side of the road with a dead battery and gaming or editing video on your laptop (to have it even ask for 100w) you could, in theory, pull 10 amps from a 100w charger. But I guess that is the way you could pass the time waiting for the tow truck
Sign up for a Slickdeals account to remove this ad.
For reference:
-A car battery is generally considered dead or very low when the voltage drops below 10.5 volts
-To pull over 10 amps at 100 watts, the voltage would need to be slightly less than 10 volts.
LOL....so yes, when completely stranded on the side of the road with a dead battery and gaming or editing video on your laptop (to have it even ask for 100w) you could, in theory, pull 10 amps from a 100w charger. But I guess that is the way you could pass the time waiting for the tow truck
You're assuming 100% efficiency in a DC boost converter, which is literally impossible. I have no idea what the efficiency of this device is, but if we assume 80%, then it would pull 125 watts from the car in order to supply 100 watts to the laptop. If the battery is at 12 volts, that would be 10.4 amps, and in danger of blowing a 10 amp fuse.
When the car is running, the battery voltage should be around 14 volts, thus it would stay below the 10 amp limit as long as you don't have any other devices charging at the same time.
I'm speaking from experience on this. Years ago, before USB-C, I used to run a laptop off an inverter plugged into the car power port. It would work just fine while the car was running, but blow the fuse nearly immediately after the engine was turned off, and that was a 20 amp fuse. So, I learned to unplug the laptop before turning off the car.
Leave a Comment