How long for inverter to drain battery?

[John in Santa Cruz]

Originally Posted by sclifrickson

They claim it can be used for a MacBook, but max output is 36W.

MICTUNING 36W Fast PD USB-C Car Charger with USB Quick Charge 3.0 and Type C Charger Socket with LED Digital Voltmeter Compatible with iPhone iPad Pixel Samsung MacBook https://www.amazon.com/dp/B07LCBKZSG..._rGSzDbBCD7X47

as I read it, thats 18W out of each port, so the USB C port is only good for 18W. adequate to charge a phone or tablet, totally inadequate to charge a laptop.

even if it was 36W out of the USB C port, finding a USB C to C cable thats safe at 36W is another problem, most are only designed for 10-15W.

[sclifrickson]

Originally Posted by John in Santa Cruz

...finding a USB C to C cable thats safe at 36W is another problem, most are only designed for 10-15W.

I’d just use the one that came with the Apple power brick

Just read the fine print on it, which reads

“Output: 20.2V [DC] 4.3A (USB PD) or 9V [DC] 3A (USB PD) or 5.2V [DC] 2.4A”



Does this still mean that this


won’t work for a MacBook Pro?

[John in Santa Cruz]

your macbook pro will ask for the amount of power it needs. 20.2V * 4.3A == 86W is the max, that's probably the computer actively running AND charging its battery. once the battery is charged, the power requirements drop. if the computer is idle, the power drops. if the computer is sleeping and he battery is fully charged, the power drops to nearly 0.

I'm suspecting that USB-C PD adapter only supports 9V 2A (18 watt) and 5V 2.4A (12 watt) modes, and not the high power 20V 4A mode...

[Vermilye]

Apple sells a number of different lengths of USB C Charge cables (MLL82AM/A is a 6.6' version). They also sell standard USB C cables that are not charge cables. I don't have a link or part number, but they are thinner. I use one for my USB drive. While there is no problem using a charge cable for a peripheral device, I wouldn't attempt to use a standard USB C cable to charge.

[Mike Lewis]

I bought a few of those old blue Linksys routers at hamfests to use for experimenting with a mesh network and other things. They used 12V power, center pin positive. At one hamfest I bought a Linksys access point. It looked identical with the blue case, etc. I plugged it into a Linksys wall wart and a wisp of smoke came out. Oops. It was 12V, center pin negative. I have no idea why.

[John in Santa Cruz]

older linksys 5 and 8 port ethernet switches were 5V and were very prone to blowing out and dying. later ones of the exact same model were 12V and far more durable.

I *hate* those coax DC power plugs as there's like 30 different sizes and absolutely no standardization.