How long for inverter to drain battery?

[emers382]

Originally Posted by PM15283

CPAP normally runs off of 110V, but with the right attachments can be made to run on 12V DC. Huge battery bank not usually adequate for all night.

We don't have an inverter other than a 140w to use TV or charge laptop. Beth uses a CPAP, 24v, was able to buy a converter for 12-24v designed specifically for the CPAP. Around $80 US I think but worthwhile and not having to change DC-AC-DC does not use much battery even using the humidifier function. Best of all our used 5.0TA came with a 12v outlet right at foot of Beth's side of the bed. Last time boondocking in the morning batteries were at 82%.

[John in Santa Cruz]

Originally Posted by sclifrickson

I just got a new MacBook, which uses a USB-C port to charge. I’m thinking about trying this for charging in the trailer. It would plug into a trailer USB outlet, then the USB-C to USB-C cord goes to the computer.

Attachment 41094

However, I’m concerned that the wiring in a USB port won’t be up to the task.

Any of our resident EE’s have thoughts on the matter?

THAT WILL NOT WORK

a USB 'A' port (the larger rectangular kind) has a MAXIMUM of about 10 watts (2.1 amps at 5V), and often many USB A ports are only 2.5 watts (500mA at 5V)

see https://en.wikipedia.org/wiki/USB_hardware#PD for the confusing set of options...
USB C high power configuration can run as high as 100 watts, using USB C Profile 5, with 5 amps at 20V, this requires a captive wire from the power source as regular USB cables would catch on fire running that much juice.

[sclifrickson]

Originally Posted by John in Santa Cruz

THAT WILL NOT WORK



a USB 'A' port (the larger rectangular kind) has a MAXIMUM of about 10 watts (2.1 amps at 5V), and often many USB A ports are only 2.5 watts (500mA at 5V)



see https://en.wikipedia.org/wiki/USB_hardware#PD for the confusing set of options...

USB C high power configuration can run as high as 100 watts, using USB C Profile 5, with 5 amps at 20V, this requires a captive wire from the power source as regular USB cables would catch on fire running that much juice.

Wouldn’t a fuse in the power center blow first?

Also, how would running it from a 12V cigarette style plug adapter, eg Jon linked above, make any difference, as both that and the USB are integral in same Escape fixture, using same wiring that runs to the fixture?

[John in Santa Cruz]

that USB cigar lighter adapter is current limited to the 0.5 or 2A at 5V. a high power USB C device, like your mac, has to negotiate the power mode with the power supply, and that cigar plug simply won't do that, so the mac wouldn't get any power at all.



edit: ok, if you're referring to this, https://www.amazon.com/gp/product/B003FOOY32/ thats a different thing entirely. thats a 12V to high power USB C direct charging adapter specifically designed for Mac's... yes, that should work. do note, 90W will be 7 amps at 12V, which is on the higher side for a cigar outlet, some will handle it, others won't.

[bdornbush]

Originally Posted by cpaharley2008

Why not just find the right adapter for the laptop. They all use DC for charging, seems wasteful to change DC to AC and then back to DC for the computer. I just plug mine into a outlet with the USB, it works.

That was my first thought but that limits me to one laptop, and now I have the flexibility to charge two laptops (mine and my wife's) and run any other 120v appliance that won't draw too much power. Most laptops take greater than 12v so there is still a DC-to-DC power conversion required. I haven't tested the various efficiencies of the conversions but perhaps I will.

[hotfishtacos]

Originally Posted by John in Santa Cruz

• I use a HandGround coffee mill to grind my daily beans
• I use a hand pour Melitta filter to make coffee directly into my stainless thermos tumblers, with water boiled on the stove or via my JetBoil Sumo
• if I needed to griddle breakfast, I'd use my propane stove
• My shaver battery lasts a month or more on a charge
• I've never used a sous vide cooker, can't that be done stovetop?
• I've never used an instant pot
• only smoking we've done has been with charcoal or on our propane grill at home, then frozen and brought on the road.

John, that's great! You obviously don't need an inverter!

[sclifrickson]

Originally Posted by John in Santa Cruz

THAT WILL NOT WORK

a USB 'A' port (the larger rectangular kind) has a MAXIMUM of about 10 watts (2.1 amps at 5V), and often many USB A ports are only 2.5 watts (500mA at 5V)

see https://en.wikipedia.org/wiki/USB_hardware#PD for the confusing set of options...
USB C high power configuration can run as high as 100 watts, using USB C Profile 5, with 5 amps at 20V, this requires a captive wire from the power source as regular USB cables would catch on fire running that much juice.

Just wanted to follow up on this. I had already ordered the little dongle adapter by the time that I'd been warned it wouldn't work, so I figured it can't hurt to just give it a try anyway and see what happened. It came in the mail yesterday, and so last night I plugged it into a 110 wall outlet that has two integral USB-A ports, so wiring to the outlet should be a non-issue. When I plugged the MacBook in it already had 100% battery charge, but the charging icon popped up anyway. I left the computer running doing some tedious maintenance tasks for some hours into the night and went to bed.

This morning I checked the computer and the battery had dropped to 49%, despite the charging indicator still insisting that it was charging.

So bottom line, yup, dongle is useless for charging a laptop. Bummer. Now what do I do with it? Maybe it'll work for a phone?

[bdornbush]

Originally Posted by John in Santa Cruz

I installed a pair of powerpole 30a each on it's own 30a fuse with 12awg...

Where did you connect the circuits?

[John in Santa Cruz]

Originally Posted by bdornbush

Where did you connect the circuits?

directly to the fuse panel on the two bottom fuses which are rated for 30A circuits...



(also wires for the dual USB to 1 15A fuse (really only needs like 2-3 amps), and the cigar plug to another 15A or 20A fuse)

[Ret.LEO]

Obviously it would depend on the size, type of battery along with rate of discharge.

[sclifrickson]

Originally Posted by John in Santa Cruz

THAT WILL NOT WORK



a USB 'A' port (the larger rectangular kind) has a MAXIMUM of about 10 watts (2.1 amps at 5V), and often many USB A ports are only 2.5 watts (500mA at 5V)



see https://en.wikipedia.org/wiki/USB_hardware#PD for the confusing set of options...

USB C high power configuration can run as high as 100 watts, using USB C Profile 5, with 5 amps at 20V, this requires a captive wire from the power source as regular USB cables would catch on fire running that much juice.

I’m still trying to see if I can wrangle charging a MacBook with USB-C but without the Mac power brick. Maybe this?

[John in Santa Cruz]

nothing with an "A" port can possibly output sufficient power for a macbook or similar, anything that meats the USB high power spec has a captive cord as putting 50 or 70 watts down a standard USB A to C cord would be a fire hazard.

that particular socket says its QC 3.0, which is Qualcomm's non-USB-standard spec forr around 30 watts max. QC is used by some cell phones, nokia, etc, mostly designed prior to the USB PD standard.


for a USB C powered laptop, you need something like this,
https://www.amazon.com/USB-C-Laptop-.../dp/B003FOOY32
or
https://www.amazon.com/Charger-MacBo.../dp/B073X5NNVS

[Vermilye]

See my earlier post in this thread (#20). As John notes, USB C chargers come in a huge variety of current capacities. I found a 30 watt will charge my 2018 MacBookPro as long as I'm not using it, but to both charge & operate, it takes at least 90 watts. You need a good quality 12V receptacle to draw 90 watts; some of the inexpensive add ons won't cut it, while the metal version that Escape provides has held up well.

When using a 90 watt power supply, I'd check for heating at the 12V connector often until I was comfortable with the connection.

[sclifrickson]

Originally Posted by John in Santa Cruz

nothing with an "A" port can possibly output sufficient power for a macbook or similar, anything that meats the USB high power spec has a captive cord as putting 50 or 70 watts down a standard USB A to C cord would be a fire hazard.

that particular socket says its QC 3.0, which is Qualcomm's non-USB-standard spec forr around 30 watts max. QC is used by some cell phones, nokia, etc, mostly designed prior to the USB PD standard.


for a USB C powered laptop, you need something like this,
https://www.amazon.com/USB-C-Laptop-.../dp/B003FOOY32
or
https://www.amazon.com/Charger-MacBo.../dp/B073X5NNVS

I was thinking about using the built-in USB-C port. This particular unit has both that and a USB-A port. The USB-C port won’t do it, you think?

[gbaglo]

Having destroyed a Grundig short wave radio with Radio Shack charger, I stick with OEM.

[sclifrickson]

Originally Posted by gbaglo

Having destroyed a Grundig short wave radio with Radio Shack charger, I stick with OEM.

That’s a good point. Was just hoping for a non-power brick, non-inverter option. But it’s sounding like it doesn’t exist.

[Vermilye]

Originally Posted by sclifrickson

That’s a good point. Was just hoping for a non-power brick, non-inverter option. But it’s sounding like it doesn’t exist.

It may, in time. The USB C is relatively new; I suspect there will eventually be higher powered wall mounts available. Look at the specifications of any unit; again, if they don't come close to 90 watts, they won't run a PowerBook.

[sclifrickson]

Originally Posted by Vermilye

It may, in time. The USB C is relatively new; I suspect there will eventually be higher powered wall mounts available. Look at the specifications of any unit; again, if they don't come close to 90 watts, they won't run a PowerBook.

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

[Vermilye]

Originally Posted by gbaglo

Having destroyed a Grundig short wave radio with Radio Shack charger, I stick with OEM.

My Grundig is/was destroyed by their fancy coating. A Buzz Aldrin version of the G6 on which they put a soft touch black coating. 4 years later, the coating is a sticky mess. I've experimented with many different cleansers to try to remove the remnants of the goo; so far denatured alcohol and lots of scrubbing is starting to work.

A great radio, but a terrible case!

[gbaglo]

I fried mine with reverse polarity. Radio Shack charger with 30 tips to choose from.