Amp usage - Page 2

Islandpeople · 06-19-2019, 01:06 PM

They say not available in Canada. Looks like we'll have to carry on as we have. Thanks for everyone's input.

cpaharley2008 · 06-19-2019, 01:31 PM

When I suggested USB, I meant the cable with USB to plug into the Escape USB charging station, the other end would be specific to your computer. It is possible you can also find one that will change your computer using the round cigarette type charge end.

padlin · 06-19-2019, 02:03 PM

Is there such thing as a laptop charger that works off a USB? that's only 5v. The lighter style are 12v.

caddoster · 06-19-2019, 02:18 PM

the newer laptop that uses usb-c to charge will work on the usb port, but depending on the specification of the Escape installed usb port (amp output) it might not be charging as fast.. for the older laptops/devices the 12v charger is probably still the better way to go since the cig plug usually can do higher amp draw.

Brian B-P · 06-19-2019, 04:01 PM

Quote:

Originally Posted by cpaharley2008

... you do realize your computers are 12v appliances and that you are converting 12v to 120v which the computers then change back to 12v for their operation? Very inefficient use of 12v.

Few of any laptop computers will run on 12 volts. Yes, it's not ideally efficient to convert 12 V DC to 120 V AC then to 19 V DC, but even a charging adapter that plugs into a 12 V DC or USB port will be doing a conversion with less than perfect efficiency.

cpaharley2008 · 06-19-2019, 05:09 PM

Brian, both my MacBook Pro and my Mac Air operate and charge off the Escape 12v batteries without issue, as does 2 iPhones without any problems. I do use the higher 2.6 voltage USB plug. As far as time to charge, I'm not concerned but eventually they reach 100%. IBM computers should not be much different.

sumac.rhus · 06-19-2019, 08:03 PM

Quote:

Originally Posted by cpaharley2008

Brian, both my MacBook Pro and my Mac Air operate and charge off the Escape 12v batteries without issue...."

What charge cable do you use for your MacAir?

rubicon327 · 06-19-2019, 09:13 PM

Quote:

Originally Posted by caddoster

the newer laptop that uses usb-c to charge will work on the usb port, but depending on the specification of the Escape installed usb port (amp output) it might not be charging as fast.. for the older laptops/devices the 12v charger is probably still the better way to go since the cig plug usually can do higher amp draw.

The Magnadyne 12V/USB-A plugs installed by Escape have a charging output rating of 5V/2.4A and can provide that to both ports simultaneously.

Ronn · 06-19-2019, 09:26 PM

Quote:

Originally Posted by cpaharley2008

Ronn,
You do realize your computers are 12v appliances and that you are converting 12v to 120v which the computers then change back to 12v for their operation? Very inefficient use of 12v. See if you can find 12v USB charging cords, then you can just plug them into one of your USB outlets and bypass the inverter. Your batteries will last you a lot longer and you will only need the inverter when using the convection appliance.

Great, thanks much Jim! I've been thinking that there might be a 12 volt solution. We have been boondocking under cloudy skies and with a canopy of tall trees. It has been raining off and on all day and tonight it is raining hard and steady. We used the furnace tonight (felt very good). I talked with a fellow camper today and he loaned me an allen wrench, now the pump is performing as designed. All is going good.

Ronn · 06-19-2019, 09:39 PM

Quote:

Originally Posted by padlin

Here's a 12v charger for the Aspire.
https://www.amazon.com/CAR-Charger-4.../dp/B002TOFK2S

And here's one for a Satellite.
https://www.amazon.com/PA3516U-1ACA-.../dp/B002VANJ4Q

These are NOT usb, you need to use a lighter style 12v socket, if they still put them on the trailers, and I believe they connect to the regular charge port on the computers. Do verify these are correct, there are many styles of Aspire and Satellites, connectors may vary.

Being as how you are a fairly heavy power user I'd suggest you get a decent battery monitor and learn what's really going on.

Thanks Bob, I was thinking USB too, but I can do the car socket as well, As far as getting another battery monitor that may be in the future. They say you need to walk before you can ride a bike and being a newbie I think I am a just a little past the crawing stage!

**John in Santa Cruz** · 06-19-2019, 09:43 PM

normal USB is at most 10 watts, 5V at 2 amps (the original USB 1 spec was 0.5 amp, for 2.5 watts max). USB-C has a 'power' spec for much higher power levels, but this requires special power cords that are captive to the power supply as regular USB cables would melt down under that level of power.

a typically laptop needs somewhere from 50 to 90 watts to charge and operate. some very low power ones like 'ultrabooks' might be as low as 30 watts, but at 5V thats still 12 amps. way way more than a normal USB outlet can provide..

conventional laptops mostly use 19V supplies to charge their battery packs, so to run them even on 12V, you need a DC-DC supply that converts 12V (really 10-14.5V) to the 19V the laptop wants. I've used cigar-lighter style DC-DC supplies from PWR+ with good results on several brands of laptops (these supplies tend to be brand specific due to the different size power connectors used on different laptops).

**John in Santa Cruz** · 06-19-2019, 09:46 PM

Quote:

Originally Posted by cpaharley2008

Ronn,
You do realize your computers are 12v appliances and that you are converting 12v to 120v which the computers then change back to 12v for their operation? Very inefficient use of 12v. See if you can find 12v USB charging cords, then you can just plug them into one of your USB outlets and bypass the inverter. Your batteries will last you a lot longer and you will only need the inverter when using the convection appliance.

no, computers are NOT 12V appliances. Nowdays the actual CPU chips use very low voltages, like 1.3V, at very high currents, generated onboard from DC-DC point-of-load supplies. Desktop computers have power supplies that output 12V, 3.3V, and 5V to power various parts of the circuitry. The 12V they do use has to be tightly regulated, with a tolerance of maybe 11.5-12.5VDC, while a automotive/RV style 12V is typically 11-14.4V. As I said above, most laptops expect 19V input.

**rbryan4** · 06-19-2019, 09:58 PM

Quote:

Originally Posted by John in Santa Cruz

no, computers are NOT 12V appliances. Nowdays the actual CPU chips use very low voltages, like 1.3V, at very high currents, generated onboard from DC-DC point-of-load supplies. Desktop computers have power supplies that output 12V, 3.3V, and 5V to power various parts of the circuitry. The 12V they do use has to be tightly regulated, with a tolerance of maybe 11.5-12.5VDC, while a automotive/RV style 12V is typically 11-14.4V. As I said above, most laptops expect 19V input.

Thank you John for the post. And no, computers are not 12V appliances. Even my tiny 13" Dell Inspiron laptop w/ tiny power supply requires 19.5V input, and is a 45W supply.

Brian B-P · 06-19-2019, 11:09 PM

Quote:

Originally Posted by cpaharley2008

Brian, both my MacBook Pro and my Mac Air operate and charge off the Escape 12v batteries without issue, as does 2 iPhones without any problems. I do use the higher 2.6 voltage USB plug. As far as time to charge, I'm not concerned but eventually they reach 100%. IBM computers should not be much different.

The current Mac Air charges only from USB-C, and the iPhones run on 5V (over any generation of USB), not 12V. So the iPhones use an adapter, and the others may as well; there is no 12V cord offered by Apple for the current MacBook, (just power adapters for 120V AC to Magsafe and USB-C ports).

IBM hasn't made laptops for a long time (they sold that business to Lenovo), so I assume that you mean other PCs... Dell, HP, etc.

**John in Santa Cruz** · 06-19-2019, 11:23 PM

ok, made me google it, and i found a range of high power USB-C car chargers for macbook pros and other such devices, this one is good for 87 watts which will power a heavy duty modern USB-C laptop
https://www.amazon.com/dp/B07KKNL1K8

Brian B-P · 06-20-2019, 01:18 AM

Yes, USB-C can deliver a lot of power. Without the Power Delivery feature, it's at 5 V; the highest Power Delivery mode can provide 100 watts... as 5 amps at 20 volts. Since it's not 12 V - and definitely not the something-more-than-12 volts of a trailer battery - it is always the output of a converter.

**John in Santa Cruz** · 06-20-2019, 01:35 AM

Quote:

Originally Posted by Brian B-P

Yes, USB-C can deliver a lot of power. Without the Power Delivery feature, it's at 5 V; the highest Power Delivery mode can provide 100 watts... as 5 amps at 20 volts. Since it's not 12 V - and definitely not the something-more-than-12 volts of a trailer battery - it is always the output of a converter.

yeah, you can't just wire something to USB power, you need a USB chip to supply the mojo to tell it what you need, and turn your load on and convert/regulate the voltage when you are told you can.

most of my DC stuff thats loose, has PowerPole connectors. I have various pigtails, PP30 to cigar socket. PP30 to SAE. PP30 to 2 more PP30s

my solar panel has a PP30 on its cable. I have a 20 foot 14 gauge white zip cord pp30-pp30 extension cord. I installed a couple PP30 connectors fused for 30A each off the dual golf cart battery (12V 220AH) in my camp trailer, next to a dual 2A USB and extra 12V cigar socket. my 200W AC inverter has a PP30 pigtail on its DC input.

cpaharley2008 · 06-20-2019, 05:54 AM

Perhaps I should have stated DC vs 12v, but there are ways to use the on board battery system without converting it to AC and then back to DC.....

padlin · 06-20-2019, 07:04 AM

Thinking about Ronn's original post about power use. He states they used the 2 pc's for 10 hrs. The adapters feed 90 and 65 watts, so 155 watts for 10 hours, if they output the max wattage which they probably don't. 1550 watts / 12v = 130 amps, not including inverter overhead, if I'm doing this right his results with the batteries being down to 60% isn't surprising, although this doesn't jive with the 2.1A max load he saw.

Another thought. When checking the voltage, which is what the GoPower uses and converts to the % it shows, any load makes the voltage figure look lower then it really is, turn off the load and the number goes up to it's static level. On my trailer, if the batteries are say 12.6 v, and I kick on the inverter and start the toaster, the reading goes to something like 11.9. When the toaster finishes and I kill the inverter, the voltage goes back up to 12.6 +/-.

Jim Bennett · 06-20-2019, 07:10 AM

As does the OP, if you have dual batteries, solar charging and a 1500W inverter I see no issue with just using that to plug in your laptop to a 120V outlet in the trailer for it's usage, and have many times myself. There have only been a couple rare occasions where I did not fully charge the batteries on a rainy day and might be cautious then, but would be with a DC plug too.

Of course, if my laptop came supplied with a USB charger I would use that for sure.

Does anyone know the typical energy losses either way? What about the charging rate, it would sure seem to me to be lower on USB. Mind you, I use my laptop not all that often and try to limit it's use as there are so many other things to do.

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