USB Device charging

[Noah]

I decided to spin off a new thread from the dinette lighting thread, as I made a statenent that perhaps you should just plug into to your 110 outlet while at the dock or underway, if you have an inverter. Apparently at the dock is OK, but while underway...maybe not so good. 

Below is an interesting study by Maine Sail regarding the efficencies of charging laptops, tablets, phones, etc. via a dedicated USB plug or using the 110v charging brick through an inverter.  In a nutshell, my takeaway is; unless on shorepower, it is more efficient on your house battery bank to charge via a dedicated 12v USB plug than to use 110v brick with an inverter. Just make sure your USB plug delivers enough current (at least 2.1 amps) if you are running an iPad tablet, or laptop.
http://forums.sailboatowners.com/index.php?threads/ipad-charging-12v-vs-inverter.159821/
This article may already appear elsewhere on our forum, if so, sorry for any duplication.

[John Langford]

Hi Noah, I think you meant to say 2.1 amps rather than volts. USB chargers for smart phones and tablets all provide 5 volts at a variety of currents from 0.5 to 2.4 amps. Unfortunately the world of laptops is not so sane. Different laptop brands and models specify different voltage levels and need more than 2 amps to charge quickly. Unless a particular laptop offers a 12 volt charger as an accessory, it means that you have to provide its proprietary charger with120 volts AC via an inverter if you are the boat or in the car.

If you are converting a cigarette lighter to a USB charging port it is worth making sure that the port is providing at least 2 amps at each (if it has more than one) USB outlet. A lot provide less or don't meet the specs they advertise which will increase your charging time.

[Noah]

Yes, amps! Thx.  I will edit. I ran into the not enough amps issue with my Blue Sea dual USB socket. Which is rated for 2.1 (+/-) but it is "shared" across both sockets. So it works OK for 2 iPhones but slower if an iPhone and an iPad are charging at the same time. Blue Sea does make a "fast charge" model that outputs 4.8A but I was not aware of it at the time I installed mine and don't know if it has a compatible face plate fit for my Blue Sea 360 model A/C-D/C maine distribution panel.

[KWKloeber]

Two notes on below:

Someone (on here or maybe C30 forum recommended I NOT install dedicated USB ports -- due to changes in the works and compatibility new? smart USBs, smart charging, etc.  Instead to just use a USB plug-in on a 12v socket.  I have two such that are both max 2.1a per each dual USB socket (several reliable mfgrs are available on Amazon etc.) so the total available is 4.2a.  I suspect there's other USB insert sockets available that are *smart* and could supply, say, 3a to a tablet on one port and 1.2a to a phone (which will typically charge on 0.5a,) or 2.1 to each.

On my laptop I use an aftermarket (very slim) brick (more like a wafer  ) that uses AC or DC power sources -- it works so well and has a smaller footprint that I just keep a few (on retractable AC power cords) at different locations around the house where I might use the laptop.  The charge voltage is adjustable and had popular power tips to fit most laptop brands.  Mine are many years old and have a 1a USB port, and I see newer adapters have a 2.1a port.

-kk

Unfortunately the world of laptops is not so sane.  Different laptop brands and models specify different voltage levels and need more than 2 amps to charge quickly. Unless a particular laptop offers a 12 volt charger as an accessory, it means that you have to provide its proprietary charger with 120 volts AC via an inverter if you are the boat or in the car.

If you are converting a cigarette lighter to a USB charging port it is worth making sure that the port is providing at least 2 amps at each (if it has more than one) USB outlet. A lot provide less or don't meet the specs they advertise which will increase your charging time.

[Noah]

Allegedly, the Blue Sea Fast Charge dual USB uses "Smart Technology" whatever that means? However, I am very much out of my depth here...i use the technology, but don't claim to understand how it works!

[KWKloeber]

Below is an interesting study by Maine Sail regarding the efficencies of charging laptops, tablets, phones, etc. via a dedicated USB plug or using the 110v charging brick through an inverter.  In a nutshell, my takeaway is; unless on shorepower, it is more efficient on your house battery bank to charge via a dedicated 12v USB plug than to use 110v brick with an inverter.

It's more efficient using a USB port in ANY event, it's just that when on shore power you really don't care if using the inverter or converter w/a 120v device charger is more inefficient. 

Look at is this way (profs tell students that electricity is like water and voltage is like gravity.)   If you are standing on the side of a hill, 12 feet (volts) above the ground level and want to get down to 5 feet, climbing way up to 120 feet, jumping to another hill, only to slide down to 5 feet (passing right where you originally were) -- is a heck of a lot more inefficient than just sliding from 12 feet down to 5 feet to begin with.

[KWKloeber]

Ahh ha!  What Blue Sea means is that it *smartly* recognizes how many amps the device needs to charge and matches that.  Given that they all charge at 5 volts, a 2.1a port could overcurrent a small device and damage the device's battery or charging board.  The BS USBs are **supposed** to supply 2.2a to both ports, but (I don't believe) will provide more than 2.2 to either port.  Though, a good question to the BS tech guys!

kk

Allegedly, the Blue Sea Fast Charge dual USB uses "Smart Technology" whatever that means? However, I am very much out of my depth here...i use the technology, but don't claim to understand how it works!

[KWKloeber]

You're good to go if you want to install a BS 1045 fast charge USB -- it's a standard 1-1/8" dia. that fits where your "current USB" (uuuugh pun) fits.  There's two QC models, the round and one that fits a Contura switch panel.

kk

[mainesail]

You're good to go if you want to install a BS 1045 fast charge USB -- it's a standard 1-1/8" dia. that fits where your "current USB" (uuuugh pun) fits.  There's two QC models, the round and one that fits a Contura switch panel.

kk

While I commend Blue Sea for finally developing a "useful" dual USB charging port, Blue Sea PN 1045, which retails at about $35.00, I think a wiser and considerably less expensive idea is to simply use USB 12V socket insert-chargers. One of my favorites, and the most reliable I have used, has been the Scosche USBC242M http://a.co/gyXlRxY for about $12.99. It will deliver the full 2.4A to each of the two USB ports and charge an iPad or iPhone just as fast as your Apple wall wart will. I have been recomending them to customers since the old dual 2.1A model came out. I have yet to hear of a single failure and I suspect I have approx 60 of them out there in use just based on teh number of links I have sent to customers and ones I have ordered for installs.. Heck just between my wife and I and all our vehicles and the boat etc. we own about 10 of them.... Not a single failure and we regularly charge two iPads off one Scosche... The nice thing about USB insert-chargers is that yous till retain the 12V socket for other uses.

By using USB "insert chargers" when the USB protocol changes or Apple or Samsung etc. change current demand, like when they went from 1A to 2.1A to 2.4A etc., you simply swap out the USB insert for a few bucks. You can also find them for less money but the quality is often suspect.

[Roland Gendreau]

While we do use the 12 volt usb chargers for use when underway, I have been looking at the new 110volt outlets with the integral USB ports such as this one

http://www.leviton.com/OA_HTML/SectionDisplay.jsp?section=53874&minisite=10251

These would be great when we are motoring or on shore power.  Having USB ports at multiple 110 outlets would be handy also.

Has anyone used them?

[KWKloeber]

One of my favorites, and the most reliable I have used, has been the Scosche USBC242M http://a.co/gyXlRxY for about $12.99.

DOUBLE ditto on that charger.  It's the one I found to replace one that was advertised to provide 2x 2.4a, but was one of those "untruth in advertisings and the 2.4 was shared. 

It performs flawlessly in the van, but I wish that they had made a "locking" version, like the Marinco, etc., plugs and sockets.

[mainesail]

While we do use the 12 volt usb chargers for use when underway, I have been looking at the new 110volt outlets with the integral USB ports such as this one

http://www.leviton.com/OA_HTML/SectionDisplay.jsp?section=53874&minisite=10251

These would be great when we are motoring or on shore power.  Having USB ports at multiple 110 outlets would be handy also.

Has anyone used them?

We have a few at home and a bunch in the bunk house at the ski place for convenience and for the kid factor seeing as they kept losing the wall warts. The problem is these only charge at a max of 3.6A so charging two iPads for example is pretty slow compared to a USB charger that can do the full 2.4A for each port.. 

However, I don't see any reason to use them on a boat when you already have 12V power available.  These are also not yet proven to hold up in a damp environment, and I know standard GFCI's don't stand up for very long in the marine environment unless you go expensive hospital grade with plated wipes etc... For the price a simple USB 12V insert-charger is the best bang for the buck, most efficient and when, not if, the marine environment gets it you're only out $8.00 - $12.00. Even at my cost our Pass & Seymour's (hospital grade) were about $40.00 each...

Remember every time you convert from DC to AC then back to DC you create energy losses and inefficiencies, sometimes as much as 40% less efficient than staying direct DC. Your phones, tablets and computers are already DC as is your vessels DC system. The USB insert-chargers just step 12V DC down to 5V DC, quite efficient step down. Using the 120V outlets forces you to convert 12V DC to 120V AC then back to 5V DC again and this is horribly inefficient. It also leaves you with the potential to leave the inverter in stand-by, sucking DC energy, when you're not using it.....

It is far too frequent these days when I don't have to tell a customer his on-board tablets, laptops and phones are consuming more DC energy per day than his 12V refrigeration. Two tablets, two phones and at least one laptop are more the norm these days than you'd imagine, and many boaters, especially those with children, far exceed that. Heck on our boat we have three tablets, three phones and one laptop. If my daughter has home work her computer is also on-board. These devices alone can easily exceed our DC refrigeration in -Ah consumption, even when charging/running on straight DC. Start doing that with an inverter and the -Ah consumption increases rather dramatically..

[KWKloeber]

Roland,

Installed 6 of them on a J this year ONLY because that's what the owner wanted. To my knowledge they are working well but he's limited to using them on shore  power.  Be advised, though, that they carry a big footprint and don't fit well in a standard depth 2x3 work box, especially if one is chained on to another (two cables in the box.)  I'm not an NEC expert, but code may require the deep boxes that I used.

-kk

While we do use the 12 volt usb chargers for use when underway, I have been looking at the new 110volt outlets with the integral USB ports such as this one

http://www.leviton.com/OA_HTML/SectionDisplay.jsp?section=53874&minisite=10251

These would be great when we are motoring or on shore power.  Having USB ports at multiple 110 outlets would be handy also.

Has anyone used them?

[Breakin Away]

...Unfortunately the world of laptops is not so sane. Different laptop brands and models specify different voltage levels and need more than 2 amps to charge quickly. Unless a particular laptop offers a 12 volt charger as an accessory, it means that you have to provide its proprietary charger with120 volts AC via an inverter if you are the boat or in the car...

I'd encourage anyone to shop around for a pure DC charger that runs off of 12v instead of an inverter. Step-up chargers that provide 19-20vDC are easy to find with plugs to fit virtually any laptop. I have a Targus one with about 8 different tips for Dell, Lenovo, Asus, etc; a genuine HP/Compaq one that also works for an old MSI netbook, one from PWR that's designed to work with a newer Asus (with a smaller tip), and another one from PWR that works with an Acer tablet/laptop hybrid. The generic ones can be found on Amazon usually for under $15. So far, every one that I have has outlasted the laptop they were bought for.

It's worth the effort to have the more efficient charging of pure DC. I hate inverters with the passion of someone who has had one catch fire. My new boat came with a really nice pure sine wave inverter that someday I'll use to for the microwave while at anchor, but meanwhile it's much better to invest in 12v appliances on the boat and avoid inverter wherever possible. So much runs off of 12v these days anyway.