Charging portable devices - SailNet Community
 
LinkBack Thread Tools
post #1 of 9 Old 06-15-2012 Thread Starter
Senior Member
 
Join Date: Jul 2007
Location: Philadelphia
Posts: 989
Thanks: 0
Thanked 10 Times in 10 Posts
Rep Power: 9
 
Charging portable devices

An observation on charging portable devices; vhf, camera, computer,.. with cigarette lighter socket and small plug in 110v converter, device cigarette lighter charger cord, usb cigarette lighter cord and 110v usb charger plugged into plug in 110v charger.

So what I have for electric power ;
Single 12v wet cell battery, small 16"x18" solar panel and alternator on 6hp outboard.

I have always had sufficient charge when needed, and even over winter on the hard the small solar panel is enough to keep the battery charged for cabin lights and FM radio.

So the question;
Why does everything charge faster when using the 110v cigarette lighter plug in charger than when using the device charger cord or usb charger cord directly from the cigarette lighter?

1970 Havsfidra 20 by Fisksatra
On the Delaware River at Fox Grove Marina Essington PA
Ulladh is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 9 Old 06-15-2012
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,854
Thanks: 0
Thanked 11 Times in 9 Posts
Rep Power: 11
   
Re: Charging portable devices

Most 12VDC charging devices are meant to work from automobile cigarette lighters where the voltage is usually 14.0 or above when the car is running.

Your small storage battery, when not itself on charge, has a voltage somewhere around 12.4-12.6, so the 12VDC devices are being powered by less voltage than they're designed for.

When you use the 120VAC inverter, you essentially get around this "limitation".

Bill
btrayfors is offline  
Quote Quick Reply Share with Facebook
post #3 of 9 Old 06-15-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,549
Thanks: 6
Thanked 137 Times in 134 Posts
Rep Power: 11
   
Re: Charging portable devices

Not necessarily, Bill. A USB "car" adapter cuts the voltage down to 5 volts, so whether it is starting with 12.2 or 14.4 doesn't matter.

OTOH every "USB" charger has a maximum output power. Many of them are only 500mA, the USB standard. Some are as low as 150mA to recharge earmics, etc. And the ones designed for more powerful smartphones are often rated 1000mA or higher. I've got a car (ciggy) adapter rated for 2A with two USB sockets in it, it can provide up to 2A to whatever is plugged in, whether that is split or sent to just one device.

I would bet that Ulladh is just seeing the difference between the capacity of the different chargers he has, and that 110-vs-12 is no part of it.

And I'll note that these days, the rated capacity of chargers is being printed in ever tinier type on the labels, often it needs both reading glasses AND a magnifier to make it out.
hellosailor is offline  
Quote Quick Reply Share with Facebook
post #4 of 9 Old 06-15-2012
Senior Member
 
Join Date: Aug 2006
Location: Arlington, VA
Posts: 1,854
Thanks: 0
Thanked 11 Times in 9 Posts
Rep Power: 11
   
Re: Charging portable devices

Quote:
Originally Posted by hellosailor View Post
Not necessarily, Bill. A USB "car" adapter cuts the voltage down to 5 volts, so whether it is starting with 12.2 or 14.4 doesn't matter.

OTOH every "USB" charger has a maximum output power. Many of them are only 500mA, the USB standard. Some are as low as 150mA to recharge earmics, etc. And the ones designed for more powerful smartphones are often rated 1000mA or higher. I've got a car (ciggy) adapter rated for 2A with two USB sockets in it, it can provide up to 2A to whatever is plugged in, whether that is split or sent to just one device.

I would bet that Ulladh is just seeing the difference between the capacity of the different chargers he has, and that 110-vs-12 is no part of it.

And I'll note that these days, the rated capacity of chargers is being printed in ever tinier type on the labels, often it needs both reading glasses AND a magnifier to make it out.
Yeah, you could be right. But, maybe not.

I have a 120VAC to USB adapter which is rated at 500ma, while its 12VDC cigarette lighter equivalent is rated at 700ma (and 12-24 VDC). Go figure!

Guess the best answer is: It is what it is. Live with it!

Bill

Last edited by btrayfors; 06-15-2012 at 08:04 PM.
btrayfors is offline  
Quote Quick Reply Share with Facebook
post #5 of 9 Old 06-15-2012
Senior Member
 
asdf38's Avatar
 
Join Date: Jul 2010
Posts: 778
Thanks: 1
Thanked 12 Times in 11 Posts
Rep Power: 6
 
Re: Charging portable devices

Quote:
Originally Posted by hellosailor View Post
Not necessarily, Bill. A USB "car" adapter cuts the voltage down to 5 volts, so whether it is starting with 12.2 or 14.4 doesn't matter.

OTOH every "USB" charger has a maximum output power. Many of them are only 500mA, the USB standard. Some are as low as 150mA to recharge earmics, etc. And the ones designed for more powerful smartphones are often rated 1000mA or higher. I've got a car (ciggy) adapter rated for 2A with two USB sockets in it, it can provide up to 2A to whatever is plugged in, whether that is split or sent to just one device.

I would bet that Ulladh is just seeing the difference between the capacity of the different chargers he has, and that 110-vs-12 is no part of it.

And I'll note that these days, the rated capacity of chargers is being printed in ever tinier type on the labels, often it needs both reading glasses AND a magnifier to make it out.
Yeah I second this completely. There is no general reason why the 12V chargers would take longer. Even if the 12V droops to 11V the charger is outputting 5V and won't be affected. I think it's either perception or the particulars of the chargers you're using.
asdf38 is offline  
Quote Quick Reply Share with Facebook
post #6 of 9 Old 06-15-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,549
Thanks: 6
Thanked 137 Times in 134 Posts
Rep Power: 11
   
Re: Charging portable devices

Without underestimating the ingenuity of the "yes yes, make cheap" crowd, most of the USB car adapters now use dc-to-dc converter chips which might need two volts of overhead (i.e. 7 volts from the electric system) and IIRC there are many that only need 6v. Ain't technology grand. And of course, even the AC "wall warts" have mainly stopped using transformers, because metal is so damned expensive and chips have become so cheap.

What I can't figure out is how the hell they still make a profit, after shipping this stuff halfway around the world with fossil fuels. Color me baffled.
hellosailor is offline  
Quote Quick Reply Share with Facebook
post #7 of 9 Old 06-16-2012
Superior Sailor
 
Squidd's Avatar
 
Join Date: Sep 2011
Location: Eagle River Wi.
Posts: 978
Thanks: 6
Thanked 9 Times in 8 Posts
Rep Power: 4
 
Re: Charging portable devices

Quote:
Originally Posted by hellosailor View Post
What I can't figure out is how the hell they still make a profit, after shipping this stuff halfway around the world with fossil fuels. Color me baffled.
Government subsidies that allow flooding the market with unrealisticly cheap goods, creating a monopoly, dominating the market (ie the world) and then wammo up the wazoo and we all end up speaking Chinese...

"Might as well take 'er out...If anything is gonna happen...It's gonna happen out there..."
"Captin Ron"
Squidd is offline  
Quote Quick Reply Share with Facebook
post #8 of 9 Old 06-16-2012 Thread Starter
Senior Member
 
Join Date: Jul 2007
Location: Philadelphia
Posts: 989
Thanks: 0
Thanked 10 Times in 10 Posts
Rep Power: 9
 
Re: Charging portable devices

Thanks for all the responses.
I was thinking it had something to do with the plug in 110/120v converter making more amps available for the other devices, but I just don't know enough about electrical systems.
I only charge one device at a time and only charge the computer when the outboard is on.
There are to many variables within all these small sealed black boxes to really know what is going on.

1970 Havsfidra 20 by Fisksatra
On the Delaware River at Fox Grove Marina Essington PA
Ulladh is offline  
Quote Quick Reply Share with Facebook
post #9 of 9 Old 06-16-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,549
Thanks: 6
Thanked 137 Times in 134 Posts
Rep Power: 11
   
Re: Charging portable devices

"There are to many variables within all these small sealed black boxes to really know what is going on. "
Not really. Input and output are always on the label, and very little else matters as there is always enough overhead (extra amperage/voltage) for these devices to function as intended. I'm betting that if you can magnify the labels enough to read them, you'll find the devices with the highest output amperage rating (mA) are the ones that charge fastest.
hellosailor is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Signaling Devices QuickMick Gear & Maintenance 12 10-02-2010 07:36 PM
FLIR devices.. groundhog Gear & Maintenance 5 01-11-2008 05:05 AM
Multiple Charging Devices Tom Wood Gear and Maintenance Articles 0 02-01-2001 07:00 PM
Kenyon Navagation devices duke Gear & Maintenance 1 11-02-2000 03:33 PM
Marine Sanitation Devices Kathy Barron Cruising Articles 0 09-10-2000 08:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome