Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Charging multiple high power USB devices without cigarette lighter

  1. #1
    Newbie
    Join Date
    Aug 2011
    Posts
    5

    Charging multiple high power USB devices without cigarette lighter

    Wow! Just found the forum and am likely to get sidetracked from my original project. Lots of cool stuff to do.

    Ok, the project that got me here is as follows:
    I am sick of the multiple chargers for the iPad, iPhone, blackberry, Bluetooth, etc in my truck. I have decided to bypass the cigarette lighters and replace them with the waterproof USB panel jacks from l-com with retractable cables for each device.

    The problem I need help with is what to use for the12v-5v dc dc conversion. I have the fuse block and want to direct wire the jacks in. I am looking to add 4 ports that are all 10-15 watt capable.

    I have no problem in doing the wiring but am looking for suggestions in the following specific areas:
    1) is there a single component that can source that much power? If so, ok to run these in parallel?
    2) am I better off with multiple components (prefer less than 1:1)?
    3) any suggestions on parts to consider using?
    4) any other considerations?
    5) any links to others that have done this? I can't be the first.


    Thanks for any help you can provide!

  2. #2
    FLAC SNOtwistR's Avatar
    Join Date
    Nov 2009
    Location
    Keswick,On Canada
    Posts
    1,546
    this might be a good solution for you, rugged and simple to wire up SNO http://store.mp3car.com/DC_Powered_4..._p/adt-015.htm
    Last edited by SNOtwistR; 08-21-2011 at 04:42 PM.

  3. #3
    Newbie
    Join Date
    Aug 2011
    Posts
    5
    Was looking at the opus dcl11 but it would not cover all the ports I want with one device. I could use 2 or 3 of these. Not too concerned with power draw as this is coming off of my aux battery which is deep cycle agm. There has got to be an easier way.

  4. #4
    Raw Wave
    Join Date
    Nov 2009
    Posts
    2,119
    IMO all you need is any 3A or higher 5V converter. It could even be linear (~30% efficient with 30W of heat from ~14V @ 3A), though with the price of typical dc-dc converters (!90% efficient) I'd avoid linear.

    Someone on mp3car did have an (IMO) great 5A or 10A 5V converter for a reasonable price.
    Otherwise there are various commonly available 2A 5V converters.


    But I'd recommend some form of cut-out - even deep cycles do not like being flattened. (Most recommend not discharging more than 50%; that typically increases deep-cycle battery-life 3-fold compared to 80% discharge.)
    The ~$25 MW728 could be used - even with an extra relay to disconnect its sense circuit after its normal low-voltage load-disconnect (in that case with a manual-on push-button to re-activate it).

  5. #5
    Constant Bitrate
    Join Date
    Jun 2010
    Location
    Vancouver, Washington, United States
    Posts
    221
    PaulF recommended me a good one (5v 10A converter) but I don't recall what it was off-hand... I'll find the info for it and edit this post when I do.

    I recommend hooking it up on an accessory line so it can't kill the battery without the keys in the ignition.

  6. #6
    Newbie
    Join Date
    Aug 2011
    Posts
    5
    Looking at one by calex that supplies 30a. More than I will ever need but if I mount it under the hood from my aux fuse panel I can run a 5v rail inside the cab and then I will have a fused 5v panel next to my fused 12v panel.

    Summary of the system:
    12v from alternator to hellroaring battery isolator
    To exide 100ah agm starting / deep cycle battery
    To blue sea 12 position ATC fuse panel
    30a leg from fuse panel using 10 ga to inside of cab to blue sea 6 position 12v panel
    30a leg from 12v fuse panel under hood to calex dc dc converter also under hood
    10 ga from calex to cab mounted blue sea 5v fuse panel
    14ga leg from 5v fuse panel to each of 4 panel mounted l-com waterproof USB jacks, fused at 2a each.
    14 ga leg to window mount gps
    Calex has a leg to shut it off when shunted to grd
    Calex will also auto shut down at 9.something v, too low.
    Will probably switch the feed to calex to be able to park for extended periods of time without killing aux battery.

    Lots of info there. Can post fills and part numbers and cut sheets if requested.
    All above under the hood.

  7. #7
    Raw Wave
    Join Date
    Nov 2009
    Posts
    2,119
    The latter can be overcome with a timer that disconnects after a preset period. I'd suggest it disconnects itself too (especially if it's a 555 circuit - they take 10mA) - it could break the "feedback" connection in the latching SPST relay I described in Powering carpc with SPDT relay. (The IGN or ACC could parallel or replace the ON switch's +12V pulse that turns it on, noting that that relay is on whenever the ON switch leg remains +12V.)


    Or a low-voltage disconnect. Maybe the MW-728 I often mention, and in conjunction with that latching circuit above....

  8. #8
    Newbie
    Join Date
    Aug 2011
    Posts
    5
    Here is the Calex converter link. http://www.calex.com/pdf/HCM.pdf Talked to the engineers and it seems to be fairly bullet proof. Sells for about $165, steep but should never need another 5V supply again.

  9. #9
    Raw Wave
    Join Date
    Nov 2009
    Posts
    2,119
    I'd search for that mp3car 10A USB supply (which may be what Ryven referred to).

    My view is that it doesn't matter how bullet proof it is, one day it will fail.
    That's why I consider redundancy - ie, have access to a spare.
    And I'd probably buy 2 cheaper units up front than a single $165 device. (I wouldn't invest and extra $165 "just in case" - unless it really was IMO critical. But then I'd probably have TWO spares!)


    PS... 25Aug11 05:55 UCT: I searched this morning but couldn't find the 5V PSU I was thinking of. I'm sure is was built by an mp3car member. As I recall, I was impressed by its price and specs etc.
    But the MeanWell unit that Ryven Found in the next reply seems good. (Not that I have used MeanWell, but my readings suggest they are good & reliable. Certainly IMO a great price!)
    Last edited by OldSpark; 08-25-2011 at 12:03 AM. Reason: PS...

  10. #10
    Constant Bitrate
    Join Date
    Jun 2010
    Location
    Vancouver, Washington, United States
    Posts
    221
    Found it!


    This is what PaulF recommended for me & I picked up 2. The price is good and the efficiency and especially power output for a 12v input are difficult to beat.

Page 1 of 2 12 LastLast

Similar Threads

  1. Cigarette Lighter Power Adapter for Monitors
    By HiJackZX1 in forum MP3Car Products - store.mp3car.com
    Replies: 7
    Last Post: 04-08-2011, 05:34 PM
  2. Question about Cigarette Lighter for power.
    By ninvertigo in forum General Hardware Discussion
    Replies: 8
    Last Post: 09-18-2007, 08:51 PM
  3. Can a P4 e-PC be powered by a cigarette lighter power?
    By BlackAWD in forum Power Supplies
    Replies: 5
    Last Post: 10-04-2005, 03:54 AM
  4. laptop & lilliput power from cigarette lighter?
    By doctordl in forum General Hardware Discussion
    Replies: 1
    Last Post: 04-12-2005, 08:41 AM
  5. Cigarette Lighter / Power
    By leesilk in forum Power Supplies
    Replies: 3
    Last Post: 05-27-2003, 07:39 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •