Sign in to follow this  
Followers 0
pinkflydxx

12v Power while on Shore Power

10 posts in this topic

I installed a 12v power supply (i.e. dual cigarette lighter style) by jumping off of the wiring going to my cabin lights over the dinette area.  One of the dual plugs is a cigarette lighter style and the other is a dual USB plug - for charging cell phones, etc.  When I am using the cabin battery (not on shore power), both plugs operate perfectly (cigarette lighter side and dual USB plugs).  However, whenever I am plugged into shore power, the dual USB plugs will not work properly - i.e. they will not charge the cell phones.  All the 12v lights work as they should and as best I can tell the 12v cigarette lighter side of the plug seems to work properly.  As soon as shore power is disconnected, the dual 12v USB plugs work fine and cell phones charge properly.

 

Any ideas on what is going on with this?    Currently my solution is that, when on shore power, I will charge the phones by using the 120v plugs - and when traveling or boondocking use the 12v plugs.  Not a major inconvenience, but curious as to why this may be occurring.  Thanks.

Share this post


Link to post
Share on other sites

not a clue really, except to say, have you tried a "test" in another vehicle ?,  if both devices work, ( charges your cell phone, etc.) then you may have a defective device. if you would test the device, in say your automobile, ( no shore power) and all works, then could be just a defective charger unit. i am no expert, but shore power is just for ac power, all 12v power should be derived from on board 12v batteries, someone with superior knowledge may correct me if i am wrong. don't know if this is any help. good luck , joe from dover.

Share this post


Link to post
Share on other sites

The USB adapter worked fine in other vehicles and works fine in RV as long as not on shore power.  It is odd because the USB insert/adapter has a light on it to indicate that it has power and that light stays on whether on battery or shore power.  It just will not charge the cell phones when on shore power.  I am at a loss on this one since all other 12v items (lights, etc) work fine. 

I was wondering if the shore power somehow connects to the 12v system in order to charge it when plugged into shore power - and in doing so it somehow alters the 12v power supply that causes the USB item to not work at that point - perhaps changing or altering the polarity / Hz / signal waveform / etc.  As I said everything else works fine on either battery or shore power - other than the USB's capability to charge the cell phones when on shore power.

Edited by pinkflydxx

Share this post


Link to post
Share on other sites

there are discussions relating to your question about shore power and how it interacts with the 12v on board batteries. you may have to go back through the posts to find the specific thread (s) i am referring to. hope you can find the info, i know it is here somewhere.joe from dover.

Share this post


Link to post
Share on other sites

It maybe over voltage of the USB ports, the USB out put is only 5 volts and reasonably accurate as far as regulation so on the charger voltage it maybe too high for the USB regulator to deal with so it shuts down to avoid over charging the phone etc. Lithium ion battery are very fussy about accurate charging and have a tendency to catch fire if over charged.

Share this post


Link to post
Share on other sites

As Maineah said you might have an over voltage scenario, Also if you have an old style 6300 converter you might have a considerable amount of AC voltage mixed with the DC. The old 6300 converters are only half wave rectified and not full wave rectified. If you have a multi meter set it to AC and test your 12vdc circuit while plugged into shore power. If you do have AC mixed with the DC the bad news is AC will fry some 12vdc devices. Only cure is to upgrade your converter to a modern one. One other problem with the old 6300's is over charging of the coach battery when on shore power for long periods of time. The old 6300 converters have a relay that switches out the coach battery from the coaches 12vdc circuit and supplies the 12vdc circuit with it's 12vdc half wave rectified power supply. When the relay is switched when plugged into shore power the battery is connected to the converters charger. If you don't already have a multi meter consider purchasing one, they are worth their weight in gold! 

Share this post


Link to post
Share on other sites

great info -- makes me curious about my converter. any help with determining if my 92 winnie has a "6300" converter? joe from dover

Share this post


Link to post
Share on other sites
1 hour ago, hunkaman said:

great info -- makes me curious about my converter. any help with determining if my 92 winnie has a "6300" converter? joe from dover

I believe it is a "switching " supply, old tech but better than the old ones but that does not mean it can not have an issue. As Greg said a volt meter is in order. This is not to say you do not have some thing wrong with you USB device but you got to start some where and it does work on battery power so the charger is kind of suspect. .

Share this post


Link to post
Share on other sites

I have upgraded my last two toys with the 6345u's http://www.parallaxpower.com/6345ru-replacement-upgrade-6345ru they are a solid state device outputting clean DC.
Also for emergency 12vdc power for my ham station I have an IOATA converter float charging full time a group 27 agm, Both the IOATA and 6345 connect the battery and 12v output circuit in parallel. Both have some sort of smart charger, the battery in parallel itself acts as a filter. The IOATA I have is rated at 55 amps and I think the 6345u is 45 amps.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0