120 volts to 12 volt

Exoset

Member
Oct 3, 2018
58
CANADA, QC
Boat Info
2014 Sea Ray 310 Sundancer
2017 RAM 3500 Dually Mega Cab Limited Cummins 6.7 Aisin
Engines
5.7 350 Mag DTS w/Bravo III Axius Drives
Hey guys,

I find myself stuck in a field completely unknown to me... electricity.

Here is the context :

I have a SeaRay 310 DA 2014 with 2 circuit 12v and 120v (My knowledge pretty much stops here...)

I want to plug a router on the 12 volts circuit because I want it up all the time and not only when I am at the dock. Here are the specs :

Input voltage : Universal 100 to 240 VAC
Frequency : 50-60 Hz
Input current : PoE not enabled: 0.82A maximum
**PoE enabled : 1.55A Maximum (I WILL NEVER HAVE POE ENABLED)
Surge current : 90 A peak and less than 8 Arms per half cycle

I was wondering how I could plug this in order to use the 12 volt circuit, 0.82A seems not to be a big number compared to other devices in the boat, but then again I am no expert.

Does the idea sounds crazy, do I need some specific stuff or do you think it is safe to plug it directly on the 12 volts (UPS ?)

Thanks
 
I would be surprised if it uses 100 watts (.89 amps x 120 volts). My cockpit fridge listed 30 watts, which seems low... should be no big deal at all, imo.

most electronics use an adapter/transformer and take the voltage down to 5-19 volts depending. Not sure what your router has, but either way, should be good.
 
Last edited:
Here is what I was able to find :



It says : 12V (3.5A)

Since it is 12 Volt, I understand I am ok ?
Assuming the is the name plate for the wall wart for the router... What that says is you can run 12VDC straight to the router. You will have to purchase the correct plug/wire or cut it off the wall wart.

What you link to would work for running the wall wart off of 12V.
 
BTW, thank you Ididntdoit, Chris and Jim. I wasn't feeling safe to do something I don't really understand.
 
What the guys above are saying is that you don't need an inverter. You don't really need anything. You could wire that router directly to a 12V source (with a fuse and a switch, of course). You'd basically cut off the transformer side of the existing power plug.

If you want the easiest possible wiring you should buy a male cigarette lighter extension (you linked a female) and wire it directly to the router. Plug it in when you want it on, unplug it when you don't....
 
I would avoid doing any DIY electrical work and just buy the inverter and be done.

It will come in handy for a multitude of stuff throughout the years.

The 300W unit linked above for $30 is a good deal..... I like it had a fan built in.

When I'm on my laptop watching movies on the hook my old inverter would heat up really fast.
 
Where do you want to place the router? Is there a cigarette lighter nearby that you can connect to - or would you have to run a 12v feed to that spot (which presuming you would not do on your own)
 
Unfortunately I don't have any cigarette lighter near so I will have to go from the 12 volt on the radio, to a female adapter, to a male, directly to the router or through a small inverter, I am not sure yet.

What I like with the inverter is the ability to have a regulated output to the router, no surge or else... Am I right to assume this is safer ?
 
The inverters are about 85% efficient, so you will be wasting power. Its not a lot

I would wire it direct, the inverter will not regulate the power, it will take the Direct current 12 volts, or 13 volts and convert it to AC at the ratio its 11 volts it will be lower, if its 13 volts, it will be higher...

You could get rid of the transformer, and the inverter and get one that matches the plug on the router to a 12 v aux (cig lighter)

but any which way will work that was discussed in the above posts, and its personal preference which is better.

Is it 6? or a half dozen?
 
What model router do you have?

Considering you're already planning on wiring in a cigarette lighter to the radio -- you really should look at just wiring in a DC power plug that will connect directly to the router (as Chris-380 has suggested). It gives you the 'always on' while only consuming power that is needed - no loss of efficiency due to the inverter process ( 12vdc > 120vac > 12vdc ). The finished install is also cleaner (no cig lighter, no inverter).

Depending on the inverter make/model, I've had a few in my car that don't like the engine starting due to the sudden drop in 12v. A lower quality unit may 'beep' and drop the output momentarily, causing your router to reboot during engine start. If you have a house battery bank, or if the battery charger is on while cranking - either of these may help alleviate that issue. Perhaps others can share their experience on inverters and their use during engine starting so you can get a known working model.

Example of a DC power plug. You would need to validate the diameter of the plug for your model router and order the proper size.
https://www.amazon.com/ACL-Feet-Mal...=B074TGH915&psc=1&refRID=Z4MWZZN7F8NN1YCMF5S3

Couple of considerations:
- Replacement cost of the router, should it get damaged along the way if you hard wire it in using a 12v DC power plug.
- Fully functional battery charger while at the dock (ensuring you don't eventually drain your 12v batteries) - either due to (a) the inverter running all the time, or (b) the small DC current being consumed constantly by the router.
 
Model router is a Cisco ISR C1111-8PWA, the plug is kind of special, it is a 4 pins plug like this (but not this one) :

iu


I am not even sure I can find one, I will have to order a complete power supply kit from Cisco. Which is why I wanted to plug it in an inverter, to avoid cutting the power supply but I understand there is a risk when cranking.

I was thinking it was not an issue since batteries for the engine are not the same than those used to live aboard, but a 12 volt directly to the router seems to be the best way to do this (with a 3-4 amp fuse), the router already have a switch so I don't think I will need to add another one.

Fortunately, I asked before doing anything stupid :p.

Thanks again guys.
 
Last edited:
Model router is a Cisco ISR C1111-8PWA, the plug is kind of special, it is a 4 pins plug like this (but not this one) :

iu


I am not even sure I can find one, I will have to order a complete power supply kit from Cisco. Which is why I wanted to plug it in an inverter, to avoid cutting the power supply but I understand there is a risk when cranking.

I was thinking it was not an issue since batteries for the engine are not the same than the one used to live aboard but a 12 volt directly to the router seems to be the best way to do this (with a 3-4 amp fuse), the router have a switch so I don't think I will need a switch.

Fortunately, I asked before doing anything stupid :p.

Thanks again guys.
That was my fear.... 4 pin plug. Two pins for the 12VDC and 2 pins for the PoE power. At this point I would recommend that you go with the inverter.
 
I will shut the POE in the switch and won't use it, it shouldn't draw any power from the 2 POE pins then, what do you think ?
 
I will shut the POE in the switch and won't use it, it shouldn't draw any power from the 2 POE pins then, what do you think ?
That's correct disable PoE in the router, plus not having any PoE devices plugged in to the router will eliminate any additional current draw.
 

Attachments

  • miniATX.PNG
    miniATX.PNG
    128.5 KB · Views: 154

Forum statistics

Threads
112,950
Messages
1,422,861
Members
60,932
Latest member
juliediane
Back
Top