bsangs
E35-3 - New Jersey
Two of the three cigarette lighter style ones I have are wired into the cabin lights. (The third one is part of the AC/DC panel.)
USB PORTS ?
- Thread starter Ralph Hewitt
- Start date
I wired the cigar lighter to the panel circuit breaker with overkill #10 wire. Although a low-draw USB insert shares the outlet, I didn't want my WM 200- watt portable inverter to overstress small wires.
I use the cigar plug outlet/inverter for a small one-cup Keurig coffee maker, and to power a laptop.
I use the cigar plug outlet/inverter for a small one-cup Keurig coffee maker, and to power a laptop.
Alan Gomes
Sustaining Partner
One thing to keep in mind with these things is that they may have EMI/RFI from Hades--particularly the cheap Chinese stuff. Same goes for LEDs. That could be an issue on your VHF and other radio equipment. Check that out before you go to the trouble of mounting it permanently.
I went with a BlueSea model. Note the mention of internal filtering for reduced EMI. There's a reason it costs a bit more.
I went with a BlueSea model. Note the mention of internal filtering for reduced EMI. There's a reason it costs a bit more.
Yes, LEDs with dimmers are especially problematic. A 470uF electrolytic capacitor across the supply helps significantly.
FWIW I installed these lamps with a USB port built in, really like them.
Prairie Schooner
Jeff & Donna, E35-3 purchased 7/21
Thanks Christian. Wire gauge is something that hadn't occurred to me. Most everything I'm planning to use has standard power needs. The only thing I'm not sure of is my CPAP power supply which plugs into a cigar lighter. These are the specs on it:
Input: DC 12V-24V~12A Max . . . . Output: 24V 3.75A 90W
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I used it on our recent cruise with a 12v extension cord from the V-berth to a cigar lighter socket the P.O. patched into the stereo circuit. It seemed to work okay. I put the machine on airplane mode and turn off the water heater and tube heater functions.
We have a cigar lighter socket in the galley trash bin access cubby. I don't know if that's standard. I haven't paid attention to it's wire gauge or tried anything in it yet. And I don't know what circuit it's on. We don't have plans for a plug-in inverter or any 12v kitchen appliances at this point. But we should probably plan for that.
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Prairie Schooner
Jeff & Donna, E35-3 purchased 7/21
Thanks Alan. This is an important consideration I don't know enough to have thought of. I'm planning on putting one of the units right next to the VHF radio in the nav station. The single head unit you linked is about $40 so that makes this look like a pretty good deal. I kind of wanted the volt meter function to augment the original analog meter in our electric panel. The caps would be an unnecessary hassle, but they don't seem to make an interior version. You can't always get what you want.
Do you think the cheaper import unit mounted in the V-berth would be as likely to cause interference? Does the interference come from proximity or just being part of the/a circuit?
Prairie Schooner
Jeff & Donna, E35-3 purchased 7/21
Thanks 'shard'. We got LED replacement bulb/panels which plug into both kinds of original light fixtures. I don't have the company name at hand. I don't know enough to tell if they have the capacitor and haven't checked whether they cause any EMI (not sure how to). We're not inclined to spring for replacing fixtures but this does look like a good solution.
Alan Gomes
Sustaining Partner
Here ya go: http://wiresizecalculator.net/wiresizechart.htm
So, for 90W at 12v that would be a 7.5A draw. If you wired it with #14, which matches most of the other wiring in our boats, then you will be just fine. But note that with your CPAP heater off, you are not going to draw anywhere near that 90W in the first place. It's the heater that's the real amp sucker. The CPAP itself draws very little. I use one on my boat with the heater off as well and I see almost no drop in my batteries the next day.
FWIW, I leave the heater off even when I use it at home, as a matter of personal preference. I have run it on the boat overnight just to test it, since my wife uses CPAP and relies on the humidifier. It works just fine, though my batteries definitely take a hit by the next morning, If the next day is sunny then my solar panel can put it right.
If you have a long wire run then you might want to go with AWG 12 or even 10, since it doesn't hurt anything (other than your wallet, slightly) and will reduce the voltage drop at the other end. But if you are not running the humidifier then you should be fine either way.
Alan Gomes
Sustaining Partner
This is hard to say. The wiring in the boat can act as an antenna and propagate the interference. The only way you could know is to try it. That's why I suggested that if you want to go that route, wire it up but do not drill any holes. Amazon has easy returns so you're good there.
When you test your VHF, just find a clear channel and drop the squelch so you can hear the background noise. See if it changes when you switch it off or on. Test it also with other radios you might have on board, such as your handheld VHF, if you've got one.
My own preference would be to go with the Blue Sea, cry once, and have some confidence that it will be good right from the start. Given what we spend on our boats the $78 isn't much. But full disclosure: I also have the same Blue Sea meter shown in that picture, mounted as a stand-alone unit, and the first one croaked on me after a few years. No idea why. I replaced it with an identical one and so far it's been fine.
Saverio
Member III
I have these too
Prairie Schooner
Jeff & Donna, E35-3 purchased 7/21
Your replies are very helpful, Alan. Thanks much!! It's especially useful to have input from someone who is also using a CPAP.
I ordered one of the Blue Seas units for the nav station. A quick search online found that they were going for as much as $105 elsewhere. I'll also set up wires for the V-berth and order one of the import models. If it causes problems there I'll send it back. We do have a handheld VHF as well as the full-bird radio.
Sounds like a good plan.
For RF energy that might interfere with VHF and nav, adding a snap-on ferrite core to the supply leads (as close as possible to the noise source) will help to limit conducted emissions.
Prairie Schooner
Jeff & Donna, E35-3 purchased 7/21
This is great. If you guys keep helping me like this, in a few more years I'll be able to apply for my associates degree in Electrical Engineering. Which is the supply lead?
LOL, glad to help with your continuing education! Just clip it around both the +12v and black lead supplying power to it (preferably within a few inches).
Of course, now that we've all installed these things, the world standard has switched to USB-C. 
FWIW, I plugged the current iPad into a cigar-lighter outlet, and it wouldn't charge.
When I re-wired Arcturus, I put in a dedicated breaker for the 12V outlets, and sufficient wiring to support them. Had a halogen spotlight at the time, for the cockpit, that drew quite a lot of power. (And blinded me with reflections off the rigging, every time I tried to use it. (It would blow a fuse every time I tried to use it from my ATV on the farm.))
The outlets on Wild (and many other things) seem to be scabbed on to the "stereo" circuit. This is bad. The biggest draw there is the Dometic AC/DC freezer, but it no longer seems to work on DC...
FWIW, I plugged the current iPad into a cigar-lighter outlet, and it wouldn't charge.
When I re-wired Arcturus, I put in a dedicated breaker for the 12V outlets, and sufficient wiring to support them. Had a halogen spotlight at the time, for the cockpit, that drew quite a lot of power. (And blinded me with reflections off the rigging, every time I tried to use it. (It would blow a fuse every time I tried to use it from my ATV on the farm.))
The outlets on Wild (and many other things) seem to be scabbed on to the "stereo" circuit. This is bad. The biggest draw there is the Dometic AC/DC freezer, but it no longer seems to work on DC...