Fuse for Auxillary Electrical Circuit?

Mar 23, 2015
259
Catalina 22 MK-II Dillon, CO
Hi Guys,
I have a Catalina 22 that has two "cigarette" outlets run to my distribution switch panel. I need the switch for another purpose but want to keep the receptacles to charge my phone and who know what else. I'm going to re-wire directly to the battery and it seems to me that an inline fuse would be in order, yes? Any suggestions as to a reasonable fuse size?
cec
 
May 27, 2004
2,057
Hunter 30_74-83 Ponce Inlet FL
The switch protected the circuit, not the connected device. So be aware that you should check the requirements of the device(s) to select the proper amperage fuse to install.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,505
CAL 35 Cruiser #21 moored EVERETT WA
If you going to to make an electrical change, are you satisfied with patching it or are you ready to alter and upgrade the system to meet your needs. It is easy to install a 5 amp inline fuse. Are you ready to draw down your battery?
 
Jan 11, 2014
13,113
Sabre 362 113 Fair Haven, NY
The short answer is yes, you can wire directly to the battery.

The long answer involves more. Any circuit coming off the battery should be fused within 7 inches of the battery. The battery post should have no more than 4 connections on the post. For your application, a small sailboat with minimal electrical demands, a Blue Sea Fuse Block would make for a simple neat connection at the battery for up to 4 circuits.
 
Jan 4, 2013
287
Catalina 270 Rochester, NY
I agree with everything dlochner just posted. For a reasonable fuse size I would suggest 5 to 7 amp fuse for things like cell phones. You can always go larger up to the wire capacity.
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
What is the "other" thing you want to wire in? I added a cig lighter socket to power my laptop and charge phones. The socket is so seldpm used as a phone charger that I added the socket to my cabin lights/fans breaker. If the cig socket dies, I will change it to a USB-dedicated dual output.

As became obvious this past holiday weekend, it seems charging something or other with USB is the way of the future. A rafted alongside boat had no such ability, so my boat became the charge source.
 
Mar 23, 2015
259
Catalina 22 MK-II Dillon, CO
FIgured I'd get a lot of responses on this one. Yes, I will likely replace one of the cig receptacles with a USB plug. I will leave the other, just because it may be useful one day. No specific items for this one ... battery vaccum maybe? So this makes sizing of the fuse ambiguous. I guess that I was more thinking "unswitched" circuit vs. "unprotected" circuit. So ... will likely go to the battery with an inline 5A fuse, 16 ga wire which should be sufficient even for a 20 A fuse (10% drop). That would give me 3 wires directly connected to the battery; one from the solar panel, one to distribution panel, and one to the receptacles.
 

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
I agree with dilochner that a Blue Sea type fuse panel is a good idea. Its a lot neater than a bunch of individual wires on the positive battery terminal and probably safer
 
Mar 23, 2015
259
Catalina 22 MK-II Dillon, CO
The short answer is yes, you can wire directly to the battery.

The long answer involves more. Any circuit coming off the battery should be fused within 7 inches of the battery. The battery post should have no more than 4 connections on the post. For your application, a small sailboat with minimal electrical demands, a Blue Sea Fuse Block would make for a simple neat connection at the battery for up to 4 circuits.
Yup, I like it. Thanks for all the suggestions.
cec
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
You don't need to change the receptical. For 8 bucks from Amazon
I didn't go into it, but my crew said the (single) adaptor like that got very hot to touch, so unplugged their phones. I question the contact surface between the cig socket and adaptor, which is why if it fails I'll go to a hard-wired USB receptical. YMMV, and you can get thos adaptors at any store- even 7-11.
 
Jan 11, 2014
13,113
Sabre 362 113 Fair Haven, NY
While a bit on the pricey side, this USB charger from Blue Sea can handle up to 4.8 amps and senses the charge rate for the device. Also has thermal protection.
 
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jviss

.
Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
While a bit on the pricey side, this USB charger from Blue Sea can handle up to 4.8 amps and senses the charge rate for the device. Also has thermal protection.
Dave, that looks like a good one, but unfortunately doesn't support any of the quick-charge protocols like Quick Charge 3.0 or PowerIQ. I like the Anker products, which are well made and support those protocols. Phones, etc., charge much faster with these.
 

Ward H

.
Nov 7, 2011
3,797
Catalina 30 Mk II Cedar Creek, Bayville NJ
I agree with using Anker products. Be aware of the cheapie chargers at the convenance / drug stores. Don't last and can overheat. You get what you pay for.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,505
CAL 35 Cruiser #21 moored EVERETT WA
In your planning there is a reasonable consideration in keeping the cigarette style charge station and insert a USB charger.

Last January, during the planning for our Extreme Winter Cruise, I asked @mainesail about chargers.I wanted to have a USB C charge interface able to power a MAC Laptop. I received this info regarding his experience and recommendation.
----
Not all USB chargers perform to spec. I have tested many, over 30, and most of them do not do what they claim, especially when they heat up. That said I have had pretty good luck with both performance and relaibility with the Anker USB chargers. Anker does make an USB C product. One thing I like about Anker is that at least some of thier produtcs have actually been UL tested. Can't say the same for the majority of Chinese USB chargers found on Amazon or eBay..​
--
I purchased the Anker charger and it is a great unit.
 
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Jan 11, 2014
13,113
Sabre 362 113 Fair Haven, NY
Last January, during the planning for our Extreme Winter Cruise, I asked @mainesail about chargers.I wanted to have a USB C charge interface able to power a MAC Laptop. I received this info regarding his experience and recommendation.
Ohhhh, you got a new Mac laptop! I'm jealous. :mad:

I use a small, 150 watt pure sine wave inverter to charge my 6 year old MacBook Pro.
 
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Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
I can attest to the Blue Sea USB chargers. My only complaint about the double USB charger with the LED is that the LED is very bright at night. I have 4 of those chargers, two at each end of the cabin, and the LEDs light the cabin at night. Otherwise, no complaints over 7 years and 7 installed in 3 boats. I even gave a spare one to my friend, and he likes them too.
I also have the Blue Sea Blade fuse block. It is very handy, neat, compact, and easy to use.