Help: Quick add for a blue sea 1039 dual charger (1 Viewer)

[Wompom]

Help me out here.
Trying to pop a Blue sea 1039 USB into the truck for a last minute trip.
I'm debating two things:
1 - add a fuse off the main fuse panel under the steering wheel - which fuse?

2 - jump off the seat heater power under the console. Not sure about this one.

I'm not an electrical wizard.
Long term i'm going to install a fuse panel and do it the "right way" after this trip.

Question is, does anyone see any issue with just running an add a fuse off a switched fuse in the panel?
run that to the outlet, then run a wire to ground somewhere nearby

At most this will have an iphone and ipad charging simulataneously.
Max output is 4.8A

12/24V Dual USB 4.8A Chargers - Switch Mount - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance

www.bluesea.com

 

[Eyedaho]

Add a fuse seems fine as long as you don't overload the circuit. Maybe pick a fuse for a circuit that won't be in simultaneous use with the outlet, like the seat heater one?

 

[e9999]

Always a good idea to add a fuse to any addition.
If you take power off a panel, check that the base circuit is not critical and will stand the 5A.
If in a hurry, why not simply use a USB adapter in the cig lighter? There are duplex extensions etc for that too.
I would not use a key-controlled circuit, but rather an always-on one if it's for charging devices.
It would probably take less time to run a wire from the battery directly with an inline fuse than mucking about the panels if a temp solution.

 

[Wompom]

Add a fuse seems fine as long as you don't overload the circuit. Maybe pick a fuse for a circuit that won't be in simultaneous use with the outlet, like the seat heater one?

Good point - i'd need to do some digging to see what's what. I've added a gauge setup on another add a fuse and don't like using them. Have been waiting for the next run of Hudd expo circuit mounts to come in for a cleaner solution for a fuse panel.

Always a good idea to add a fuse to any addition.
If you take power off a panel, check that the base circuit is not critical and will stand the 5A.
If in a hurry, why not simply use a USB adapter in the cig lighter? There are duplex extensions etc for that too.
I would not use a key-controlled circuit, but rather an always-on one if it's for charging devices.
It would probably take less time to run a wire from the battery directly with an inline fuse than mucking about the panels if a temp solution.

I don't like the interference that the cig plug one i have causes. Even with an expensive nice one, it causes radio/bluetooth music noise.

It will definitely get fused. Add a fuse just seemed faster and simpler to do real quick off the panel. I prefer keyed on, but I guess it doesn't need to be. Since i'm on a single battery still i don't like parasitic draw. But being able to plug a phone in to charge overnight would be sweet. Doubt that'd kill a battery overnight. I'll look at what fuses in the panel could handle it safely, but may just run it off the battery like suggested.

 

[e9999]

None of my 3 cig-lighter USB adapters make radio noise (that I can hear) on my 80 or 100. And if you use an extension you can locate the adapter farther away from the radio. Anyway, with a always-on source, you can charge your electronics at night when not listening to the radio? or use an inverter and 110V charger if that helps with noise? A 100Ah battery should likely give you well over a month worth of phone charging.

 

[Wompom]

None of my 3 cig-lighter USB adapters make radio noise (that I can hear) on my 80 or 100. And if you use an extension you can locate the adapter farther away from the radio. Anyway, with a always-on source, you can charge your electronics at night when not listening to the radio? or use an inverter and 110V charger if that helps with noise? A 100Ah battery should likely give you well over a month worth of phone charging.

Thanks for the tips. I'm a mechanical engineer and can build a motor but electronics scare meh!

 

[TomH]

If you want to mount the USB in the console there's a 3 wire connector under the console that has switched power. I use it to power the relays for my seat heaters. There is also a ground point right there too. This could be a permanent solution.

 

[Wompom]

If you want to mount the USB in the console there's a 3 wire connector under the console that has switched power. I use it to power the relays for my seat heaters. There is also a ground point right there too. This could be a permanent solution.

That's good intel, and what i was curious about. I think those are the factory seat heater connections, no? I wonder if an additional 5amp load would be okay on there.
I'm assuming i'd still want to add an additional fuse off that.

 

[TomH]

That's good intel, and what i was curious about. I think those are the factory seat heater connections, no? I wonder if an additional 5amp load would be okay on there.
I'm assuming i'd still want to add an additional fuse off that.

I think the seat heaters are six pin connectors.

It's my opinion that any circuit in the truck could handle the load of a dual USB connector. If I was doing it I wouldn't add an additional fuse, but again, just my opinion. I'm don't know what the unused connector was designed for but it was certainly expected to take some load that was designed into the existing circuit.

 

[e9999]

Well, it's the total actually running amps that matter, of course. So if you put your charger on a circuit that is designed to handle more than the charger draw, you should be fine if the other load is not on, obviously. For instance, simply don't use the seat heaters at the same time and their fuse should likely be fine since those probably do take more than the charger draw (check). Problem solved, if potentially iffy. But it is so trivially easy to put a small fuse in line with your pigtail that I would do it no matter what, just for peace of mind. Of course, never swap an OEM fuse for a higher rating one, the wires won't like that.
Having said all that, you may want to find out what the actual charger draw is at 12V. I doubt that a phone will actually pull 5A at 5V. That would be one hot phone. So, you are likely dealing with (much?) less than 5A at 12V.

But... Reality check? Have you now spent more time reading mudders blahblahing, and pondering, identifying fuses, and maybe looking for connectors under the dash and under the seats, than it takes to actually pull 2 wires from the battery to the rear of the truck? If it's a quick fix for a surprise trip, that would do good enough. In a pinch (!), you can even get the wires through the door opening so no need to crawl under the truck even...

 

[Wompom]

Yeah just pulling a live battery wire. Now all I can find is my 18ga wire. Thinking it's too small.

 

[e9999]

check an ampacity table. And also the voltage drop. But FWIW, I have several 5A 12V chargers that came OEM with 18ga (or less) wire leads. Although only 3 or 4 feet long.
(I'm sure you know this, but if you go live from the battery a suitable fuse is an absolute must! No shortcuts on that one if you value your truck...)

 

[Wompom]

check an ampacity table. And also the voltage drop. But FWIW, I have several 5A 12V chargers that came OEM with 18ga (or less) wire leads. Although only 3 or 4 feet long.
(I'm sure you know this, but if you go live from the battery a fuse is an absolute must! No shortcuts on that one if you value your truck...)

Yep. Based on the chart it says 4.8a dc max output so was planning on running a 5amp fuse at the battery.
Going to grab a roll of 12ga which is usually what I use for Everything

 

[e9999]

that 4.8A up there is likely the output of the charger per USB port at 5V, not the input current at 12V which is what you need to account for with the fuse.

12ga wire is way overkill for a usb charger, so you're fine there.

 

[Wompom]

that 4.8A up there is likely the output of the charger per USB port at 5V, not the input current at 12V which is what you need to account for with the fuse.

12ga wire is way overkill for a usb charger, so you're fine there.

Yeah I realized that after I posted. Going with 14 since it's the cheapest in a big spool at o'reilly.
Since the max output draw is under 5 Amps is a 5 amp fuse enough?

 

[e9999]

I see now it says 4.8A *Total* in the listing. So, that may likely mean it is with both ports running, or 2.4A per port. That is more likely to be the case than 4.8A each, which is quite high for USB.
So, that is about 25W total cuz USBs output at 5V. That would then in turn be around 2A at 13V, say 2.5A with any losses in the electronics . So, you could expect the current in the 14ga wire to be 2.5A or less, roughly. And the fuse should be a bit more than that to be still safe but not overly iffy. The 14 ga should easily handle that current, so that there is likely not a heat problem with it (but if very long - check for voltage drop, although that is unlikely to be an issue, if the charger will function on 9V as it says).

I would buy an inline fuse holder of the same size as the other fuses in your truck and get an assortment of matching fuses. That can be handy in the field. Then I would try first a 2.5 or 3A fuse and see if it pops with devices charging on both ports. (You probably can't trust any chinesium specs.)

Now, if it is really 4.8A each port -probably not- you need to double all the above.

Remember, though, that the current rating of the device is only telling you what it can handle safely at max and is designed for. The real current is actually determined by the load. So you may never draw those numbers if the load is reasonable. For example, my phone typically only draws 1A or less at 5V from the charger, even though it may say 2.1A (max) output. Conversely, if you have a short, you could draw a large current and blow something up, hopefully the fuse first.

The basic principle is that the fuse should be such that everything is safe at least until the fuse pops. IOW, the fuse should be the weakest link in the chain -by design. And a bigger fuse than necessary can be a safety hazard because it could allow something somewhere to overheat and start a fire; and a cost hazard because it could allow an expensive device to blow rather than a cheap fuse.

 

[Wompom]

I see now it says 4.8A *Total* in the listing. So, that may likely mean it is with both ports running, or 2.4A per port. That is more likely to be the case than 4.8A each, which is quite high for USB.
So, that is about 25W total cuz USBs output at 5V. That would then in turn be around 2A at 13V, say 2.5A with any losses in the electronics . So, you could expect the current in the 14ga wire to be 2.5A or less, roughly. And the fuse should be a bit more than that to be still safe but not overly iffy. The 14 ga should easily handle that current, so that there is likely not a heat problem with it (but if very long - check for voltage drop, although that is unlikely to be an issue, if the charger will function on 9V as it says).

I would buy an inline fuse holder of the same size as the other fuses in your truck and get an assortment of matching fuses. That can be handy in the field. Then I would try first a 2.5 or 3A fuse and see if it pops with devices charging on both ports. (You probably can't trust any chinesium specs.)

Now, if it is really 4.8A each port -probably not- you need to double all the above.

Remember, though, that the current rating of the device is only telling you what it can handle safely at max and is designed for. The real current is actually determined by the load. So you may never draw those numbers if the load is reasonable. For example, my phone typically only draws 1A or less at 5V from the charger, even though it may say 2.1A (max) output. Conversely, if you have a short, you could draw a large current and blow something up, hopefully the fuse first.

The basic principle is that the fuse should be such that everything is safe at least until the fuse pops. IOW, the fuse should be the weakest link in the chain -by design. And a bigger fuse than necessary can be a safety hazard because it could allow something somewhere to overheat and start a fire; and a cost hazard because it could allow an expensive device to blow rather than a cheap fuse.

Appreciate all your insight.
Ended up hard wiring off battery with an online 5amp fuse and no issues so far on the trip. Was way overthinking this in crunch mode!