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I want to wire a 12 volt cigarette style outlet into my trunk for a 100 Watt inverter. I picked the 100 watt unit because my computer charger states its output is 65 watts, and I figured I'd have a little reserve capacity with the 100 watt inverter. So if P=I x E, 100 watts = amps x 14 volts, or amps needed for this inverter would be 100/14= 7 amps, more or less. I figured I'd run a 10 amp fused circuit with 16 AWG stranded copper wire. Does this sound right, or am I overlooking something?
 

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Sounds like you're on the right track. Just checked amperage input to my HP laptop charger and it says 1.7 Amp in which surprised me it was that small a value. I think you could get be with a 5 amp fuse also. I'd wire it through a relay triggered with the aux power circuit so you can't leave it powered on and drain your bike battery. You might consider a automotive laptop 12v charger also, it would be smaller than an inverter and laptop 110v charger. I like your idea. Do you need a full up laptop? Today's tablets are very capable and easier to transport. Mine charges of a USB port. Also having just repaired my laptop most don't handle the long term vibration well, loose screws can be problematic.

Sent from my Moto Z (2) using Tapatalk
 

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My 5amp fuse guess could be off, inverters are not extremely efficient and as I recall mine had a fuse in the power line. That fuse should give you a good idea what it figured as too much current. I have a 750w inverter that has three 30 amp fuses! I no longer have a 100 watt. It shut off too often on cage trips.

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Sounds like you're on the right track. Just checked amperage input to my HP laptop charger and it says 1.7 Amp in which surprised me it was that small a value. I think you could get be with a 5 amp fuse also. I'd wire it through a relay triggered with the aux power circuit so you can't leave it powered on and drain your bike battery. You might consider a automotive laptop 12v charger also, it would be smaller than an inverter and laptop 110v charger. I like your idea. Do you need a full up laptop? Today's tablets are very capable and easier to transport. Mine charges of a USB port. Also having just repaired my laptop most don't handle the long term vibration well, loose screws can be problematic.

Sent from my Moto Z (2) using Tapatalk
Are you sure it's not 1.7A at 120V?
 

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Yep. Still US statesside voltage varies a bit but is 110-120V, I typed 110v out of habit. My HP's power block accepts 100-240V as input, I can use it overseas where standard is based on 220v. I was Googling for an automotive laptop charger and found a few for HP models that were less than $20. Pretty sure that's cheaper than an inverter, certainly less than mine. Think I'll find one for my specific model!
 

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It's possible you are giving yourself work. You laptop may well run on 12v directly from your bike. Have a look at the output voltage on your laptop power supply, typically 18v (ish) this will be regulated down inside the laptop.

I'd try 12v first. Mine has 19.5v on its power supply but it's happy to run directly connected to my car.
 

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Discussion Starter #7
Sounds like you're on the right track. Just checked amperage input to my HP laptop charger and it says 1.7 Amp in which surprised me it was that small a value. I think you could get be with a 5 amp fuse also. I'd wire it through a relay triggered with the aux power circuit so you can't leave it powered on and drain your bike battery. You might consider a automotive laptop 12v charger also, it would be smaller than an inverter and laptop 110v charger. I like your idea. Do you need a full up laptop? Today's tablets are very capable and easier to transport. Mine charges of a USB port. Also having just repaired my laptop most don't handle the long term vibration well, loose screws can be problematic.

Sent from my Moto Z (2) using Tapatalk
I'm not a big fan of tablets; I work a lot, lot faster on hard button keyboards and I had already considered your suggestion and ruled it out. As for size, these 100 W inverters are pretty small, about the size of 4 packs of playing cards stacked 2x2 but I'll search out 12v car chargers since the $$ is prob about $20-30 I'd guess. The vibration could be a factor, as you say. I'll have to think about that a bit more. Thanks for the input!
 

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Suggestion can you get a a 12vdc charger for you computer and skip using the inverter completely ? I am planing to charge my pc by using a 12dc to 19.5 inverter.

The bust bucket inverters I have in my junk box are 3A adjustable up to 35Vdc.
 
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Discussion Starter #9
It's possible you are giving yourself work. You laptop may well run on 12v directly from your bike. Have a look at the output voltage on your laptop power supply, typically 18v (ish) this will be regulated down inside the laptop.

I'd try 12v first. Mine has 19.5v on its power supply but it's happy to run directly connected to my car.
:surprise: Well, I did not know that. My Lenovo puts out 19.5 volts so I never thought it would run and charge without a hiccup at just 12-14 volts. Do you think 14 volts would charge the battery, or cause problems with charging the battery? I like trying your suggestion. Now all I have to do is find the correct male plug in to try as "they're all the same only different." :nerd:
 

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Discussion Starter #11
Suggestion can you get a a 12vdc charger for you computer and skip using the inverter completely ? I am planing to charge my pc by using a 12dc to 19.5 inverter.

The bust bucket inverters I have in my junk box are 3A adjustable up to 35Vdc.
So that's 2 votes for a dedicated 12v charger instead of an inverter. Plus maybe even a straight in 14v line to the laptop. Very glad I asked about this. Sounds like inverters are not quite the way to go for me.

I'll still be wiring the trunk outlet to add utility and options (e.g., trunk and saddlebag switched LED lights) but think I'll step back from the inverter idea. Thanks all.
 

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Inverters are highly inefficient, due to the power lost as heat during the conversion.

It you *really* wanna get crazy, try to find the specs for the *battery* in the laptop you're wanting to charge.

Odd voltages (like 19.5) are picked for a specific reason. Dependent upon the battery chemistry, it *can* be harmful to the battery!

"A lead-acid charger that can be set to charge no higher than 14.6v can be used for regular charging and then MUST be disconnected after the battery is fully charged. DO NOT leave the lead-acid charger connected to maintain or store the battery, because most will NOT maintain the proper voltage charge algorithm for lithium batteries and damage will occur to the battery and this is not covered under battery warranty."

http://www.enerdrive.com.au/can-charge-lithium-battery-lead-acid-charger/

In this case, that alternator on the bike is ~equivalent` to a lead-acid charger.
 

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Yep. Still US statesside voltage varies a bit but is 110-120V, I typed 110v out of habit. My HP's power block accepts 100-240V as input, I can use it overseas where standard is based on 220v. I was Googling for an automotive laptop charger and found a few for HP models that were less than $20. Pretty sure that's cheaper than an inverter, certainly less than mine. Think I'll find one for my specific model!

Yes, I meant is it 1.7A at 110/120 V; that sounds like it is what you meant.

So then to produce the same wattage and run off of 12V, an inverter in the bike will need current approx 10 times larger than the 110/120 current ( maybe more, depending on inverter)

So maybe a 12V / 20A circuit required from the 12V source to power the inverter?


All I was really getting at is a 2A or 5A fuse/circuit at 12V to an inverter isn't gonna provide the necessary wattage.
2A +/- is likely to be lots when drawn from a 110/120V source.

Mine has a 180W charger (19 something volt output at whatever amps) so at 120v it'in the 2A range.
But source from 12V, 180W requires 180/12 or 15A.
 

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Do you think 14 volts would charge the battery, or cause problems with charging the battery? I like trying your suggestion. Now all I have to do is find the correct male plug in to try as "they're all the same only different." :nerd:
I dunno about the battery but give it a try. The computer will regulate the charge for the laptop battery just as it does when its connected to the mains power supply. After all, you can leave it connected to mains indefinitely. Low voltage won't do any harm, if there's an issue the laptop simply won't work just as it does when its internal battery is discharged.

With my laptop I've used it for playing DVD's in my caravan and that is just a car battery supply so not even 14volts. I didn't pay any attention to battery charging though.
 

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Well Gang,
I'm certainly no expert on any of this but, I think there's too much OVERTHINKING about much of this. Here's what I did to the Wing about 8 years ago. It, to me, is simple. What I did was, take two, 8GA wires, one black and one red, and run them directly from the battery posts, along the frame, and up into the left rear pocket of the trunk. Then, I installed what's called an Anderson SB-50 connector on those two wires. Then, I installed, a triple power point unit in the trunk. I ran the wires from that triple power point, through the back of the trunk and into the corner pocket where the wires from the battery and connector are. I then installed another SB-50 connector on those wires from the power points.

I then installed the same SB-50 connectors on:

1. My portable Slime compressor
2. A battery maintainer/charger
3. An 8' long, 8GA set of jumper cables.

Now, when I want power in that trunk, I plug the two SB-connectors together in that pocket. The wires from the triple power points are 10GA wires so, I can power up anything I want in that trunk and charge anything, in any way. Or, if I need a jump for some odd reason or, some other rider needs a jump, I can break out my 8GA x 8' long Jumpers, plug the two SB-Connectors together in that pocket and, the other end of the jumpers uses regular alligator clips.

Or, If I need air or, someone else needs air, I break out my Slime compressor, plug in the SB-50 connectors together in the pocket and, I've got air. And finally, if the bike's gonna be sitting for a while, I plug in my battery maintainer/charger to that plug and, it's being charged.

Those power points could easily handle a 100 or more watt inverter. It doesn't matter what kind of power loss there is. If you're running the bike down the road, you've got plenty of electrical power.
Scott
 

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Just out of curiosity what size fuse and where do you have it installed ?
 

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Just out of curiosity what size fuse and where do you have it installed ?
eddiepants,
If you're addressing me, I don't have any fuses in the system. I know, I know, there probably should be one but, the cables (8GA) from the battery, are so secured that, they haven't moved in over 8 years since I did that project. They can't move which, means there's no etching or potential chafing. If I ever do decide to fuse that system, it's gonna be a big one and, maybe mid length between the battery and the entrance into the side pocket.
Scott
 

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Yes I was addressing you. I was not criticizing I was just curious . After all it is your bike and you are free to do as you please with it just like I am with mine.


By the way very nice install.
 

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eddiepants,
I was not insinuating you were criticizing me, not at all. I was only admitting that I SHOULD have a fuse in the system but, I don't. That SB-50 (stands for 50 amp) is a great fool-proof system. You can't hook things up incorrectly. There are other types of 2-wire plugs out there too. One is the rubber style that is identical to the 4-wire trailer plug only it's two wires. I just like the SB-50 style systems. When on the FD, we had service trucks that had the 350 amp versions of those plugs, built into the front grill for 2/0 jumper cables to jump our dead fire trucks. That's where I got the idea of those plugs.

Anyway, thanks for the nice comments. I have the same SB-50 connector, mounted to the top inner section of the front bumper of our Jeep. When it comes time for airing up the tires after a days trails, I simply plug in my air compressor (Viair 400P compressor) to that plug and air things up.
Scott
 
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Discussion Starter #20
Well Gang,
I'm certainly no expert on any of this but, I think there's too much OVERTHINKING about much of this.
Scott
It is a nice install and I like your location for your needs. Looks like an ideal use for that passenger cubbyhole, too. I was the OP,and I need the computer charger feature and not the things you needed; plus, I need the computer in the trunk obviously. With that gauge of wire you used I personally wouldn't feel good about not having a fuse, especially since it goes right to the battery. But for your needs and wants I think it looks great, as do those SB-50 connectors. Good things for me to consider. Thanks.
 
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