It is like a wall outlet in your house.  It just sits there, and if you want power, there it is.  It is where you want it, it won't go anywhere, and that's the beauty of it.  The only difference is the power is 12V vehicle power, not house current.

We are confident that you can draw up to 15A (180W) without incident, if you use direct battery connection.  Of course, your charging system may have a much lower limit, and dirty or corroded connections could overheat at this current.

Under the usual conditions of weathering and neglect, extended currents above 7.5A may cause trouble in open air.  In an insulated space, these connections can get hot enough to burn skin with extended currents over 3.75A.

Yes.  Though motorcycles with classic tubular frames and minimal bodywork have the most mounting options, there are a few suitable locations on any bike.  Unit will even run on old 6V systems, though you would have to find 6V accessories to go with it.  To use as directed, the bike must have a battery and charging system, though if you are good with electronics, you could find a way to use it on anything.

The !!!MANIC Salamander line of zip-on power outlets attaches with "Zip Ties," or "Wire Ties," included.  The base of the unit is always kept from the paint by a rubber backing.  They are black, thus easy to hide.  This is the only line of SAE or 12mm connectors that attaches directly to tubes or the motorcycle frame, allowing an unmatched variety of location options, with the tidiness and security of a solid attachment.

I wanted to do that.  But when I looked into it, there were so many tube sizes to make clamps for, it wasn't funny.  And machined clamps need to be made for only one tube size.   In the end, it would mean way too much money in inventory, and the price would raise by at least $30.  Who needs that?

We do, in the SAE style.  Widder is out of business, so we will not be bothering with a new product for the 12mm style.

The SAE (Society of Automotive Engineers) connector standard is a family of all-weather low-voltage, medium current connectors.  It is defined by a standard contact form, spacing, and arrangement, and in certain motor vehicle applications, the purpose of each conductor is also specified.  For our purposes, suffice it to say that on the side of the connection that produces the power (battery side), the rubber-shrouded female conductor is the hot wire, going to the + terminal.  The most common place for an SAE connector in the life of the average person, is the connection used to plug in a trailer towed behind a vehicle, so the lights on the trailer work in sync with the lights on the car.  In motorcycling, the two-conductor version has been adapted by many companies as the standard power connector for 12V systems.  Among the companies supplying SAE power connections on their products are:  Aerostich, Battery Tender, CyclePump (sp?) and older Gerbing equipment.

Three principal advantages:  They fit tight and don't pull out accidentally.  They are small.  They are polarized, so you can use them easily with electronic equipment.

They are hard to grip with gloves.  They can be hard to connect and disconnect when new, too easy when old.

12mm refers to the spacing between the conductors.  This connector style was designed as a home television antenna connector, in Germany.  However, the contact area is sufficient to carry a great deal of current.   Between that and ready availability, I suppose we can understand why Widder decided to use it as their connection for electric clothing.  Widder now makes gear for Harley Davidson, so Harley electric clothing also uses this connector.  BMW uses it as well, for some of their gear.  From my limited experience, it appears Widder has standardized on the female connector as the battery side, and as you look down at the screw terminals with the sockets pointed ahead, the hot wire is to the right.

Easy, smooth feel.  Easy to plug in and unplug.  Highly serviceable, with screw-down wire attachment.  You need a jeweller's slotted screwdriver.

They are out of production.  If you can find them, extra connectors  have identical bodies for the male and female side.  So you can stick a pin and a receptacle in the same plastic body.   If you take a cue from the SAE folks and put a receptacle on the hot wire coming from the battery, and a pin to the ground wire, you get a polarized plug.  Unfortunately for polarization, Later Widder products were manufactured with rubber-molded connectors, which cannot be mixed and matched in this way.

For heating, lighting and electronics, you want the smallest fuse that is more than 10% over the rated current of your product.   The rated current is the wattage divided by 12, in 12V systems.  So for example, if your vest is 45W, it draws 45/12 = 3.75A.  10% more than 3.75 is 1.1 * 3.75 = 4.125.  Use a 5A fuse.  If the manufacturer supplied or recommended a fuse size, do what they do.  For motorized devices, you may need to go higher to handle startup surges.  For double outlets, size to fuse to the nearest size larger than the sum of the currents of  the accessories you expect to connect.

The thicker the wire, the lower the resistance.  The lower the resistance, the less power is lost in the wire in the form of heat.  Two reasons not to lose power:  You might want it for something else, like running all those accessories.  Also, the heat generated can shorten the life of the wire and the things connected to it, or start a fire, in extreme cases.  When sizing our wires, we use the National Electrical Code as a starting point.  Even though it is mostly for buildings and appliances, their current ratings for different wire gauges are a good rule of thumb.  For instance, The NEC says that 14ga wire is good for up to 15A.  All that means is that they consider that gauge of wire not to be a fire hazard, and have an acceptably small voltage drop, not to waste too much power.  But a heavier (smaller number) gauge always runs cooler and wastes less energy.

Yes and no.  You'll WASTE less power because more of the power will be used as light.  But you will USE more power, due to the higher voltage available at the headlight, which will burn brighter.  So this is no solution to your electrical system being overloaded.

No.   Your charging system has a certain capacity.  The generator/ alternator will have a rating, but it is typically a maximum rating, which will only be realized at high RPM.  So if you just tour, you can use that rating, subtracting the wattage or current of everything else on your bike, and see what you have left over.  However, if you don't keep the revs up, you start discharging the battery, which is bad for the battery, and sometimes makes it so you can't start the bike again.  Whoops.

The most certain method is to measure battery voltage, with the accessory plugged in.  The bike should be able to hold 13V at anything over idle, with nothing connected.  With your accessory turned on, rev the bike up to your normal highway cruising RPM, and see if the voltage is above 13V.  If it is, you are good for the highway.  Now bring the revs down to half the cruising revs on the street, and see if it can still hold 13V or more.  If so, you're safe on the street.  If you can't hold 13V, you will need to play it by ear- measure your battery voltage after each ride for a while, with the ignition on, but the motor off.  Write down the numbers and dates.  If you see voltage falling day by day, then you have to keep the revs up more, or use the accessory less.

Get a digital multimeter.  An adequate one can be found at Radio Shack.  Set it to the DC V setting, with the range switch (if any) set to the next number over 16V.  Make sure the black wire is in the COM jack, and the red lead is in the V/ohm/A spot.  Hold the black probe to the - terminal of the battery, and the red lead to the + terminal.  Wiggle the leads around, pressing them against the terminals, until the reading stays steady, only changing by small amounts.  Read and record the voltage.

Note:  some of these techniques, regarding lighting, may not be street legal.  Consult local regulations. Switch to LED tail light; about 10- 15W saved per taillight bulb. Switch to HID headlight.  Expensive, but frees up 20W per headlamp. Do not use a rheostat (variable resistor), series or dropping resistor to control your heated clothing to less than full power.  These units waste most of the extra power.  use a bimetallic strip thermostat, or better, a switching electronic thermostat.   These units are much more efficient. On systems with dual headlights that each have both hi/lo beam, disconnect one of the bulbs.  55W saved.

LED brake lights and turn signals help too, but they are not as important because they aren't on for long.  Additionally, most LED turn-signals don't save any power at all, since they are designed to draw the same as an incandescent bulb, because mechanical flashers depend on a certain amount of current through the bulbs to flash.  You can now buy electronic flasher units at auto parts stores.  Get the kind that accepts a variable number of lights.  This means they do not depend on a certain current to work properly.  This kind of flasher works with LED signal lights that do not have a shunt resistor, allowing you to save that power.

Clean and tighten connections to the main fuse, regulator, rectifier, generator/alternator, battery, ignition key switch.  Coat with dielectric grease.  This eliminates power losses in the charging system. Run at higher revs in town.  Not graceful, but gets the job done in a pinch. Get a heavy-duty stator.  There are manufacturers that make specially-wound stators for higher capacity.  You will need to buy a heavier regulator and rectifier, as well.