Hotel rooms, and easily charging a
lot of batteries all at once on the cheap!

When traveling, it can be a problem charging all of your batteries in hotel rooms, who are known to not have a superabundance of electrical outlets in their rooms.

There is a small, lightweight, easy to pack and cheap solution: Add-A-Tap to the rescue. Each Add-A-Tap can add 1 additional electrical outlet on lamp cord, also called Zip cord. This small item literally snaps onto any  SPT-1 Lamp Wire that you have in your home. It can also be made so you can plug many chargers into a cord you make for yourself. Parts list below.

This does require to do a little bit of electrical work: Striping the wire, putting a wire on a screw terminal and tightening it and the other wire on the other screw terminal. There are no polarity issues with this, so either wire can go on either screw terminal.

If you are hesitant to do this, go here and follow the directions, with illustrations.
https://www.wikihow.com/Replace-the-Plug-on-a-Lamp

The parts

1 – You can buy the Add-A-Tap here:
https://www.zackelectronics.com/cooper-wiring-devices-2609w-bu-nonpolarized-add-a-tap-10a-in-line-outlet-for-use-with-spt-1-white.html

Count the number you need, I suggest you buy 1 or 2 extras as they do not always work and sometimes the sharp metal teeth do not make good contact and they will arc, and not work. I remove them, (Easy, look for the metal tab on the outlet) move it a half inch away, and re-install the outlet.

Suggestion, buy extras and make 2 of these cables in case one grows feet and walks off the job.

2 – Home depot sells 10 feet of lamp cord for $3.38, see below.

3 – Then you need a plug and an end of wire outlet:  https://www.aliexpress.us/item/2255799833825429.html – Make sure you select both Male & Female. The Plug kit:

How many chargers can I plug into this cord?

That depends the Amp draw on your chargers, example. For most Canon DSLR, and some mirrorless cameras, the amp draw of the charger is 0.15 amps. Which is almost nothing. You could plug in 60+ Canon LC-E6 chargers with no problem. Here is how to know this, look on your charger and look for Input amps, sometimes there will not be an amp value given, if so look for VA, which stands for Volt Amps, see below. Technically VA is a more accurate standard.

If it is VA, use this: https://www.rapidtables.com/calc/electric/va-to-amps-calculator.html – where it asks for Phase, choose single.
Then enter the VA value. In this example the VA is 18VA.
Where it is asking: “Enter line to line volts:” enter 120, the voltage for the entire U.S.
If you are not in the US, check to see what voltage you have. MOST of the world uses 240Volts.
Canada, Japan use 120 Volts
Mexico uses 127 volts, but 7 more volts is not a problem for US devices.

Example:

How to find how many amps my charger draws (Uses). All of your electric, electronic items will state this. Either in amps or VA.

This charger draws a maximum of 0.15 amps.

Next example, Motorola 2-way radio chargers for a CP200, the standard radio for the film industry. Here it shows 1.0 A, “A” meaning amps. Since the 18 gauge wire is rated for 10 amps, you could use up to 10 of these chargers safely.

Little cell phone charger. 0.4 Amps – meaning this can safely charge 25 cell phone batteries if all the chargers were the same amp draw.

Look at all the chargers you travel with, camera batteries, cellphone chargers, laptop chargers, tablet chargers, monitor batteries, any other item you need to charge or plug into . Add all the amp draw on every battery charger and as long as the total is not over 10 amps, you only need to purchase one set of parts: the wire, the plug, the last outlet on the end of the wire and how many add-a-tap outlets that you are going to snap on the cord. If your amp draw exceeds 10 amps, you will need to make up another cord and add-a-tap outlets for your needs. I travel with 3 cords and normally I just use one. Spares are good.

Installation 

This does require you to do simple electrical work. As long as you do not do this when the plug is plug into the wall outlet, your will be fine. If you are concerned, go here to see step by step:
https://www.wikihow.com/Replace-the-Plug-on-a-Lamp

First, install the wire onto the plug, the part that will plug into the wall outlet. Then about 18″ away from the plug, add your first Add-A-Tap outlet by snapping it on the cord.

If all of your charging devices have a electric cord, then you can add the Add-A-Tap outlets close together.

However, if the chargers are one solid block, I suggest you install one add-a-tap outlet, then plug in the charger to show you where the next outlet needs to go.

When traveling internationally, MAKE SURE to look at every electric/electronic device and look for the VOLTAGE! This is critical as some devices are built for a single voltage, like 120 Volts in the U.S. and 240 Volts in most of the world. Look carefully at the label and look for the number of Volts, can also be just a letter V.  If it shows 120V or 120 Volts, this will turn into smoke when plugged into 240 volt outlet.

If, however it shows 100-240V or 100-240Volts, you are good. And do not assume that all of your devices are the same, look at all of them to be sure that they are not just 120 volts.

MOST OF THE WORLD is 240 volts.

I hope this is useful.

ST