- Which LEDs could I use?
- How many LEDs could I use?
- How long does the CR2032 Battery last?
- How long does the CR1220 Battery last?
- How long can the conductive thread be?
- Can an E-Textiles circuit be washed?
- Useful links.
I'm thinking of introducing LEDs to my textiles project - which LEDs could I use?
We have a great range of E-Textile compatible LEDs for you to choose from: from Sewable PCB LEDs (top right) to standard (top left) Flashing LEDs, Colour Changing LEDs and, even, a Yellow Candle LED that flickers like a candle flame. The coin cell that you'd need to power an E-Textile circuit provides 3V, therefore, any LED with a supply or forward voltage of around 3V will generally be OK - please click here for the full listing.
How many LEDs could I use in one E-Textiles circuit?
One 3V Coin Cell Battery can run up to 6 Sewable PCB LEDs or up to 6 leaded LEDs (listed in the link above). We have successfully ran up to five colour changing or flashing LEDs from a single (new) 3V Coin Cell Battery. You may be able to run more but it very much depends on the lengths of conductive thread and the type of LEDs that you choose to use. Please note that when multiple colour changing or flashing LEDs are used, the LEDs will not cycle/flash in time with each other. As more LEDs are introduced to a circuit, the dimmer they will be become, which also drains the battery life at a faster rate.
How long does the Lithium 3V CR2032 Coin Cell Battery last?
A typical LED uses about 20mA and the capacity of a CR2032 Coin Cell is 200mAh. See below for a battery life estimate:
- Number of LED(s) in one circuit: 1 - Battery life: 10 hours
- Number of LED(s) in one circuit: 2 - Battery life: 5 hours
- Number of LED(s) in one circuit: 3 - Battery life: 3.3 hours
- Number of LED(s) in one circuit: 4 - Battery life: 2.5 hours
- Number of LED(s) in one circuit: 5 - Battery life: 2 hours
How long does the Lithium 3V CR1220 Coin Cell Battery last?
A typical LED uses about 20mA and the capacity of a (mini) CR1220 Coin Cell is 40mAh. See below for a battery life estimate:
- Number of LED(s) in one circuit: 1 - Battery life: 2 hours
- Number of LED(s) in one circuit: 2 - Battery life: 1 hours
- Number of LED(s) in one circuit: 3 - Battery life: 0.6 hours
- Number of LED(s) in one circuit: 4 - Battery life: 0.5 hours
- Number of LED(s) in one circuit: 5 - Battery life: 0.4 hours
How long can the conductive thread be?
The conductive thread doesn’t work quite as well as a piece of wire so you can’t use really long lengths. If you do go a bit too long then you won’t break anything but the LEDs will be a bit dimmer. In most projects the LEDs will be fairly close to the battery holder but if you do need to put the battery holder further away, we would recommend that you don’t put the LEDs more than 1m away from it. When designing your project it is also worth noting that if a number of LEDs are spread out a long way, then the LEDs furthest from the battery will be slightly dimmer than the LEDs nearest it.
Can an E-Textiles circuit be washed?
Please note that the electronics are not water resistant and should not be washed. So, you've established that you'd like to introduce a number of LEDs to an item of clothing but your first question is: can the item be washed once you've sewn an E-Textiles circuit to it? The answer is yes, but there are a few extra steps that you have to take when assembling your circuit - the battery holder and any switches must be removable, which is simple enough to do! It should only be the conductive thread and the LEDs that get washed. Please make sure that you dry everything properly before use. Note, it should only be the thread and LEDs that get washed - DO NOT MACHINE WASH. The best way to do this would be to attach the cell holder to a separate piece of non-fray fabric with a metal popper on either end...
As for the circuit that you're stitching onto the garment, sew two metal poppers where you would have positioned the coin cell holder, like so (below). 
The cell holder is now ready to be connected to the rest of the circuit using the metal poppers. Join the negative popper in the circuit to the negative popper on the cell holder and join the positive popper in the circuit to the positive popper on the cell holder. This process of joining the coin cell holder to the circuit acts as a switch: when connected, the LEDs will light, when removed the LEDs will deactivate. As well as acting as a switch, this also means that the cell holder can be removed from the circuit to allow for washing. The garment with the LEDs and the conductive thread can be washed by hand in cool water. Do not iron the circuit or tumble dry the product. You are advised to do your own wash test of your circuit before adding it to your product. Learn how to create a washable E-Textiles circuit in our step-by-step guide.
Useful links:
- E-Textiles: an Introduction to our Electro-Fashion Range.
- E-Textiles: a Lesson in Electro-Fashion Components.
- E-Textiles Tutorials & Resources.
- E-Textiles Gallery.
- A look behind the scenes of our Electro-Fashion range.
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