Help with battery powered led lights...

[mossman70]

Hi,
Not sure if 'Electrics UK' is the appropriate forum to post as its a question about battery powered LED lights so if I've posted in the wrong section can it be moved to the correct one please....

I'm after some advice about letter lights I've purchased and the best way to wire them all together to work from one switch.
If you look at the photos you will see the letter 'S' I have purchased along with 3 others so have 4 in total with each one having to be powered by batteries individually.
They all use the same power which is 2 x AA batterys obvioulsly 1.5volts for each giving me a total of 4 letters at 12volts.
As I said they are powered individually and I want to be able to turn them all on and off with one switch with one power supply so I would appreciate any info on the best way to do this, I do need the power supply to be quite compact.
Many thanks

Edit - Could it be as simple as extending the on/off switch wires from all 4 letters to connect to just one switch keeping the AA batteries in each letter?

 

[OwainDIYer]

No, 4 letters at 3 volts. They're wired in parallel.

The two 1.5V batteries will be wired in series to give 3V.

easiest way will be to get some thin twin flex, connect that to the two battery terminals (at the switch end) on each light and connect at the end through a switch to a separate battery holder. As this will be supplying several lights you might want to use 2xC or 2xD batteries as they have much higher capacity than AA. You will need to observe correct polarity + and - throughout, as the lights may be damaged if the polarity is the wrong way round.

2 x AA battery holder - Ebay may be the cheapest source if this is all you need.

You can get them with press-studs on to match a PP3 snap connector instead of leads or solder tags. Using a PP3 snap connector as a switch might be easiest, especially if you aren't able to solder.

 

[mossman70]

Thanks pal, I can solder so the first one looks the best way then, many thanks for your help

 

[bernardgreen]

Some of these letters have LED elements that rely partly on the internal resistance of the battery as the current control. Larger batteries with lower internal resistance may allow higher current flow in the LED elements.

 

[mossman70]

Some of these letters have LED elements that rely partly on the internal resistance of the battery as the current control. Larger batteries with lower internal resistance may allow higher current flow in the LED elements.

Could this knacker the bulbs then?

 

[mossman70]

This be OK then, 2x D battery case with switch?

 

[EFLImpudence]

Some of these letters have LED elements that rely partly on the internal resistance of the battery as the current control.

Would it work with all the batteries in series and all the lamps in series?

 

[bernardgreen]

Could this knacker the bulbs then?

It might reduce their life a bit, depends on the quality of the elements.

Two D cells in series giving three volts should be OK to supply all 4 letters connected in parallel.

 

[mossman70]

It might reduce their life a bit, depends on the quality of the elements.

Two D cells in series giving three volts should be OK to supply all 4 letters connected in parallel.

Bernard, the quality isn't going to be that great for the price I paid for them so I'll get the 2x D holder and get them wired up in parallel, thank you
and thanks to all for your help guys

 

[SUNRAY]

Some of these letters have LED elements that rely partly on the internal resistance of the battery as the current control. Larger batteries with lower internal resistance may allow higher current flow in the LED elements.

Correct.
I've handled some lights for displaying glass crystalware which specified 2x D NiCad and emphasised not to use alkaline or zinc batteries. Of course the trader did not have a Scooby and used Duracells, none of the LEDs lasted as long as the first set of batteries.

 

[mossman70]

Quick update guys, battery holder came and I'd already wired the lights in parallel and the holder was in series anyway. Connected it up and works a treat so many thanks

 

[SUNRAY]

Thank you for the update, we appreciate it.