LED lights dimming after several minutes

[heng512]

Hi, I installed an LED strip for my kitchen counter. Since I'm living in an apartment, I didn't want anything too permanent, so I decided to to power the LED strip using rechargeable batteries.

The power specification for the LED strip is 12V DC. Since rechargeable batteries (AA) are 1.2V, I used 10 batteries. When it powers on, the LED strip will be at the regular brightness that I would expect. However, I've noticed that after several minutes, the light output would dim.

Would using rechargeable batteries be causing this? I can go out and buy 10 regular AA to test it, but I wanted to check here first to see if anyone has an answer.

 

[Sadlercomfort]

The voltage seems perfectly fine for the application.

How long is the strip? The smd leds may be small but can consume alot of current if your running a few meters.

I recently brought a 5m strip myself, which consumes 12v, 5A! If I used batteries I would experience the same issue your having.

It might be more practical to use a dc adapter, rated properly. But you need to know the current draw of your strip first.

 

[Sadlercomfort]

If you know how many leds are in the strip you could find out the current draw that way.

Let's say 100 leds at 20mA:
100×0.02=2A

Then a 12V, 2A adapter would be suitable. It's a more permanent than batteries but at least they won't discharge after a few hours.

 

[heng512]

Thanks for the response. The strip is 5 meters, with 300 LEDs.

I bought it on Amazon, here's the link: http://www.amazon.com/gp/product/B00HSF65MC?psc=1&redirect=true&ref_=oh_aui_search_detailpage

I actually bought two, and the first one I installed in my closet, with a magnetic on/off switch. Since the light is only on for at most a minute, there was no issue with the LED dimming.

 

[Sadlercomfort]

Same led type as I have! Those 300 leds consume 2A.

So a 12V, 2A adapter or higher current is needed.


I think your batteries setup might discharge about every 10 hours. Depending on there current rating.

Still I would recommend a DC Adapter, these are really common 12v, 2A so you might find one knocking around the house.

 

[heng512]

Great, thanks for the information. I guess for regular used lights that are one for a while should probably be plugged in.

 

[Sadlercomfort]

No problem

 

[Martaine2005]

I guess for regular used lights that are one for a while should probably be plugged in.

Sorry can you explain that again?
Ash (sadlercomfort) gave a very nice explanation of what power supply to use.
You can go a little further and buy/use a supply that has a higher Amperage output. Like a 3Amp to keep it cooler.

Martin

 

[Sadlercomfort]

I guess for regular used lights

Frequently used lights

Yeah, a higher rated adapter would run comfortably without being stressed.