Efficient LEDs for night light?

[chbla]

Hi there,

I have two sheds (3x3m each) that have no electricity so I plan to add solar lights (switch, not motion triggered).
I figured it makes sense to start with the leds so I can test and see what kind of battery and solar panel I need.

Can anyone suggest efficient (but not too expensive) LEDs for this purpose? I have absolutely no experience here.
Aliexpress preferred

Thank you,
Christoph

[Nca78]

Hello Christoph,

I'm making some backup lights to use in my home as I have frequent power cuts and I decided to use 3020 leds, I paid just over 1$ for 100 on AliExpress. I have 18650 cells from old laptop batteries so I don't care if it's not really efficient (forward voltage is 2.7V) as I have plenty of runtime for 20-40 leds. I tested with a 50Ohms resistor directly on the battery and it emits a fair amount of light for such a tiny LED. And it's not heating at all, as opposed to 12V LED strips.
You could have more freedom for panel/battery if using a step up converter converting to a voltage like 5.5-6V, just above forward voltage of 2 LEDS in series so you would have minimal loss in the series resistor.
That is if you are ready to solder a lot of leds, of course, else go for led strips, 3020/3014 formats seem to be more efficient.

https://www.aliexpress.com/snapshot/.html?orderId=30666345235284

[mfalkvidd]

@nca78 that link seems to require login

[gohan]

If you are going to use a 12v lead acid battery to store your solar power, I bought some of these https://www.banggood.com/50cm-9W-1800lm-36-SMD-7020-Waterproof-IP44-LED-Rigid-Strip-Cabinet-Light-DC-12V-p-1016898.html
Probably, for a 3x3m shed, 1800lm are a bit overkill but for the price I don't know if you can find anything better

[NeverDie]

@chbla said in Efficient LEDs for night light?:

Can anyone suggest efficient (but not too expensive) LEDs for this purpose?

226 lumens/watt, and not expensive:
https://www.digikey.com/product-detail/en/everlight-electronics-co-ltd/62-227ET-KK7D-3M5050X6Y62629U6-2T-EU/1080-1530-1-ND/7930865

[zboblamont]

@chbla In addition to @gohan suggestion, if the shed ceilings will take staples or a glue, you may find it easier to cut and fix 5m rolls of 12v waterproof (IP65) LED strings in branches which you can switch out or in to give more or less light... At $10 or less per roll, it makes little sense to make your own...
If the shed gets damp (and most do), only the joints are exposed to moisture, easily taped or siliconed over. Most tapes come as self adhesive but rarely are reliable, I used a staple gun with staples just over the tape width to fix, no problems.

Pick your preferred colour temperature, the most efficient lumens/W, order however many rolls needed, done and dusted.. If you need more, easy enough to add more...

[chbla]

Thanks for the suggestions! I think I will first try the LED stripe way, it's probably the easiest for now.

[JohnRob]

I've added LED strips under my stair threads for night use. I've learned the "Daylight" (most blue / harsh of the white) is the most efficient. It seems to make the "warm" whites some of the brightness is "consumed".

My lights are running at ~ 1% on time (153 hz) and work great at night. There are 6 meters of light consuming 0.5 watts (including the AC adapter). The cost of the LED strips is trivial. Look on ebay, you can probable get 2 or 3 different kinds for < $10 total and see which you like best.