Battery Powered Lighting For Shelving Unit?

raggamuffin415

Arachnosquire
Joined
Nov 12, 2014
Messages
95
Hi All,

Looking to light up my shelving units, more so for display reasons than anything. Problem is there's no electrical outlet by my racks, so I'm looking at some battery powered LED pucks or strips. I wouldn't have em on all the time, so I'm not worried about them running through batteries or anything. Was looking at the Capstone brand LED puck lights for now. What do you guys think? Any suggestions? For some reason I can't paste the url here. Here are the racks (I have 2), and the lights would be adhered to underside of shelves.
 

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Introvertebrate

Arachnodemon
Joined
Dec 18, 2010
Messages
735
You don't want to run an extension cord to the nearest outlet? I'd use a Lowe's shop light with a plain ol' 50 watt bulb, but hey, that's just me.
 

raggamuffin415

Arachnosquire
Joined
Nov 12, 2014
Messages
95
There's a door between the 2 racks, so don't want to have to run an extension cord over it
 

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
8,312
OP, do yourself a favor. Not all LED arrays are the same. The market is flooded with junk and copied quality stuff.
Look for reputable name brands that the store will stand behind. You may get an array that could run 50 to 100 hours on a single charge, or 1 to 5 hours, in the same identical package. Buyer beware.

Look for MaH or aH. Amp hours. How much power the LEDs will use. The problem is many power sources supply more amps and voltage than the LEDs want. The cheap and easy way to reduce the voltage is with a divider. Voltage dividers commonly burn much more current than the LEDs they are powering. For example, my reading light has 4 watts of LEDs but burns nearly 20 watts. The divider burns 16.

So do comparisons and if possible, check that the current use is really what is claimed on the package.
 

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
8,312
To explain LED power supplies. An LED must have the current and voltage restricted. A common LED uses 2 volts at less than 200 milliamps of current. Your average battery pack delivers 5 volts at up to 2 amps or so. A real power regulator consists of 2 capacitors, a resistor or two and a silicon device like a transistor.
A cheap equivalent is a couple of resistors connected end to end. One side goes to the + of the battery, one to the -. The voltage in between the two is correct and the first resistor limits the current. The second resistor burns off all the excess, sending it back into the battery's negative terminal.
The easy way to tell if you are regulating or burning off power is turn the LEDs on for about a minute. Gently warm at the regulator/power in connection = regulator. Hot = divider.

I have two Phillips LED lights. They came in identical packages. One is a real Phillips, costs $10, and uses 7 watts of power. The other is a fake copy, costs a few cents less, and burns a whopping 32 watts for the same exact light output. A massive voltage divider is inside getting it too hot to comfortably hold your finger against. An incandescent bulb would use less power than the fake.

Obviously a voltage divider power supply is unsuitable for battery use as it would quickly drain it.
 

viper69

ArachnoGod
Old Timer
Joined
Dec 8, 2006
Messages
11,537
To explain LED power supplies. An LED must have the current and voltage restricted. A common LED uses 2 volts at less than 200 milliamps of current. Your average battery pack delivers 5 volts at up to 2 amps or so. A real power regulator consists of 2 capacitors, a resistor or two and a silicon device like a transistor.
A cheap equivalent is a couple of resistors connected end to end. One side goes to the + of the battery, one to the -. The voltage in between the two is correct and the first resistor limits the current. The second resistor burns off all the excess, sending it back into the battery's negative terminal.
The easy way to tell if you are regulating or burning off power is turn the LEDs on for about a minute. Gently warm at the regulator/power in connection = regulator. Hot = divider.

I have two Phillips LED lights. They came in identical packages. One is a real Phillips, costs $10, and uses 7 watts of power. The other is a fake copy, costs a few cents less, and burns a whopping 32 watts for the same exact light output. A massive voltage divider is inside getting it too hot to comfortably hold your finger against. An incandescent bulb would use less power than the fake.

Obviously a voltage divider power supply is unsuitable for battery use as it would quickly drain it.
How were you able to ID the knock off if the package was identical?
 

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
8,312
How were you able to ID the knock off if the package was identical?
In that particular case I was modifying all the ceiling lights in the house to accept a normal screw in bulb from the old fashioned Circline<tm> fluorescent. The bulbs were pressed against the plastic diffuser but with such low wattage it wouldn't be a problem. 2 of the 5 fixtures I modified cooked and distorted the diffuser plastic in a few days so I checked. Those two were very hot so put the bulbs on an ammeter. I took one apart and inside was the resistor pair, one a very funky chunky 1200 ohm pushed quite a ways beyond it's designed current and a very real fire hazard. Further testing showed the copper tab was plated steel and the soldering done by hand.
Since then I've been testing all electrical and electronics stuff. Most recently we were given a new cell phone. Alarm bells went off at once as the battery was only a fraction of the weight of the same battery in the old cell phone. Both rated at 2400 mAH but one lasted an hour before needing recharge, the old one was good for 8 to 10.
They put great effort into copying the packaging precisely but the products are always or nearly always pure crap.

Here's a real piss off that happened to a friend last week. He had a cut off saw for several years that was mounted to his work bench. He had to do some work in the field so he bought an identical one. It fried the motor in an hour. So I had him cut the windings out of the beast and mic them. It had the correct sized wire, 22 gauge, but aluminum instead of copper. Both Harbor Freight straight from China.


BTW, what is disconcerting about the faked lights is they normally come packed in cases in quantity. How did the fakes and real ones get so mixed together? That would be a serious achievement if the pirater was able to coordinate with the shipper or distributor.
 
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raggamuffin415

Arachnosquire
Joined
Nov 12, 2014
Messages
95
Thanks for the detailed info... unfortunately you lost me lol. If there are any specific products you guys can suggest that'd be awesome. Sorry if that comes off as rude or ignorant, I just don't anything about electrical!
 
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