Converting 120v AC to battery power

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Old 10-16-17, 03:01 PM
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Question Converting 120v AC to battery power

Apologies if this has been covered before anywhere (I did search ) but im looking to power a string of falling star Christmas lights via battery. Can this be done? My end need is simply a strip of LEDs that light up in the same way these falling star lights do, but they have to be mobile and lightweight as i'm using them in a wearable context.

20/30/50cm Shooting Star Icicle Lights Multi Color Christmas Snowflake Show Bulb eBay

 
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Old 10-16-17, 03:09 PM
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Welcome to the forums.

If you are using the ones you linked to...... they require 5.5vdc to operate. You could run them off a 6 volt battery. How long do you need them to run for ?

I'm envisioning a 6v lead acid chargeable battery.
 
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Old 10-16-17, 03:20 PM
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six hours ideally? would that require multiple batteries? like this?

6V 5 Amp 6 Volt 5Ah Rechargeable Sealed Lead Acid Battery | eBay
 
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Old 10-16-17, 03:23 PM
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It may just require one and a charger. If you have the time...... order one and try it out. Of course, the larger the battery the longer the time but those batteries can get heavy quick.
 
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Old 10-16-17, 03:34 PM
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any tips on removing the ac wall plug and then wiring these lights to said battery? (noob)
 
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Old 10-16-17, 03:51 PM
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WIre cutters... But first look at the wire. Hopefully one conductor is a different color or the wire is somehow marked. If the wire is not marked with a permanent marker draw a line on one of the wires. Cut the wire so you have some of your mark on the transformer end and the lights end. Then with a volt meter you can plug in the transformer and check the wire to determine which wire is positive and negative. When hooking the lights up to your battery make sure you get the polarity correct. Some devices can be harmed if the polarity is reversed.
 
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Old 10-16-17, 04:03 PM
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what would be the best method to attach the wire leads to the acid battery?... solder is out because ill probably need to change to a fresh battery over the night
 
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Old 10-16-17, 04:07 PM
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Alligator clamps. Easy on and off.
 
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Old 10-16-17, 04:36 PM
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If the adapter is the one that is pictured.... the wiring is clear.
The copper colored side will be hot/+ and the silver side will be ground/-.
 
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Old 10-17-17, 11:46 AM
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also i know most batteries have acid but this ones actually named ACID battery.... its going to be safe to put near my head right?! LOL
Its for a music festival so there will be much movement.
 
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Old 10-17-17, 11:49 AM
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These are called SLA type batteries. (Sealed lead acid)
 
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Old 10-18-17, 09:09 AM
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Question

https://www.ebay.com/itm/6V-4Ah-SLA-...MAAOSw71BXPxv2
what are the benefits to the acid battery verses other 6v batteries? like this one?

https://www.ebay.com/itm/Ni-Cd-900mA....c100010.m2109
 
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Old 10-18-17, 09:29 AM
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If this is something you are going to be wearing on your head I would use lithium batteries. They are much lighter in weight than lead based batteries. A 2S (two cells in series) LiPo will be a bit high on voltage but might work or a 2S LiFe (lithium iron) battery will be much closer on voltage.
 
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Old 10-18-17, 10:39 AM
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would this work?
https://www.ebay.com/itm/ZIPPY-1100m...IAAOSwoydWpxEK

light requirements = [size=4]Power: Input AC 110 - 220V / Output 5V DC [/size]
[size=4]Power Consumption: Less than 5W/set[/size]
[size=4]LED working voltage: DC5V[/size]

and the bigger the mah the longer itll last?
 
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Old 10-18-17, 12:47 PM
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A battery like that will work. You will need more than one if wanting to power your lights for six hours. How long it will run or how much battery you need will depend heavily on how my lights you power.

One warning about getting any type lithium battery. You MUST have a charger that works with that specific battery chemistry!!! Most four button hobby chargers can charge LiFe but make sure before you buy one.
 
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Old 10-18-17, 03:37 PM
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dang i just realized ill need an on/off switch so the battery doesn't drain as soon as i solder the leads. any tips?
 
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Old 10-18-17, 04:04 PM
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I would solder a two pin connector onto your lights and the batteries. You just plug them together to turn it on and unplug to turn it off.

I use XT60 and XT90 but there are many others that will work.

 
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Old 10-18-17, 07:15 PM
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A really easy way to do this would be to use a AA battery holder. You can even get them with switches built in, like this:
https://www.amazon.com/Saim-Battery-.../dp/B00HR93NJM

Then you just need to buy lots of AA batteries. A new set of quality AA batteries will probably last most of the night. I do this all the time, but my lights run on 12V, so instead of using 4x AA batteries, I use 8x AA batteries (Each AA battery is 1.5 volts). The lights I use have a really high power draw, so I buy these Energizer Lithium batteries:
https://www.amazon.com/Energizer-Ult...dp/B004EFT2BU/
They are not rechargeable though. One set of these batteries should easily last you all night. The easiest way to find out is to test it. Just plug them in and turn your lights on when you go to bed. If they're still on and bright when you wake up the next day, you're golden.

The big bonus doing this is that if you can just stop at any store on the way to the event and buy fresh batteries. Other solutions will require you to remember to charge the batteries, and if you forget, you're SOL.
 

Last edited by az-guy; 10-18-17 at 07:17 PM. Reason: Added a line
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Old 11-08-17, 03:09 PM
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Smile

couldn't have done it without you guys!
 
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Old 11-08-17, 07:50 PM
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Awesome....... good job. Thanks for stopping back.
 
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Old 11-09-17, 09:22 PM
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Cool. It looks like you're using AA's. Have you found out how long a set will power the lights?
 
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Old 11-10-17, 12:11 PM
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It's a little late, but next time, you may consider a portable cellphone charger. They put out 5V which is probably sufficient to power these lights.

I think you may be able to remove some of the sticks to save power since each stick looks like a self contained unit.
 
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Old 11-21-17, 11:36 AM
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they lasted around 3 hours! and my other LED piece lasted all night!
 
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Old 11-21-17, 11:43 AM
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other led thing

the LEDs did a color shift all night and i didnt change the batteries once.
 
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