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Topic: what kind of battery for 5V 5A output? (Read 4470 times) previous topic - next topic

Noobian

#15
Dec 25, 2015, 04:10 pm Last Edit: Dec 25, 2015, 04:40 pm by Noobian
Ok I think liFePO4 battery is a good start.
My problem is that I tought I could drop the 6.4V (2*3.2 battery) to 5V with a LM7805 ^^ but I've read the data sheet and I've seen that it can output a maximum of 1A :o

LM7805 is used only for very low power consuming devices.  There are buck converters like XL4005 which has 5A I guess, but probably needs a heat sink.
If you go with 5v strips in series, you need only half amperage , or maybe go with low amperage strip like a 12v one, that would eliminate the need for high current and will generate less loss due to heat I guess. So imo, I will consider higher voltage and lesser amps as a better choice. 

If you wire 2 x 5v strips in parallel, you need 5 volts * 4.4 Amps ( 22 watts for 2x0.9m)
If you wire 2 x 5v strips in series,   you need 10 volts * 2.2 Amps (22 Watts for 2x0.9m )

If you wire 2 x 12v strips in parallel, it consumes only 1.8 Amps (22 watts for 2x0.9m) :smiley-cool:

You don't have to use a step down if you wire the strips in series to use 10 volts. 3x26430 batteries would give 9.6 volts. Also by wiring the strips in series your amperage won't double.

Another option is to use 12v strips in parallel. You could use 3x Li-ion batteries in series and get anywhere between (min 11.1 volts to max 12.6 volts). The advantage of 12v strips is that they need only less than half the amps of a 5v strip.


I watched the video, the guy mentions those strips work even with little lower voltages, so I don't think you need any converters.

Zapro

You don't have to use a step down if you wire the strips in series to use 10 volts. 3x26430 batteries would give 9.6 volts. Also by wiring the strips in series your amperage won't double. :) 
No, just no.

You cannot hook two strips in series, because:

1) They are not constant resistance - one strip will get fried while the other will get too low a voltage when they are not displaying the same content.

2) You will offset the data-connection of the second strip by +5V - this is absolutely a no-go.

// Per.

Noobian

No, just no.

You cannot hook two strips in series, because:

1) They are not constant resistance - one strip will get fried while the other will get too low a voltage when they are not displaying the same content.

2) You will offset the data-connection of the second strip by +5V - this is absolutely a no-go.

// Per.
That's funny, I thought these strips were designed to be connected in daisy chains.

Well, I searched these other forums and here's what they show.
http://electronics.stackexchange.com/questions/122724/12v-led-strips-in-series-with-a-24v-power-supply
http://www.candlepowerforums.com/vb/showthread.php?401857-Wiring-LED-strips-in-series
http://www.theuncommonlaw.ca/blog/diy-how-to-wire-led-strip-lights
http://www.rcgroups.com/forums/showthread.php?t=1649856


Zapro

That's funny, I thought these strips were designed to be connected in daisy chains.

Well, I searched these other forums and here's what they show.
http://electronics.stackexchange.com/questions/122724/12v-led-strips-in-series-with-a-24v-power-supply
http://www.candlepowerforums.com/vb/showthread.php?401857-Wiring-LED-strips-in-series
http://www.theuncommonlaw.ca/blog/diy-how-to-wire-led-strip-lights
http://www.rcgroups.com/forums/showthread.php?t=1649856
Why on earth is it that you are so damn ignorant? Why not reading what other people is posting.

OP is using WS2812 LED's. They are intelligent, powered by 5V, has a DATA in, and DATA-out.

http://3.bp.blogspot.com/-J33RF-HsmWk/UqHEvbOy1kI/AAAAAAAAAO4/3-XGi2HcA80/s1600/Esquema-Arbol-de-Navidad-Shield-Arduino.jpg

// Per.


Noobian

Why on earth is it that you are so damn ignorant? Why not reading what other people is posting.

OP is using WS2812 LED's. They are intelligent, powered by 5V, has a DATA in, and DATA-out.

http://3.bp.blogspot.com/-J33RF-HsmWk/UqHEvbOy1kI/AAAAAAAAAO4/3-XGi2HcA80/s1600/Esquema-Arbol-de-Navidad-Shield-Arduino.jpg

// Per.


Here they says it is possible to daisy chain WS2812 LED's
http://mjhdesigns.com/?p=312

besides, I had asked OP whether he could change his choice in led strips since his only use with the
strip is to light up his saber in blue.

Zapro

Here they says it is possible to daisy chain WS2812 LED's
http://mjhdesigns.com/?p=312

besides, I had asked OP whether he could change his choice in led strips since his only use with the
strip is to light up his saber in blue.
They need to be daisy chained to work - alas their data in/out needs to be daisy chained.

You cannot daisy-chain the supply voltage for these which is what you suggested to OP.

// Per.

bodtx

Indeed Zapro is right you cannotchange the input current for theese strip with a different wiring. so The voltage remains 5V and the Amp is mutltiplied by the number of the leds.
Chaining here http://mjhdesigns.com/?p=312 meens extend the strip with another, input must be 5V and Amp will grow up.

bodtx

Moreover, Do I need an Overvoltage protection when usind Ni-mh batteries? I know that they can deliver up to 1.4V at the begining

zoomkat

Google forum search: Use Google Search box in upper right side of this page.
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terrablast

Hi,

            Any final outcome for this problem ? how to power 288 leds with battery ?

Regards,
Raymond

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