# How much power/how many batteries would I need.

#### Joshwills230591

Joined Jan 24, 2021
5
Hi everyone hope everyone is doing well.

This probably sounds like an amateur question compared to some of the things asked on here. None the less hoping someone can help.

I need to work out the correct amount of rechargeable cells I will need to power something for at least 5-6h

I have 6m of LED strip power consumption is:
18w/m so 108w in total.
They are DC12 volt
Recommended power supply is 12v10amp for 5m.

my situation is i want to recycle a large 27000milliamp power bank and combine them to make a rechargeable led system. But I’m struggling to work out what determines what factors I.e watt and amp in turn working out of the power bank would be substantial. Or if I’m best building something my self.

#### jpanhalt

Joined Jan 18, 2008
11,087

#### Joshwills230591

Joined Jan 24, 2021
5
That will require a very large battery, if the values you gave are correct.

Given that the strip requires 108W at 12V = 9A Six hours would require a battery than can supply 54 Ah without being damaged. Here is one such example: https://dakotalithium.com/product/dakota-lithium-12v-54ah-deep-cycle-lifepo4-trolling-motor-battery/ Of course, lead-acid batteries of the same capacity are probably cheaper. In practice, you probably want a larger battery.
Thanks a lot for the message here is the link to the LED strips. I think my numbers are right but that battery doesn’t seem right. Or maybe they are just high consumption leds.

so that’s 108 divided by 12 gives 9amp per hour.

BTF-LIGHTING 5050 RGBW RGB+Cool White(6000K-7000K) 4 Colors in 1 LED 5m 16.4ft 60LEDs/m Multi-Colored LED Tape Lights IP30 Non-Waterproof Black PCB DC12V for Bedroom Kitchen Home Decoration https://www.amazon.co.uk/dp/B07G4C1T39/ref=cm_sw_r_cp_api_fabc_RuxdGbCX7V7ZV

#### jpanhalt

Joined Jan 18, 2008
11,087
Your numbers seem right. The listing says 0.3W per LED and 300 LED's per 5 m = 90W total. Six meters of them = 360 LED's = 108 watts.

For comparison, this past Summer, I installed 6, 8-ft LED stirps in the ceiling of a barn. Total LED wattage was 480W (80W for each for 8' lamp). The lit area is about 40' x 40' (1600 ft^2), and it is easily enough light to work in comfortably. They replaced 12, 80W fluorescent tubes.

#### crutschow

Joined Mar 14, 2008
32,899
so that’s 108 divided by 12 gives 9amp per hour.
108W divided by 12V gives a 9A draw.
Multiplying that by 6 hours gives the required battery capacity of 54Ah.

The cheapest solution would be a deep-cycle type (not vehicle) lead-acid battery with at least a 68Ah capacity such as this.
You should add a timer so you don't discharge the battery more than about 80% of its capacity.

How you going to charge the battery?

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#### Joshwills230591

Joined Jan 24, 2021
5
I think your numbers are correct. All colors on at full brightness consumes 0.4W per LED. If you want that for 6 hours, you need a big battery as already shown. A car’s headlights consume a similar amperage. Leaving them on for 6 hours would drain and possibly damage most car batteries.

https://www.amazon.com/Battery-Trol...ttery&qid=1611497428&sprefix=deep+cyc&sr=8-14
Thanks for the input, if we forgot about the amount of time I initially wanted Is there a type of cell I can combine in a certain way multiple to create what I need for a usable amount of time.

these are the shape batteries I’m hoping to use end to end down a cylinder 4ft long.

https://www.fogstar.co.uk/collections/batteries/products/vapcell-5000mah-26650-battery

I’m trying to work out how a Astera lights have done this.

https://cvp.com/product/astera-ast-...M86-0wog9jZSl8NKjyKikKPFjxPpB4PcaAomXEALw_wcB

#### Joshwills230591

Joined Jan 24, 2021
5
Thanks for the input, if we forgot about the amount of time I initially wanted Is there a type of cell I can combine in a certain way multiple to create what I need for a usable amount of time.

these are the shape batteries I’m hoping to use end to end down a cylinder 4ft long.

https://www.fogstar.co.uk/collections/batteries/products/vapcell-5000mah-26650-battery

I’m trying to work out how a Astera lights have done this.

https://cvp.com/product/astera-ast-...M86-0wog9jZSl8NKjyKikKPFjxPpB4PcaAomXEALw_wcB
They have either really efficient LEDs or not many in there at all.

#### crutschow

Joined Mar 14, 2008
32,899
these are the shape batteries I’m hoping to use end to end down a cylinder 4ft long.
For 54Ah @ 12V you would need to use at least 81 of those.

#### BobTPH

Joined Jun 5, 2013
7,540
54 years x 12 = 648 WH

648 / 3.7 = 175 AH at 3.7V

175 / 5 = 35

So, with perfect efficiency, 35 of them would be enough. In reality, probably 40 would do.

Bob

#### wayneh

Joined Sep 9, 2010
17,405
I’m trying to work out how a Astera lights have done this.
28W total power. That helps. 955 lumens versus your's, which is not clear from the specs.

I believe they are quoting 18 lumens per chip, and you have 360 of them? The lumens per watt are in line but not identical.

There's also apples and oranges. When they quote "up to 20 hours" or whatever, I guarantee it's not with all colors at full blast. They assume some duty cycle less than 100%.

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#### Joshwills230591

Joined Jan 24, 2021
5
28W total power. That helps. 955 lumens versus your's, which is not clear from the specs.

I believe they are quoting 18 lumens per chip, and you have 360 of them? The lumens per watt are in line but not identical.

There's also apples and oranges. When they quote "up to 20 hours" or whatever, I guarantee it's not with all colors at full blast. They assume some duty cycle less than 100%.
Ye man I just read it all in depth running 48v etc it’s given a hell of a lot to think about.

If I was to rig 12-13 cells in series at 3.6v at a 5000ma capacity. Running time would be 28w ~ 48v = 0.58amp per hour roughly 7-8h usage time.

do you reckon that sound more feasible?.

tha ms a lot for the input.

#### crutschow

Joined Mar 14, 2008
32,899
Note that Li-ion batteries require a charger designed for that purpose.
You can't use a standard lead-acid battery charger.

#### Alec_t

Joined Sep 17, 2013
13,784
i want to recycle a large 27000milliamp power bank
What is the nominal voltage of the power bank?
Does it consist of Lithium-based cells or Lead-acid cells?
Even if the bank is nominally12V and its cells are genuinely 27Ah capacity and could all be used for your project it would provide only half the energy you want.

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#### wayneh

Joined Sep 9, 2010
17,405
Ye man I just read it all in depth running 48v etc it’s given a hell of a lot to think about.

If I was to rig 12-13 cells in series at 3.6v at a 5000ma capacity. Running time would be 28w ~ 48v = 0.58amp per hour roughly 7-8h usage time.

do you reckon that sound more feasible?.

tha ms a lot for the input.
The arrangement (series, parallel, whatever) only matters in matching up voltages. That doesn't affect the power/battery-capacity issue. Cutting down the load to 28W obviously makes a battery solution more feasible.

#### Sensacell

Joined Jun 19, 2012
3,257

#### Audioguru again

Joined Oct 21, 2019
6,155
First you said you will use a powerbank. Most are used to deliver 5VDC at up to 2A to charge a cell phone. Not 12V at 9A.
Later you said you will use little no-name-brand Vaping battery cells that exaggerate their mAh rating.

Why do you need such a high number of portable LEDs?