I'm using a LED strip that is roughly 910mm. The LED strip is a OEM 12V LED strip, running at 5W per meter.

My project is a LED strip that is suppose to be powered by batteries, this is to be used in a scenario of lighting up products in a supermarket for promotional and seasonal items.

So long story short I need to find out how many batteries or which batteries are the most efficient into powering my 910mm long LED strip for at least if being ambitious 30 days or 14 days or at least 7 days.

The reason behind why we need to use batteries is for the portability of the rig as it's meant to be a temporary solution not a permanent fixed product solution. I've also thought about using LED strips that run at either 6V or 3V to prolong the life expectancy of the power drawn from the batteries, but I'm not sure if this would improve it drastically. Also out of all the batteries would you say using AA, AAA, D, 9V batteries which would be the most efficient to use in this case?

My initial question is how many batteries would I need to power a LED strip roughly 910 mm long to last lets say 30 days or 14 days or at least for 7 days?

If there are any more variables or question you need in order to answer my question please ask.


closed as unclear what you're asking by Chris Stratton, Elliot Alderson, Neil_UK, DoxyLover, Bimpelrekkie Aug 5 at 9:35

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    \$\begingroup\$ The rather obvious detail missing from your question is the power requirement (watts) or current requirement (amps) of the LED strip. Can you add a link (into your post - not in the comments) to the datasheet for the strips. \$\endgroup\$ – Transistor Aug 4 at 14:22
  • 1
    \$\begingroup\$ E=U x I x t. You have U and t and need I. \$\endgroup\$ – winny Aug 4 at 14:48
  • 2
    \$\begingroup\$ This idea will not be practical \$\endgroup\$ – Chris Stratton Aug 4 at 15:24
  • 2
    \$\begingroup\$ Average 60 led/meter LED strip is 7 Watts. For 30 days that means you need 5 kWh per meter. Or like 60 kg of lithium battery or 150 kg of sealed lead acid deep cycle battery, or 175-200 D cell alkalines. \$\endgroup\$ – Jeroen3 Aug 4 at 15:41
  • \$\begingroup\$ It makes no sense to power it for more than one day, you should recharge or swap during the day. \$\endgroup\$ – Harry Svensson Aug 4 at 23:32

The strip will require 0.910x5 = 4.55W. At 12V, that's 4.55/12 = 0.38A.

30 days is 720 hours. So you would need a 0.38x720 = 274Ah of batteries at 12V.

That's a pile of maybe 6 car batteries, or around 220 alkaline D cells.

  • \$\begingroup\$ OP said "running at 5W per meter.", he's so far not said anything about how many meters he's going to run it for. So your answer should be "per meter". \$\endgroup\$ – Harry Svensson Aug 5 at 8:56
  • 1
    \$\begingroup\$ @HarrySvensson the question says 910mm, and only ever refers to a strip, not several of them. \$\endgroup\$ – Simon B Aug 5 at 10:24

Not the answer you're looking for? Browse other questions tagged or ask your own question.