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Ideal Energy/Battery Source for a Battery Powered Lamppost Answered

Hello everyone,

First time posting, so, thank you ahead of time for all your help!

Project:

I was tasked with creating an outdoor lamppost for an event at a campground (IE: no immediate electricity source). At first, it seemed quite simple, but, looking at the necessary requirements, it seems to be more complex than I thought.

Requirements:

I need to find a way to power a high-powered LED light bulb (ideally 12W equivalent) for 10 hours a day (for 3-4 nights - for a total of 30-40 hours) without immediate access to an electrical outlet. So, it would be around 20 watt hours a day.

This battery source needs to be able to be outdoors, and face rain/weather. There may be a tarp, tent to cover it.

I may have access to a generator to recharge my battery source at another location if need be.

I currently have a bright DC 12V light bulb that would be ideal for this project, but, I could also use a AC light bulb if need be.

Potential Solutions:

  1. Connected 6V Lantern Batteries: Connecting multiple lantern batteries together, and swapping them out on a daily basis. Walmart has a set of Rayovac Heavy-Duty Lantern Batteries for around $2.50 each.
    1. Pro:
      1. Connecting these batteries in parallel and series would give me the 20 ah, and 12v specs needed. \
      2. It would come out to around $15 a day.
      3. Would be easy to put in a large water-proof container and connect to the lamppost
    2. Cons:
      1. Bit wasteful - I'd burn through around 20 of these batteries, and would have to recycle/dispose of them
      2. Sealed? - Unsure if I could put them in a waterproof container. Do they need venting?
      3. Mid-range cost: Would come out to around $50-60 due to the number of batteries needed
  2. 12V Deep-Cycle 20Ah+ Battery: A simple 20ah+ deep-cycle battery would provide me the DC power needed on a daily basis. I would then detach it during the day, and bring it to the generator to charge.
    1. Pro:
      1. Cost - Relatively cheap, at around $50, this battery option would be affordable
      2. Set it and Forget It - No need to connect multiple batteries together. This would just be an easy wiring job.
    2. Con:
      1. Venting - Unsure if I could place this in a simple waterproof container outside. Does it need to vent? Or, would a AGM deep-cycle battery be ok in a vent-free container?
      2. Recharging - Unlike the lantern batteries, I would need to bring this to a generator on a daily basis to recharge. Not the end of the world though.

Ideas:

I am vacillating between both options. Ideally I would like to go with the deep-cycle battery, but I am quite concerned with the venting problem. I don't believe the 6V batteries need to vent, so they could be placed in a simple container.

Question(s):

  • Does one of these solutions stand out more to you as the better fit?
  • Are there other battery solutions that you think would work better?
  • Do I need to use a deep-cycle battery, or would something like this battery work?

Again, thank you ahead of time for any guidance you could provide!

Discussions

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Jack A Lopez
Jack A Lopez

1 year ago

For the price you found, around 50 USD, for a 20 ampere*hour, deep-cycle, lead-acid, battery, you could instead buy a, nominally 12 volt, lithium-ion battery pack, with a charger for it, plus a "fuel gauge" display, i.e. a built-in circuit that can show you the approximate fraction of stored energy remaining, plus protection circuit to disconnect the load if its cells have been drained too far.

This kind of 12 volt lithium-ion battery pack, is usually sold, described with the words, "power bank", and many of them are capable of enormous peak current, even capable of jump starting a car.

As an example, this page,

https://www.ebay.com/itm/12V-30000mAh-Car-Jump-Sta...


showed up at the top of the list when I asked eBay to show me, "power bank 12v mah"

I am guessing one of these, "power bank" style, battery packs would work just as well, or better, with a moderate sized load, like 1 A, over 10 to 20 hours. The quotes given for the ampere*hour capacity of these things is like, 20 A*h, or 30 A*h, typically.

Actually, I have one of these power-bank-car-starter gizmos. It is not the exact same one as the one I pointed to, on the example page, linked above, but it is similar. Mine also has output voltage selectable as {12, 16, or 19 VDC}. Also, I think the quoted capacity of mine was 18000 mA*h, or 18 A*h.

If you like, I could try setting up my power bank gizmo, for 12 VDC out, across a 1 A load, or a 12 ohm load, and then watch it to see if it will actually keep that load powered for 10 to 20 hours.