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So I am gathering information on what I need to bring together to create a solar powered LED based lighting system for my shed. I need a battery, a charger controller for the battery, solar panel and LED light strip. The battery must have sufficient capacity to power the entire length of the LED strip, and 20% more than that.

I am stuck on the battery. There are lithium batteries which are quite expensive. There are lead acid batteries as well that sound a bit dangerous (the acid part). Then there is also a term "deep cycle" that is applied to some batteries. My primary concern is, what specific battery type is most suitable to work across temperature range -10degC to +40degC and also will not deterioriate and possibly explode or catch fire as it is charged and discharged many times in this temperature range?

The battery will only power LEDs so I do not need an inverter. I have so far not found a battery for use in shed. There are a lot of different battery types and I am not sure what to use.

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    Do you consider the battery in your car "dangerous"? The term is wildly subjective. Any battery has risk associated with it.
    – isherwood
    Feb 6, 2023 at 20:18
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    Lead acid is your basic car starting battery. Deep cycle is lead acid also but made for long discharge, like on boat powering a trolling motor. Usually the prefer type for solar charging. Most batteries do not like cold and their amount of power is reduced, but for just LEDs should not matter as much.
    – crip659
    Feb 6, 2023 at 20:29
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    So why not put the batteries in the ground below the shed? That will limit the extremes of temperature...
    – Solar Mike
    Feb 6, 2023 at 20:45
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    "The battery must have sufficient capacity to power the entire length of the LED strip"... for how long? How big is the LED strip?
    – spuck
    Feb 6, 2023 at 20:52
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    @Quantum0xE7 "I am not sure what can happen to it when it sits at 40degC in summer for many weeks and then subzero temperature in winter for many weeks." So the exact conditions these batteries experience in 100s of millions of cars every year?
    – Glen Yates
    Feb 6, 2023 at 21:08

4 Answers 4

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There are lead acid batteries as well that sound a bit dangerous (the acid part).

As long as you don't pop the cork on the battery and pour the acid on yourself (or drink it) it'll be fine. It's best to store them right way up. Lead acid batteries are extremely safe. The only way to have an accident is to not use a charge controller then overcharge them a lot, which will electrolyze the water and release hydrogen, which is an explosive gas. The other risk is fire caused by short circuits that melt wires, but that's not specific to this type of batteries. At least, a lead acid battery will just melt your wires, whereas a LiPo will melt your wires then and explode.

In your use case the problem is temperature. Lead acid will lose a bit of capacity when cold, and recover it when warm.

Lithium works better when cold for discharging, but it's really not recommended to charge Lithium batteries below 0°C because freezing temperature reduce ion mobility in the electrolyte so it'll form tiny solid lithium spikes which will end up shorting it internally. So the protection circuit usually disables charging below 0°C, which means in your case, with an unheated shed, it won't work.

Since your shed is exposed to the same conditions as a RV, I'd recommend looking into what people who own RV's use. You'll probably end up with a deep cycle lead acid battery, a few solar panels, and a charge controller.

Discharging a lead acid battery too deep will kill it, even once. Cutoff voltage depends on temperature, so you need a cutoff that will turn off the loads when required. This is usually a feature of the solar charger.

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    Not only do deep cycle lead acid batteries excel in a situation exactly like what the OP is looking for, they are a mature, therefore inexpensive solution. Batteries, controllers, etc are readily available and have been on the market for decades. Development costs have long been recouped and pricing is easy. They're not cutting edge sexy like LiOn or LiPo, but they're not spendy like them, either.
    – FreeMan
    Feb 7, 2023 at 18:12
  • Yes, it's the best solution for OP, it just works, very forgiving, doesn't explode... just got to be careful about over-discharge, but that's the electronics' job.
    – bobflux
    Feb 7, 2023 at 20:31
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A lead-acid battery's acid is not dangerous when using a charger or charge controller designed for lead-acid, and the battery is installed in an enclosure. They sell marine battery boxes for this purpose that are not expensive. They're just plastic. Chargers and charge controllers designed for lead-acid are legion - almost every one supports lead-acid. Much is available at retail, 24x7, at "travel centers" (truck stops) like Love's or Pilot/Flying J.

The downside to lead-acid is you must use it only in the 70-100% range (meaning only using 30% of its nameplate capacity) if you want to get the full 4-7 year life out of the battery. Dipping any deeper shortens battery life - yes, this is terrible, they are terrible batteries but they are so cheap nobody cares about their deficiencies LOL. This paragraph is talking about "Deep Cycle" lead-acid batteries. Most lead-acid batteries are optimized for engine starting and immediate recharge - they degrade rapidly in a deep cycle application.


As lithium batteries get scaled up into billion-unit production, they are actually becoming cheaper per USABLE watt-hour than lead-acid. (given that you can realistically use about 80% of a lithium's nameplate range instead of 30% lol). However that only applies to raw batteries. When you buy a retail product ("portable power station" or "solar generator"), they really rip you off, bigtime. Probably because of the huge return rate from angry customers who actually believed their marketing claims LOL.

However, raw lithium batteries, while affordable per usable watt, are difficult to work with. You are responsible for implementing three systems: a cell equalizer, a BMS to protect the battery from overcharge or over-discharge or cold-charge that would make it catch fire, and a solar charge controller that understands lithium. If you don't get that stuff right, the battery can catch on fire. Also, there are complications with charging the battery below 0°C.

Worth it? Depends on the size of the pack I suppose. You really need to learn more about how to think about battery sizing. You're on the right track but keep skilling up. Skills last a lifetime, and a lot of stuff is happening in battery tech. You'll use it.

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  • What about "deep cycle" batteries, can't they be used across the full capacity without deteriorating the battery itself?
    – gyuunyuu
    Feb 8, 2023 at 22:21
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I don't think we could realistically help select a battery type based on the criteria of your specific installation. An attempt to do so would likely render this a "shopping question" and be considered off-topic.

The best answer I can think of is to refer you to a resource such as Battery University where you can learn more about the characteristics, engineering trade-offs, and recommended use & care for various types.

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  • I just need to know if there is specific kind of battery that must be used in the shed in this application while being charged via solar panel. Also, is it safe to use lead acid batteries in this case? I cannot say.
    – gyuunyuu
    Feb 6, 2023 at 20:45
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I am doing something similar, I used A lead acid deep discharge batteries which work fine for me. There is a catch with lead acid batteries, they have a fairly steep discharge curve. The lead acid battery will start at about 13 volts at the terminal; the voltage will slowly drop as it discharges. If you use a SEPIC (Buck Boost combined) converter it will maintain the voltage until the battery dies. You need to know what the LEDs will require current wise. The ones I used are about 1.5 amps per meter. I have other that are just short of 3 amp per meter. They are on china 30 amp dimmers. They work up to 22 amps no problems they work good. If it is not to late consider using 24 volt LED strips, that will save a lot on the wire. Use this search term " LED Bar Light Aluminum Rigid Strip". I purchased them from my favorite china supplier in 1 meter length. They mount with clips.

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