How to Store Batteries So They Last for Years

Last Updated: August 31, 2021

Battery technology has come a long way in recent years.  Some types of batteries can last for up to 20 years.

But there’s a catch: The batteries have to be stored properly or risk losing their charge, getting shorted, or having capacity permanently diminished.

This guide goes over everything you need to know about storing batteries, including shelf life and long-term battery storage for power outages or disaster preparedness.

Jump to: Instructions for Specific Types of Batteries

General Instructions for Storing Batteries

Regardless of what type you have, there are some general rules to follow for storing batteries.

Don’t Let Batteries Touch Each Other or Metal Objects

battery storage
Store batteries on their ends to prevent fire risk and maximize shelf life.

Got a bunch of batteries hanging out in a drawer?  This is a very bad way to store batteries because their ends can touch each other.  Or, there might be metal objects like paperclips or coins in the drawer.

If the batteries touch metal or each other, they could short.  This could result in FIRE, BURNS, or even an EXPLOSION.

This is no joke.  The London Fire Brigade even warns about it, saying they get called to 24 fires per week started by batteries, chargers, or cables.

Even if they don’t get hot, the metal could still affect the batteries’ polarity.  So keep them neatly organized so their ends don’t touch metal.

Beware of Fire Risk

battery case
Highly rated fireproof battery case on Amazon.

Batteries can explode in a fire, making a bad situation even worse.  I recommend getting a fireproof battery storage case.

This one (Amazon link) is also waterproof and holds up to 182 batteries.

It’s affordable and really worth it for keeping your batteries stored neatly.

Keep Batteries Cool

Heat is terrible for battery chemistry.  Generally, most batteries need to be kept around room temperature (50-70F).

It varies by battery type, but self-discharge rate generally doubles for every 18F increase in temperature.  In other words, the battery will drain faster even when not in use.

You might think that this doesn’t matter with rechargeables – you can just recharge them to regain the lost capacity, right?  Wrong.  Heat can permanently affect how much charge the battery is able to hold.

But Don’t Freeze or Refrigerate Batteries

Corroded batteries
Freezing batteries can cause corrosion.

Contrary to common belief, you should NOT store batteries in the freezer.  The condensation can cause the batteries to corrode and permanently ruin them.

Extreme cold also causes the electrons in the batteries to slow down, preventing them from getting excited and doing their job.  With some types of batteries, the cold can permanently shorten their lifespans.

If you live somewhere very warm, then it might be smart to refrigerate batteries.  However, it’s then important that you keep them in an anti-condensation (aka vapor proof) container.

Zipable Mylar bags (Amazon Link) are good for this, so long as you put the batteries in another layer so they don’t touch the Mylar.

Keep in Low-Humidity Area

In high humidity, condensation can build up inside the batteries and cause them to corrode.  Ideally, batteries should be kept at a humidity of around 50%. If you don’t have a low-humidity area in your home, then you might want to keep them in the fridge in an anti-condensation container.

Avoid Quick Charge

smart charger
Our favorite Smart charger.

This doesn’t have to do with battery storage, but it will affect battery lifespan.  Quick charge causes batteries to overheat, which can permanently damage them and reduce their capacity.

Unless you absolutely have to, stick to trickle charge.  A good quality smart charger will prevent overheating and overcharging.

We recommend the Opus BT charger. (Amazon Link)

Storage Instructions for Specific Types of Batteries

If you are unsure about the different types of batteries, read our guide to battery basics for beginners.

NiMH (Standard)

  • Maximum Shelf Life:  2-3 years
  • Charge Cycles: 500-1,000
  • Ideal Temperature: 40-60F
  • Charge Level for Storage: 40% or above
  • Recharge every 1-2 months

nimh standard

Standard NiMH batteries (as opposed to the newer LSD ones) aren’t designed to be stored for a long time.  They drain quickly even when not in use and, if allowed to drain too much, they will be permanently destroyed.  Here’s how to keep them working.

Recharge Every 1-2 Months

Standard NiMH batteries have an insanely high self-discharge rate, which means they drain even when sitting idle.

The numbers vary, but generally you can expect that a NiMH battery will lose 20% of its charge within 24 hours and 10% each month thereafter.  That means that within 8 months, the battery will be completely drained. At high temperatures, the battery will drain even faster.

Don’t Let NiHM Batteries Drain Completely

NiHM batteries don’t have memory like NiCad batteries do, so there’s no need to drain them completely before recharging.  In fact, you shouldn’t let them drain completely.

If the battery is allowed to drain too much, it can go past the recovery point.  This is why you need to recharge them every 1 to 2 months.  The more you use and recharge a NiMH battery, the longer it will last.

Store Charged

Some batteries (including NiMH LSB and Li-Ion) shouldn’t be stored when they are completely full.  They actually discharge faster when fully charged.  It’s unclear whether this applies to standard NiMH batteries or not.

However, because NiMH batteries discharge so quickly, they should never be stored while near empty because they could discharge beyond recovery point.

Keep Cool

NiMH batteries can withstand temperatures of -4F to 95F. However, it’s best to keep them cool (around 40-60F).  If the NiMH battery is stored at high temperatures, the rate at which self-discharge occurs will be accelerated.

How much? 

At 70F, they will lose up to 40% of their charge in a month! Additionally, the longer the storage period, the more the cell capacity decreases.

Use a Good Battery Charger

NiMH batteries are particularly sensitive to overcharge and overheating.  Prevent this from happening by investing in a good battery charger.  This will help you get the most lifespan out of the batteries.

Conditioning NiMH Batteries

Sometimes NIMH batteries can suffer from voltage depletion.  This occurs when older batteries have been charged many times and crystals start forming in them.  You can revive the batteries with a process called “conditioning.”  Some battery chargers will have a conditioning setting.

NiMH LSD Batteries

  • Maximum Shelf Life:  Up to 10 years
  • Charge Cycles: 500-2,000
  • Ideal Temperature: 40-60F
  • Charge Level for Storage: 40%

NiMH LSD (which stands for low self-discharge) are the newer alternative to standard NiMh batteries.  They don’t have the high self-discharge like stand NiMH batteries and are suitable for long-term storage. This is what we recommend for disaster prepping.

Store at 40% Charge

Some batteries have a weird behavior: if you store them while completely full, they start to self-discharge rapidly.  However, if they are stored while at 40%, they somehow know to “sleep” and their self-discharge slows down drastically.

This applies to NiMH LSD batteries.  When stored at 40%, they will retain 70% of their charge after 5 years.  If stored at 100%, they might go near dead within a year.

Choose Lower Capacity for More Life Cycles

Another weird feature of NiMH LSD batteries is that high-capacity ones get fewer cycles.  For example, a 2500mAh battery might get 500 charging cycles whereas a 2100mAh battery could get 2,100 cycles.

Li-Ion Batteries

  • Maximum Shelf Life:  2-3 years
  • Charge Cycles: 500-1,000
  • Ideal Temperature: 32-77F
  • Charge Level for Storage: 40%

li-ion battery

Lithium-ion batteries are great for electronics or devices with high energy requirements and that get used every day.  However, li-ion batteries are not suited for long-term storage.  They quickly lose their charges and can go beyond the recoverable level.

If you do need to store lithium-ion rechargeable batteries, make sure to follow these guidelines.

Don’t Let Charge Fall Below 20%

When the charge of a Li-ion battery falls below 20%, it can enter a sleep mode.  After entering this mode, it might never recover and be able to charge normally.

So, be sure to charge your li-ion batteries frequently.  If not in use, be sure to recharge frequently so the battery charge doesn’t drain too much from self-discharge.

Store at 40% Charge

Like with NiMH LSD batteries, li-ion batteries should be stored at 40% full.   If stored when empty, they can self-discharge beyond the point of recovery, meaning that they will be completely ruined.

On the flip side, you also shouldn’t store them completely full either. They actually self-discharge faster. When full. Some of this capacity will NOT be recoverable (meaning the battery will never get it’s full capacity back).

Recoverable Capacity of Li-Ion Batteries after 1 Month of Storage

Temperature40% Charge100% Charge
104F85% 65%

Store at Cool Temperatures

As with any battery, li-ion batteries should be stored at a cool temperature.  However, they can be very sensitive to heat.  As the table above shows, they will permanently lose some of their capacity when stored at high temperatures.

Likewise, higher temperatures increases the rate of discharge as shown in the table below.  Remember, if a li-ion battery gets completely drained, it can go past the point of recovery.

Self-Discharge Per Month at Various Temperatures

Temperature40% Charge100% Charge

Never Let Li-Ion Batteries Get above 140F

Li-ion batteries can EXPLODE or CATCH FIRE if store in high temperatures.  That means they should never be left in your car on hot days, nor in places like your garage.

Check Date When Buying Li-Ion Batteries

Even when stored properly, li-ion batteries only have a shelf life of around 2-3 years.  So, if you buy li-ion batteries that have been sitting around on the manufacturer’s shelf for a while, you have already lost some of the usable life.

Lithium Batteries (Including button cell batteries)

  • Maximum Shelf Life:  Up to 20 years
  • Ideal Temperature: 60F
  • Charge Level for Storage: 40%

lithium batteries

Lithium batteries aren’t rechargeable, but they have the benefit of a very low self-discharge rates of just 1-2% per year. After 15 years, they can retain 85% of their charge.  This makes them suitable for long-term storage, assuming that you store them properly.

Keep Cool

Even though lithium batteries can handle extreme temperatures well, high temperatures will still cause them to self-discharge faster.  Ideally, you should keep them at 60F or below.

Don’t Put in the Freezer

While keeping lithium batteries at very cold temperatures will in theory help them last longer, the benefit is negligible.  However, the risk of them getting wet or condensation is high.  So, it’s not worth it to put lithium batteries in the freezer.  If your home is very hot or humid, then refrigerate them in a vapor-proof container instead.

Buy from Reputable Sources

Lithium primary batteries are expensive, so you might be tempted to buy cheap lithium batteries from generic sellers (like those based in China).  The problem is that these batteries are often sub-par quality, are old, or were stored in hot warehouses.

It’s not worth it to buy cheap lithium batteries.  Make sure you are getting batteries that you can rely on. Only buy from reputable brands and sellers, being sure to check the manufacturing date when you purchase.

Alkaline Batteries

  • Maximum Shelf Life: 5-7 years
  • Ideal Temperature: 70F

alkaline battery

Are you still using alkaline batteries?  While they may be cheapest in the short term, alkaline batteries are a very poor choice.  They have a very short lifespan and end up costing a lot over the long run.

Alkaline batteries are also very sensitive, so you’ve got to take care to store them properly.  Here’s what to keep in mind:

Don’t Leave Them in Devices:

Leakage is a huge problem with alkaline batteries.  If you leave them in devices for a long time, the battery will leak (causing that crystal-like coating on everything). The leaked acid can short the device.

Keep At 70F

Alkaline batteries are very sensitive to heat.  Ideally, they should be kept at 70F.  At this temperature, they will lose about 2-3% of their charge per year. At 100F, they will lose about 25% of their charge each year.

NiCad Batteries

  • Maximum Shelf Life: 3-5 years
  • Ideal Temperature: 70F
  • Charge Level for Storage: Close to 0%

Ni cad battery

NiCad batteries are also going obsolete because of issues like their very high self-discharge rate and poor performance.  If you still have these, then be sure to follow these storage guidelines.

Never Short NiCad Batteries

You shouldn’t short any battery, but it can be particularly dangerous with NiCad batteries.  They contain toxic cadium inside them.  When the battery ends touch metal, the batteries can explode and send all that toxic material everywhere.

Higher Temperature Increases Self-Discharge

NiCad batteries already have a very high self-discharge rate of about 10% per month at around 70F.  If you increase the temperature even slightly, the discharge rate skyrockets.

Memory Effect – Empty before Recharging or Storing

NiCad batteries are the only rechargeables which still suffer from “memory effect.”  If you try to recharge them when they are half full, they will “remember” the previous discharge amount and wouldn’t give more than that.

You must discharge them completely before recharging.  It’s also recommended to empty them before storage.

Recharge Frequently – Not for Long-Term Storage

NiCad batteries can form crystals inside them when stored for a long period of time.  This permanently damages the batteries and they will have to be thrown away.

Because of this issue, NiCad batteries are not suitable for long-term storage.  If you want them to last their full lifespan, they need to be recharged and used frequently.

Leave a comment

  1. GODS! There’s about a billion things to know and split hairs about to use and store batteries, optimally. It’s not worth it. They should just price all batteries as low as possible so the user can afford to just take the quick and dirty approach instead of going nuts over all that stuff.


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