Shelf-Life

The shelf-life of a battery is the time assigned to a battery for it to be able sit unused with the assumption that it will still retain over 85% of its capacity when placed in service. For rechargeable batteries, this means that once it receives a charge it will reach 85% of its capacity. Shelf life begins on the manufacture date and is terminated on its inspection/test date, unless an extension is granted.

Batteries work through complex chemical reactions which release the energy needed to power your device. Unwanted side reactions also occur during the life of the battery degrading its overall ability to produce useful energy. Over time, these losses accumulate leaving the battery with significantly reduced capacity. Higher temperatures can often accelerate these unwanted reactions. To ensure a battery is always mission ready, a shelf life is assigned which is determined based on the chemistry of the battery and assumes that the battery is stored in temperate (moderate) conditions.

The first thing to understand is that shelf-life is not exactly the same thing as the expiration date on the milk in your fridge. Shelf-life only applies while a battery is in storage. The moment the battery is put in service it enters a period called service life.

For non-rechargeable batteries, this difference is negligible as once a battery is placed in service, it generally consumed within a short amount of time. Where a big difference occurs is rechargeable batteries. They should be placed on a charger before reaching their shelf-life date. At this point the battery has entered its service life and may continue to be used while it is serviceable. For optimal performance, it recommended that lithium ion batteries be replaced 4 years from date of manufacture.

Possibly, most batteries are assigned a Type II shelf code which means that the date can be extended. Shelf-life codes are based on a prediction of the condition the battery will in be after an extended period of time in storage. Like any prediction, however, individual results may vary. Very often, batteries are still in perfectly good condition after years in storage which is why they have an inspection/test date and not an expiration date.

Batteries must be tested to insure they meet original mission requirements.

For lithium ion rechargeable batteries the process is straight forward and can be performed locally. All you need is a charger which has the ability to indicate a faulty battery. (Do not attempt on batteries that have never received a maintenance charge, and are more than one year beyond their test/inspect date.)

1. Following the procedure in Tech Manual for the charger, attempt to charge the battery.
2. If the charger completes the charge cycle without any faults, proceed to step 5.
3. If the charger indicates a fault, remove the battery, clean the battery’s contacts, and attempt to charge a second time.
4. If the charger still indicates a fault, process the battery for disposal.
5. After the charger has completed its charge cycle, remove the battery and check the battery’s State of Charge Indicator (SOCI), if present. If the battery does not indicate 100% charge, process the battery for disposal.
6. If the charger completes its charge cycle and the battery’s SOCI (if present) indicates 100%, the battery has entered service life and may be used.

For non-rechargeable batteries, it is impossible to test each battery as they can only be used once. In this case, a representative sample needs to be tested.

1. Non-Rechargeable military batteries that have gone through verification testing at PSCOE (Power Sources Center of Excellence) typically have a 5 year shelf-life. The battery will expire 5 years from the date code (date of manufacture) printed on the identity marking of the battery. Look for a number in MM/YYW format where MM is the month, YY is the year, and W is a designation for the week in the month it was manufactured.
2. For large quantities of non-rechargeable batteries that have expired or are about to expire, please send an e-mail to the PSCOE mailbox usarmy.apg.cecom.mbx.ilsc-pe-pscoe-support@army.mil with your Point of Contact information stating you would like to enter the shelf-life extension testing program. Please include the following information and someone will get back to you shortly:
   • Battery name/nomenclature (for example BA-XXXX/U, etc.)
   • Battery NSN, if possible
   • Battery contract number
   • Battery manufacturer
   • Date code (manufacturing date on battery printed in MM/YYW format)
   • Quantity on hand (be clear as to whether you are reporting total number of packages or total number of batteries). If reporting packages, please indicate how many batteries per package.
3. Please note the PSCOE lab will charge a fee for each lot tested. Please take this into consideration as you weigh the cost of testing versus disposing and purchasing new batteries. Batteries used in shelf-life extension testing will be consumed.
4. The PSCOE lab will not test batteries for shelf-life extension that haven’t been stored properly (for example, in excessive heat/humidity). Please ensure your batteries have been properly stored in accordance with the item specification storage requirements. If you enter into the shelf-life extension program for testing you will be required to provide a signed statement attesting to proper storage.
5. The amount of batteries needed for testing varies depending on the lot size. As a general rule:
   • If your lot size is 16-150 batteries – 5 random samples will be needed for testing and consumed.
   • For 151-500 batteries – 8 random samples will be consumed in testing.
   • For 501-3,200 batteries – 13 random samples will be consumed in testing.
   • For 3,200-35,000 batteries – 20 random samples will be consumed in testing.
   • For over 35,000 batteries – 32 random samples will be consumed in testing.
6. Extensions up to 2 years can be granted depending on results. Keep in mind that the batteries may not meet extension testing requirements.
7. Feel free to add any additional questions to your inquiry email. PSCOE will evaluate each inquiry on a case by case basis and may work with unusual circumstances outside the normal standard operating procedure if necessary for mission function.

For more information, see the DoD Shelf-Life Management Program Manual at:
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/414027_vol1.PDF