BU-810: What Everyone Should Know About Aftermarket Batteries

Learn what makes a battery unsafe and what the consumer can do.

In the search for low-cost batteries, consumers may inadvertently purchase counterfeit batteries that are unsafe. The battery label appears bona fide and the buyer often cannot distinguish between an original and a forged product. Mobile phone manufacturers are concerned about these products flooding the market and advise customers to only use approved brands; defiance could void the warranty. Manufacturers do not object to third-party suppliers as long as the aftermarket batteries are well built, safe and approved by a safety agency.

Consumers are not the only buyers leaning towards aftermarket batteries. Public safety, healthcare and other organizations also take advantage of economically priced replacement batteries. Industrial aftermarket batteries are normally prequalified and many perform well, but the quality can be less consistent than the brand-name product, and some packs are said to be underperforming. Aftermarket batteries are mostly used for non-critical applications because liability issues could counter any savings gained.

Caution also applies when purchasing aftermarket chargers. Some low-end units may not terminate the battery correctly and rely on the battery’s internal protection circuit to terminate the charge when the battery is full. Redundancy in charging is important as the protection circuit of a bona fide battery can be damaged. (See also BU-304b: Making Lithium-ion Safe.)

Aftermarket batteries may also have insufficient safety provisions and rely on the charger to terminate the charge. Marrying the two aftermarket partners could turn battery charging into an unwanted event. Accidents are bound to happen when connecting a mobile phone or e-cigarette to the 12-volt system of a vehicle with a faulty inverter. Personal injury and damage can be the results.

Some manufacturers of laptops, medical devices, e-bikes and others disallow aftermarket batteries by digitally locking the pack with a tamper-proof security code. This is done in part for safety reasons; it also secures for the manufacturer a future demand for batteries with good margins.

Last Updated 2016-03-07

*** Please Read Regarding Comments ***

Comments are intended for "commenting," an open discussion amongst site visitors. Battery University monitors the comments and understands the importance of expressing perspectives and opinions in a shared forum. However, all communication must be done with the use of appropriate language and the avoidance of spam and discrimination.

If you have a suggestion or would like to report an error, please use the "contact us" form or email us at: BatteryU@cadex.com.  We like to hear from you but we cannot answer all inquiries. We recommend posting your question in the comment sections for the Battery University Group (BUG) to share.

Or Jump To A Different Article

Basics You Should Know
The Battery and You
Batteries as Power Source

Comments (5)

On June 22, 2016 at 6:10pm
Will Janoschka wrote:

Makita BL1830, BL1840 li-ion battery packs.  Are the unbranded packs any good at all?  Why do the Makita Chargers refuse to recharge the genuine Mikita packs that are easy to recharge with an IMAX-B6?  Thanks! -will-

On June 19, 2017 at 1:17pm
georgios papamichael wrote:

Hello I have a question for you Up to how many voltages it can awaken a lithium battery 18650 There is some specific charger that can awaken the battery automatically; But inexpensive.

On January 8, 2018 at 5:25pm
Darnell wrote:

We use to be able to use cell phones by plugging into an outlet, no battery needed!
Is there a company that still makes that possible?

On April 22, 2018 at 3:15am
John wrote:

I must say, I haven’t always been impressed with original manufacture batteries either. Given that I have demonstrated the dangers of a failed lithium battery and the massive flash fire it can have. But for me the question has become with cell phones. If manufactures are raising capacity too much while shrinking and condensing the design to fit the phone case? This goes for notebooks too which are getting thinner and lighter but users want all day battery life.

On December 9, 2018 at 11:20am
Richard wrote:

I stored Energizer and Harbor Freight Tools branded AAA an AA alkaline batteries in a plastic tote and they were corroded within months. I was wondering why this occurred. Also in the plastic tote was a pack of pool shock (chlorine) and candle gel.
Could anything within the tote along with the batteries have caused the corrosion?