Do battery returns need to be a million dollar problem?

  • Posted on: 23 April 2016
  • By: Isidor Buchmann
Recycled Batteries

With the move to lithium-ion, fewer cell phone batteries fail during the warranty period than with nickel-based chemistries. Lithium-ion is less temperamental and needs less customer preparation than nickel. Yet, the volume of returned batteries remains relatively high. 

A North American cellular provider with about 12 million subscribers receives roughly 70,000 warranty returns per month. Out of these returned handsets, 50% have mechanical failures; 30% are performance related issues; 15% have battery or charger related problems; and 5% have miscellaneous faults. 

Returned cell phone batteries 80-90% of the returned batteries have either no fault or can easily be restored with a battery analyzer. The batteries are warehoused for eventual service or recycling. Battery returns represent a million-dollar problem

There are many reasons for the battery failures.The battery may not have been properly formatted at the factory. Perhaps the packs remained on the shelf too long or the charger is not functioning properly. Incorrect customer preparation is also to blame. The true reason may never be known. To satisfy the customer and honor warranty obligations, stores provide a replacement battery, no questions asked. 

Most dealers are not equipped to handle the influx of returned merchandize. To claim credit, the dealer sends the goods to the manufacturer. Truckloads of "worthless" handsets and batteries are transported, only to be stockpiled in warehouses for eventual repair and recycling. The cost of exchange, time lost by retail staff, shipping and warehousing amounts to a multi-million dollar problem. 

On a recent visit to Europe, a Cadex staff member learned that a large phone manufacturer had received 17 tons of failed batteries in one year alone. The batteries were stockpiled in large barrels for recycling. He also discovered that 15,000 NiMH batteries were returned to the manufacturer within weeks after a new phone had been released. When spot-checking the failed batteries with a Cadex C7000 battery analyzer, most packs appeared to be operational. 

On another occasion it was learned that a total of 14,000 Li-ion batteries were returned to a North American mobile phone provider. Only 700 packs, or 5%, were found to be faulty. Ten random samples of these failed batteries were sent to Cadex for further testing. The Cadex lab reported that each of these failed packs had indeed a genuine fault. 

A European service center sent 40 advanced Li-ion Polymer batteries to Cadex for evaluation. These packs had failed in the field and were returned by customers. When servicing the batteries on a C7000 battery analyzer, 37 packs were restored to capacities above 80 percent and impedances below 180 milliohms. Among the three failed packs, one had a 21 percent capacity reading and two units exhibited electrical shorts. 

Phone manufacturers report that 80 to 90 percent of returned batteries can be restored with suitable battery analyzers. The remaining 10 to 20 percent, which do not easily recover with the basic service, can often be revived with extended programs. Only a small percentage of batteries returned under warranty exhibit non-correctable faults. 

Not all batteries and handsets under warranty fail due to manufacturer's defects. A Service Manager of a leading mobile phone manufacturer hinted that coffee submersion is a common cause of failure. The acid in the coffee manages to corrode the electrical conductors in the handset and the battery. Coffee submersion occurs when the user mistakes the phone cradle or charger for the coffee cup.

Refurbishing, a cost-effective exercise

In an effort to salvage returned batteries, some mobile phone manufacturers segregate battery packs according to purchase date. Packs returned within the thirty-day warranty period are marked type 'B'. The batteries are then consolidated and sent to a regional service center where they are serviced with Cadex brand battery analyzers. If the batteries are clean, (have no coffee residue) and regain a capacity of 80 percent or higher, the packs are relabeled and sold as a 'B' class product. Over 90 percent of these batteries are being reclaimed with this program. 

On the strength of this success, some battery-refurbishing houses have extended the service to include batteries that are up to one year old. Repairing these older packs yields a 40 to 70 percent restoration rate. Effectively run, battery-refurbishing centers manage to generate a profit. Equally importantly, battery-refurbishing programs reduce the environmental impact of battery disposal.
Not all manufacturers offer battery-refurbishing centers. If not available, a program is gaining popularity in which the battery is serviced at store level. When a customer returns a faulty battery, the pack goes no further than the store that sold the equipment. 

The customer service clerk checks the battery on site with approved test equipment. Many batteries can be restored at this stage. If the battery needs a warranty replacement, a service report is issued and sent to the manufacturer by fax or E-mail. After verifying the report, the manufacturer offers replacement batteries as part of the warranty replacement policy.
Warranty replacements can be streamlined by connecting the battery analyzers directly to the Internet. Here's how it works:

The manufacturer sends each participating store an appropriate number of replacement batteries. When a customer returns a faulty battery, the service personnel test the pack with the in-store analyzer. If restoration is unsuccessful, the analyzer e-mails a report to the manufacturer stating the nature of deficiency. Date of purchase, battery type, customer name and other information pertinent to the manufacturer are also included. The manufacturer verifies the claim and, if valid, issues an inventory adjustment against the spare batteries allocated to the store. When stock gets low, a re-stocking order is generated and additional batteries are sent out automatically, regardless of office hours, and time zones. Such a system requires minimal staff.

Besides lowering overhead costs, a fully integrated warranty replacement system provides the manufacturer with valuable information regarding the nature of battery failures. User patterns leading to battery failure can be evaluated by geographic region. For example, a temperature related failure might be more likely to occur in warm climates than in cool ones. Batteries with higher temperature resiliency can be allocated for these regions. Recurring problems can be identified quickly and corrective measures implemented within months rather than years.

Why was this not done before?

One of the most difficult problems in servicing batteries at store-level is lack of technical know-how by the customer service personnel. With the ever-increasing number of battery models, the task of identifying a battery type and setting the correct parameter is becoming more and more complex. Technology has not kept pace in supplying the battery industry with suitable test equipment that is both cost effective and practical. 

To bring battery testing within reach of the untrained user, battery analyzers must be simple to operate and allow easy interface with all major battery types. Setting the correct battery parameters should be clear and concise. Uncertainties that can lead to clerical errors must be minimized. 

The Batteryshop™ software by Cadex has been developed for the purpose of simplifying battery maintenance. 

The Batteryshop™ software by Cadex has been developed for the purpose of simplifying battery maintenance. Installed in a PC, the operator simply selects the desired battery from the database of over 2000 battery listings. A serial link programs the Cadex 7000 Series analyzers to the correct parameters with the click of the mouse. The user only needs to insert the battery into the appropriate battery adapter and everything else is done automatically.

Some batteries, such as those manufactured by Motorola, are equipped with bar code labels. In such a case, the user only needs to scan the bar code label and insert the battery into the analyzer. The correct settings are automatically assigned to the analyzer through the PC.

Not all battery packs come with the bar code identification. If not available, a label printer connected to the PC can generate the missing bar code. These labels may be attached to a separate sheet that is kept on the service counter. The bar code labels may also be attached next to an illustration of the battery. With such an aid, the clerk simply refers to the correct battery and scans the bar code label associated to the battery. Instead of fumbling with technical data, clerks can devote quality time to the customer.

Effective Customer Service, a win-win solution

Checking a battery and assessing its status is one thing - finding a solution and fixing the problem is another. Increasingly, customers and dealers alike are seeking an alternate solution to replacing the batteries under warranty. They want a quick-fix.

Fully automated test procedures are being developed that check the battery and apply a quick-prime program to wake up a sleeping battery. The program will last from a few minutes for easy wake-up calls to perhaps an hour or longer for the deep-sleepers. 

Batteries with minor deficiencies will be serviced while the customer enjoys a cup of coffee or browses through the store. If the battery has an electrical short or does not accept a charge, the likelihood of revitalizing the battery is slim. This pack is eliminated within seconds to clear the test equipment for other batteries. If a pack requires a complete service consisting of priming and reconditioning, the customer is asked to come back later. 

A complete battery service offers the best service. Such a program makes optimal use of the restorative abilities of a battery analyzer. A full service may take five to eight hours and can be applied overnight. Multi-bay analyzers that service several batteries at the same time increase the throughput. Such analyzers operate 24 hours without user intervention. 

A customer may not have time to wait for the outcome of a battery test. The prospect of having to buy a new battery is even less appealing. In such a case, a refurbished battery may be the answer. This pack can be drawn from a pool of restored batteries which the store has built up from previous returns. This activity could become a lucrative side business as customers begin to realize the cost saving potential, especially if the replacement battery is accompanied by a performance report. 


Customers have high expectations and demand quick turnaround when a handset fails. Manufacturers and service providers realize the urgency to streamline the procedure of returned items. The expensive and wasteful battery exchange policies still practiced by some organizations may no longer be possible in the future. Fierce competition and tight margins will entice manufacturers and service providers to invest in modern test equipment. 

The switch to low-maintenance lithium-based batteries and a general tightening of battery quality standards has reduced battery returns somewhat. A new study shows that battery related problems contribute 15 percent to the return of a modern handset. With 70,000 handsets being returned to one leading USA provider in a single month alone, 15 percent accounts to over 10,000 failed batteries. Having acquired modern battery analyzing equipment, this provider reports sharp cost reductions while improving customer service and enhancing overall customer satisfaction.


This article contains excerpts from the second edition book entitled Batteries in a Portable World — A Handbook on Rechargeable Batteries for Non-Engineers. In the book, Mr. Buchmann evaluates the battery in everyday use and explains their strengths and weaknesses in laymen’s terms. The 300-page book is available from Cadex Electronics Inc. through, tel. 604-231-7777 or most bookstores. For additional information on battery technology visit

About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Richmond (Vancouver) British Columbia, Canada. Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. The author of many articles and books on battery maintenance technology, Mr. Buchmann is a well-known speaker who has delivered technical papers and presentations at seminars and conferences around the world.

About the Company
Cadex Electronics Inc. is a world leader in the design and manufacture of advanced battery analyzers and chargers. Their award-winning products are used to prolong battery life in wireless communications, emergency services, mobile computing, avionics, biomedical, broadcasting and defense. Cadex products are sold in over 100 countries.