How to service cell phone batteries
(BU46)
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
charged before use. Perhaps the packs remained on the shelf too long or the charger
is not functioning correctly. Lack of battery understanding may also be to blame.
The true reason may never be known.
To satisfy the customer and honor
warranty obligations, the stores provide a replacement battery, no questions asked.
Competition makes it tough to do otherwise. The faulty batteries are then returned
to the manufacturer for replacement.
Phone manufacturers are aware that 80-90%
of the returned batteries have either no problem or can easily be restored with
a battery analyzer. The remaining 10-20% can often be revived by reactivating
the safety circuit with a boot program and by applying charge/discharge cycles.
Only a small percentage of batteries returned under warranty exhibit non-correctable
faults.
Not all batteries and handsets brought in for service fail due
to manufacturer's defects. Some batteries get damaged due to dropping and other
physical abuse. A Service Manager of a leading cell-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 accidentally mistakes the cup of coffee with the charger
or cradle.
To reduce the flow of warranty goods, some manufacturers began
charging $35US for no-fault returns. With the added cost, the dealers had no other
option than to continue accepting and replacing returns from fickle customers.
Warehouses started to fill with dead merchandise; and in 1997 a critical mass
was reached. The cost of exchange, lost time by retail staff, shipping, warehousing
and paying a subsidy for a replacement phone became a multi-million dollar problem.
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. Batteries that are clean, (have no coffee residue) and regain
a capacity of 80% or higher, are relabeled and sold at a discount price. The refurbishing
program reclaims over 90% of the returned batteries.
On the strength
of the 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 40-70% restoration rate. Managers have indicated that effectively run battery
refurbishing centers manage to generate a profit. Equally importantly is the environmental
benefit in restoring rather than disposing of a battery.
Storefront
battery service
Servicing a batteries at point-of-sale is becoming
a viable alternative to sending the pack to central service centers. With storefront
service, the pack goes no further than to the store that sold the product. The
batteries are tested, repackaged, and made ready for the next customer with a
battery problem. This eliminates courier charges and relieves the warranty obligation
by the manufacturers.
| Storefront
service offers a cost-effective solution to battery returns. Large
cellular provider estimate the cost of battery warranty returns at $US10 million
per year. According to service centers, 95% of these batteries can be restored
and reused. |
Modern
battery analyzers are equipped with rapid-test programs that assess the battery
state-of-health in a few minutes. Some analyzers (Cadex) offer a boost program
to wake up seemingly dead batteries because regular chargers can no longer recharge
these packs. The service takes only a few minutes.
How does a battery
fall asleep? A lithium-ion may become dysfunctional if discharged too deeply without
applying a recharge after use. The boost program applies a gentle charge current
to reactivate the battery's safety circuit. A fast-charge follows. To demonstrate
the effectiveness of boost, 27 of 92 returned lithium-ion batteries were permanently
restored with the boost function of a battery analyzer (Cadex C7400) at the Cadex
test laboratory.
If a pack requires a complete service of priming and
reconditioning, the customer is asked to come back later. Alternatively, a refurbished
battery can be given as a replacement. Only batteries with mechanical defects
or those with non-correctable electrical problems need replacement.
Connecting the battery to the analyzer has been a major challenge for customer
service staff. Setting the correct battery parameters and selecting a program
is another hurdle. If a store handles a limited number of phones or if trained
staff is not available, custom battery adapters are the answer. Custom adapters
are made for a specific battery type and allow easy insertion of the battery.
A wrong connection is not possible. Because of the firm contact provided between
battery and analyzer, the custom adapters produce the most accurate readings,
especially on rapid-testing. (Cadex offers the SnapLock custom adapters that automatically
configure the analyzer to the correct setting.)
Service technicians
dealing with a multitude of batteries may prefer a universal battery adapter.
This requires programming the battery analyzer to the correct battery chemistry,
voltage and milliampere rating. Once set, these parameters can be stored in those
adapters equipped with a memory chip. (The Cadex adapters hold up to 10 battery
configuration codes. If more storage is needed, a PC with BatteryShop software
will be required. With a PC, the user can program the analyzer by clicking the
mouse on the selected battery.)
Why
was storefront service not done earlier?
Point-of-sale service has
only become feasible with modern, easy-to-use battery analyzers. Older units were
designed for trained technicians and engineers. The programs consisted of cycling
to remove the 'memory' on nickel-based batteries. Lithium-ion no longer suffers
from memory and cycling has little effect in improving this battery chemistry.
Today, customers want fast service and are not prepared to wait for long
service procedures. Neither can the equipment be tied up for any length of time.
One of the key features of the modern battery analyzer is the ability to assess
the battery quickly and apply the needed repairs in minutes rather than hours.
Offering battery test service at storefronts improves customer service and
enhances overall customer satisfaction. Organizations using modern battery analyzers
have reported sharp reductions in service related expenses. Manufacturers support
storefront service and often furnish the participating dealers with battery analyzers
of choice. This trend is growing. With camera phones and increasing use of data
transmissions, the battery is becoming a critical part in the overall performance
of a cell phone.
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Created: March 2003, Last edited:February
2004