Batteries: shouting down the counterfeiters

mpd-1Besides their enormous economic impact, counterfeit and cheaply made batteries raise safety concerns. It is important to protect your supply chain integrity explains Memory Protection Devices’ president, Tom Blaha

In 2014, The US Department of Homeland Security reported seizing 23,140 shipments of counterfeit goods valued at over $1.2 billion. As customs inspectors lack the time and resources to inspect more than a small fraction of shipping containers, this was probably just the tip of the iceberg.

In fact, counterfeit batteries are everywhere, affecting the performance of millions of electronic devices worldwide. Besides having an enormous economic impact, counterfeit and cheaply made batteries continue to raise safety concerns, especially for lithium-ion batteries that pack considerable energy into a small space.

Hidden dangers

Battery OEMs need to protect their brand reputation against counterfeit or cheaply made batteries that cut corners on quality and safety in order to save pennies. A defective Li-ion cell, for example, can experience an internal short circuit that releases large amounts of heat, causing chemical reactions to accelerate and potentially leading to ‘thermal runaway’ where temperatures can abruptly soar to 1,000 / 1,500°F.

Li-ion batteries and packs require protective circuitry and pressure-relief venting to help prevent current drain, over-discharge and overcharging, all of which can be especially harmful to batteries, sensitive integrated circuits and other critical components. Another hard to detect problem is high cell resistance, which causes output voltage to drop when placed under load, causing the battery to heat up as additional current is drawn, thus creating added safety risks.

Alternatively, some counterfeit batteries can deliver less than half the capacity of genuine OEM products, causing the end device to fail far sooner than expected.

Spotting counterfeits

Some fake batteries are easily detectable via visual inspection, but others look quite real, making it hard to detect an imposter.

To protect the integrity of your supply chain, purchase batteries from reputable
sources and perform due diligence by insisting on documentation that tracks the product all the way back to the factory. Also, make a habit of retaining a few random samples from each lot against which to check future orders. Check incoming battery shipments to ensure that the product comes with manufacturer-branded packaging material, as even well disguised knock-off products are rarely as well packaged.

With battery packs, it is often possible to spot inferior knock-offs by inspecting the solder joints, wiring connections, circuit protection board and outer casing.

Testing variables

As a further precaution, test equipment can measure such variables as battery capacity and under-voltage cut-off under load. Conversely, if tests show that the cut-off voltage is too high, this could be a sign that the battery was manipulated to boost capacity, which reduces battery life expectancy. Another test can be conducted to see if the cell has been overcharged beyond its ‘full’ condition.

For example, Li-ion batteries typically used in cameras deliver 4.2V/cell, or 8.4V for a two-cell pack. If charged beyond that point, the lithium metal can separate from the graphite anode and shorten the battery’s life. If the plated lithium does not get deposited smoothly, it can potentially lead to thermal runaway.

Battery operating life will be reduced if the metal or chemical constituents are of low purity, if lesser agents are substituted, or if manufacturing tolerances are not being held. Unfortunately, these conditions are not easily detectable without fairly sophisticated long-term tests on relatively large samples of batteries using automated test equipment.

As a general rule, if someone is selling batteries or battery packs for far less than the cost of the genuine OEM product, then it is likely a fake or a very inferior product. Given the increased sophistication of counterfeit batteries, the safest choice is to source batteries directly from the OEM or through an authorized distributor.