Tuesday, 20 January 2015

Lifespan and the Apple expectation

Apple has applied for a patent to build a docking station to charge devices like the iPhone and iPad, which will retract the connector when the "iDevice" is being removed, to prevent damage to both the dock and the item. 

By Neil Oliver 

The move illustrates a trend in the consumer IT environment for improved reliability and increased robustness. However, that trend has been evident in industry for decades. But it isn't necessarily a good thing for the two concepts to become intertwined.

The expectations we should have of a battery for a professional medical application, for instance, would - in a world where the battery or charger is optimised for performance - be very different to those we might have in a consumer environment.

For instance, a medical professional might see the embedded battery in an iPhone or an iPad and be impressed by the sleek, seamless design it provides. As a result, they may well expect the power source in their professional devices to also be embedded.

However, in a medical device, with a product life cycle of ten to fifteen years, an embedded battery would be impractical. Over that kind of lifespan, the battery would have to be replaced five or six times, which would be impractical and costly. In a consumer device like an iPhone, the entire product is likely to have been replaced before the battery fails.

Size requirements 
Just as the aesthetics of an embedded battery might seem attractive at first glance, attempting to reduce the size requirement of a battery by embedding it might also seem like a good idea. This would remove the need for battery housing, thus reducing the space requirement.

However, this can only really be a workable option in a disposable or very short lifespan medical device. In more typical applications, where the device costs tens of thousands of pounds and lasts for more than a decade, it isn't practical for the same reason. A removable, rechargeable battery is the only workable option from a cost and reliability perspective.

Battery lifespan
Battery lifespan can also be a radically different requirement depending on the medical application. In some instances, replacing the battery every year is fine and also what the user expects - from both a practical and financial perspective.

However, if a battery designed for a frequently used application is only capable of 300 cycles, which is to say 300 full charges and 300 full discharges, it would be unlikely to last for even one year. The feedback that most of our OEM partners receive from hospitals is that they expect the battery to last for two to three years.

Most phone batteries will have a lifespan of around 300 cycles. This means that, after a year or two, the user will need to replace the battery or the device. As a manufacturer of batteries for professional applications, it’s crucial to understand the expectation this creates; otherwise you can very easily expose your OEM partner to criticism from the end user. Normally this means advising the OEM to change the expectation of its user community, compromise the power budget in some way or adapt the device itself.

Often, in this situation it is the power budget and thus the battery’s lifetime that suffers. It’s very difficult for an OEM to double the size or weight of a device, to allow for a larger power source for instance, and a good battery manufacturer will understand that.

The irony is that because manufacturers focus on the most obvious demands from the end user, the actual needs of this end user may not get enough consideration. The organisation that has to change the battery every year, and pay for that change, may have been willing to suffer a slight increase in size, in exchange for improved functionality and reduced operating expenditure.

Once an end user such as a hospital, considers the realities of increased cost and maintenance, they may well be very happy for the device to lack the product design brilliance of an iPad, but provide lower maintenance and replacements costs.

Nevertheless, from a personal point of view, I will be the first person to snap up the new i-Device charging and docking station. Like many people in the electronics industry, I'm a technology fan and find both the patent and the product interesting. However, I won’t be changing my view regarding the needs of professional battery applications as a result.

Read more about Accutronics’ work in professional medical battery applications here.

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