The development of the credit card sized battery
If someone described an object as being as small as a sugar cube, you would instinctively understand the comparison. However, if a design engineer described it as being the size of a 1ICP-06/34/50-2 Lithium-Ion smart battery, most people would be puzzled. It is for this reason that Accutronics dubbed its compact smart battery the ‘credit card battery’. Here, Neil Oliver, Technical Marketing Manager at Accutronics discusses the creative process of bringing an original energy solution to the medical market.
Many original equipment manufacturers (OEMs) want to be able to integrate a battery that suits their application without going through the time and expense of developing a new energy solution for every product. However, finding a product that meets their quality expectations and that comes with the right level of functionality and regulatory compliance is no mean feat.
It was to meet this demand that the range of credit card batteries was born. The series has been designed as a standard, readily available product, which lends itself to customisation in a timely and cost effective manner. The credit card sized batteries are pre-engineered, tooled and qualified before they reach the end user.
The rationale for developing the new range of smart batteries came from the fact that medical device OEMs find it difficult to access smaller, high quality rechargeable lithium-ion battery packs for portable devices, such as nebulisers or infusion pumps and wearable devices like endoscopy recorders or blood pressure and glucose monitors.
This might seem surprising, given the success of lithium-ion batteries in consumer electronic devices such as mobile phones and laptops. However, the requirements of OEMs in the medical market are very different from those in the consumer sector. This often leads to a disconnect between managing expectations and what the battery industry is willing or able to provide.
For instance, the lifecycle of an average consumer battery is 18 months. In contrast, medical devices have a lifespan of 15 or more years, which makes the risk of obsolescence very high. This means that embedding a consumer battery, which will become obsolete in just a couple of years, is not a viable solution for medical device manufacturers.
Regardless, OEMs often have to buy a battery that was designed for a mobile phone or portable camcorder. However, such products don't come with the technical backup required and the OEM is at the mercy of the product life cycle of the consumer device for which the battery was originally intended.
In contrast, the credit card battery is suitable for the long life cycle and demanding performance of medical equipment. The products feature accurate impedance tracking fuel gauges, an active protection system and a compact connector.
Available in two variants, the CC2300 and CC3800, the batteries measure just 85.6mm x 54.0mm and have exactly the same footprint as a regular credit card. Despite this compact design, both batteries feature lithium-ion cell technology for a long runtime and fast charge capability. Each of these batteries operates from 4.2V down to 3.0V (3.7V average) and has a typical capacity of 2300mAh or 3800mAh respectively.
The smart credit card sized batteries are unique, not only due to their physical size, but because of the technology employed. Designed with flexibility in mind, they offer freedom of choice to medical OEMs, in the same way that credit cards and other financial products offer freedom of choice. And just like a sugar cube, the name of the battery clearly describes the technology encapsulated in such a small piece of engineering real estate.