High-Performance Battery Contacts for Mobile Electronics

By Ajay Saini | April 29, 2025

PCB real estate is at a premium with most modern electronic devices. Battery connectors with reduced dimensions and innovative spring designs give designers of small electronics more flexibility.

When requiring a recharge is an unacceptable constraint for mobile electronics, replaceable battery packs are the only practical option. From cordless power tools to mobile phones to portable defibrillators, the ability to quickly, and reliably, swap an empty battery for a freshly charged one introduces a high level of convenience and trustworthiness to any product. However, removable batteries add significant overhead to the overall mechanical and electrical design efforts. Mechanically, the battery must be accessible and easy to replace while being sealed appropriately to the environment and secure during operation. Electrically, the battery must make a low resistance connection time and again without adding high cost or size.

Two important features that must be considered when evaluating a battery contact are the current to contact rating and mating durability. Gold-plated beryllium copper contacts achieve ultra-reliable, high integrity connections in harsh environments. As a result, products with these contacts have a contact rating of 3A (finer pitches have a 2A rating) and are rated for 5000 mating cycles.

In addition to the contact surface itself, the mechanical action of establishing the interface is worth considering. Traditional right-angle connectors seen in many products have contact geometries that rely on the battery pack being inserted at an angle and then rotated down into position.

The complete family of 9155 series connectors from Kyocera AVX, including the new 9155-900, are ultra reliable with robust gold-plated beryllium copper contacts to provide high integrity connections in harsh environments, with up to 15,000 mating operations.

This can result in users commonly damaging the contact by not applying the appropriate angle or force to the battery during insertion. KYOCERA AVX has innovated several contact geometries to alleviate these interference issues. For example, the vertical mate 9155-800 series enables vertical battery insertion due to a unique contact spring design. As shown in Figure 2, the mating surfaces of this contact can be connected at any angle without fear of damage.

This same contact series can be used for horizontal board-to-board connections just as well. The 9155-800 makes a reliable connection as two boards are linearly pressed against each other with a variable gap ranging from 0.1 mm to 1.10 mm.

Figure 1: Vertical mate 9155-800 battery contact

Figure 2: Vertical mate 9155-800 used horizontally for board-to-board connections

Pitch and configurability

Connector pitch is a complex feature to specify in any electrical connection. Regulatory requirements often stipulate minimum creepage and clearance constraints, while industrial design and consumer requirements often trend in the opposite direction of margin. Traditional battery contacts have long been successful using a prevailing pitch of 2.5 mm, center to center.

Read this application note in its entirety at KYOCERA AVX. Visit the company’s website to see more battery connector solutions.