The document discusses key considerations for designing lithium-ion batteries for portable devices. It emphasizes that specifications are important to outline physical, environmental, and performance requirements upfront to guide development. Physical constraints, operating ranges, safety systems, and smart battery capabilities that provide information to devices affect costs. A good specification treats the battery design like a blueprint and ensures all necessary factors are addressed to reduce risks.

1. Manufacturing That Eliminates Risk & Improves Reliability
Design Considerations for Lithium
Batteries Used in Portable Devices
09.26.2019

2. Manufacturing That Eliminates Risk & Improves Reliability
2
Agenda
 What goes into a specification that can be easily turned into a product.
 Understanding how the physical and environmental requirements
affect the design.
 Cover the major cost drivers of a final battery to power a device.
 Safety Systems used to protect the battery pack during operation and
charging.
 Smart Batteries – what are they and what does this really mean?

3. Manufacturing That Eliminates Risk & Improves Reliability
3
Creating a Specification

4. Manufacturing That Eliminates Risk & Improves Reliability
4
Importance of a Specification
 A specification is necessary. It
would be like building a house
without building plans.
– Project failure and cost overruns
happen without it
 Upfront requirements and
performance specs are outlined
early at the start of each project.
– It is an investment with great
return.

5. Manufacturing That Eliminates Risk & Improves Reliability
5
Importance of a Specification
 A specification provides a full
understanding of the requirements
upfront before development begins.
– Provides clear and concise direction
– Opens dialog with the customer on options
available
– Reduces wasted time and cost in changes
– No surprises at the end of the project.
 Helps with product integration,
interface, and handshaking
requirements.
– It goes beyond just the battery.
– Seamless integration

6. Manufacturing That Eliminates Risk & Improves Reliability
6
Importance of a Specification
 Physical and electrical interface and environmental aspects must be
defined.
– Needed for proper cell selection
– Additional electronics defined, if required.
– Electrical and physical protection.

7. Manufacturing That Eliminates Risk & Improves Reliability
7
Physical and Environmental Requirements

8. Manufacturing That Eliminates Risk & Improves Reliability
8
Physical and Environmental
 There are many factors of how the physical and environmental
requirements affect the design.
– How big or small is the battery?
– Is it required to deliver power or energy or both?
– Is it even possible to design a battery solution to meet the requirements?

9. Manufacturing That Eliminates Risk & Improves Reliability
9
Physical and Environmental
 What are the high and low operating ranges?
– Do these exceed today’s battery technologies?
– What can be done if they do?

10. Manufacturing That Eliminates Risk & Improves Reliability
10
Cost Drivers

11. Manufacturing That Eliminates Risk & Improves Reliability
11
Cost Drivers
 Basic cells that go into a battery are normally inexpensive, so what
makes some batteries more expensive than others?

12. Manufacturing That Eliminates Risk & Improves Reliability
12
Cost Drivers
 Chemistry and number of cells.
– What protections are required?
– Quality of the cells:
• Tier 1 cells
• Tier 2 cells
– The power and energy rating
of the cells.

13. Manufacturing That Eliminates Risk & Improves Reliability
13
Cost Drivers
 Physical geometry of the cells and how they sit within the battery.
– Plastic enclosure or heat shrink?
– What are the drop requirements?
– Does the design need IP67 rating?

14. Manufacturing That Eliminates Risk & Improves Reliability
14
Cost Drivers
 Does the battery have electronics enclosed within?
– Fuel gauging
– Integrated charger within the battery
– Customer electronics in the battery
– High-power / high-current
connector needed
– Built-in inrush protection
– Built-in fan

15. Manufacturing That Eliminates Risk & Improves Reliability
15
Safety and Protection

16. Manufacturing That Eliminates Risk & Improves Reliability
16
Safety and Protection
 All chemistries require protection
to some degree.
 All chemistries can overheat
when shorted,
– Overcurrent protection is
required.
 All chemistries can overheat
when overcharged.
– Over temperature and/or
overvoltage protection is
needed.

17. Manufacturing That Eliminates Risk & Improves Reliability
17
Safety and Protection
 Li-Ion based chemistries require more protection than others.
– Protection from overheating
• Heat prevention
• Heat dissipation
– Protection from reduced cycle life
• Undervoltage protection
– Protection charging and discharging outside of
allowable parameters
• Voltage / Current / Temperature
– Secondary protection
• Medical and IT

18. Manufacturing That Eliminates Risk & Improves Reliability
18
Smart Batteries

19. Manufacturing That Eliminates Risk & Improves Reliability
19
Smart Batteries
 A Smart Battery Pack is a battery capable of providing information
about its operating parameters to the outside world.
– These parameters can include:
• Charge level
• Battery voltage
• Cell voltage
• Charge and discharge currents
• Battery temperature
• State of health
• Remaining run time
• Remaining charge time
• And many more

20. Manufacturing That Eliminates Risk & Improves Reliability
20
Smart Batteries
 The most common method of conveying the information to the host
system is through:
– I2C
– SMBus
– Single wire communication

21. Manufacturing That Eliminates Risk & Improves Reliability
21
Smart Batteries
 A smart battery can also be a battery with additional circuitry added
that it controls:
– Built-in charger with various topologies
– Customer electronics
– Built-in fan
– Integrated Heater

22. Manufacturing That Eliminates Risk & Improves Reliability
22
Summary

23. Manufacturing That Eliminates Risk & Improves Reliability
23
Summary
 Treat your specification like a blueprint.
 Know your physical and environmental requirements.
 Understand what the major cost drivers are.
 Know what safety systems need to be in place.
 What operating parameters need to be provided to the outside world.
 Additional built-in electronics increase cost.

24. Manufacturing That Eliminates Risk & Improves Reliability
24
Our Products
Battery Packs Flex & Rigid-Flex PCBs Cable Assemblies Printed Circuit Boards
RF Products User Interfaces Flexible Heaters EC Fans & Motors

25. Manufacturing That Eliminates Risk & Improves Reliability
25
Q&A
 Questions?
– Enter any questions you may have
in the control panel
– If we don’t have time to get to it, we
will reply via email

26. Manufacturing That Eliminates Risk & Improves Reliability
26
Thank You
Check out our website at www.epectec.com.
For more information email sales@epectec.com.
Stay Connected with Epec Engineered Technologies
Follow us on our social media sites for continuous technical updates and information: