Electronica: Eval kit estimates remaining charge in novel Li-ion cells

Author: EIS Release Date: Nov 21, 2022

NGK Insulators has revealed a fuel-gauging evaluation kit for its novel Enercera lithium ion cells, some of which are amongst the few Li-ion cells to be chargeable below 0°C, and some of which can be float-charged.

 

NGK Onsemi remaining enercera capacity eval board

“As part of development support,” said the company, “NGK will provide all customers that use EnerCera with reference designs and evaluation boards free-of-charge starting from November 2022.”

 

The kit, LC709204FXE-N01-GEVB, uses an LC709204F battery sensing IC (see below) from Onsemi – a company which was involved in the kit’s development – and a microcontroller driving a PC-based graphical interface.

 

NGK Onsemi remaining enercera capacity eval system“In addition to remaining battery capacity, it enables the visualisation of conditions such as voltage and temperature,” according to NGK. “The evaluation system also eliminates the need for verification of individual data of battery, which had previously been required to measure remaining battery capacity, and can verify items such as the load and stability of EnerCera while the device is operating.”

 

Electronics Weekly covered EnerCera technology in detail here. There are semi-solid pouch and coin types, with unusual characteristics due to material choice – particularly NGK’s ‘crystal oriented ceramic plate’ electrodes.

 

“NGK realises characteristics sought in power sources for IoT devices such as high capacity, high output, heat resistance and a long lifespan, which were difficult to combine in conventional Li-ion rechargeable batteries,” it claimed.

 

Onsemi LC709204F Liion fuel gauge appGeneric LC709204F application circuit

 

LC709204F is a fuel gauge IC for one-cell Li-ion or Li-polymer batteries and uses a configurable Onsemi algorithm dubbed ‘HG-CVR2’ to estimate a battery’s relative state of charge ” even under unstable conditions such as changes in battery temperature, loading, ageing and self-discharge”, claims Onsemi.

 

The IC can also report state-of-health and has multiple integrated alarm functions for battery safety.