HV Definitions and Glossary

The HV Definitions & Glossary is an A to Z extension to our website that just gives you an alternative way of finding information.


Busbars are the main electrical connections between cells, modules and connect all of the HV system to the outlet connector. Normally made from copper or aluminium.

Clearance – the line-of-sight distance between two conductors through the air.

Charge Voltage – voltage that the battery is charged to when charged to full capacity.

Contactor – a switch that can be operated by the control system. They are essentially a relay.

Creepage – the distance between two conductors on the surfaces of the parts or along the surface of the insulating material.

Current Sensor – can include resistive or magnetic elements based on their structure. We use these elements for sensing the current to be measured.

Cut-off Voltage – the minimum allowable cell voltage defines this lower voltage limit.

Fuse – device that protects electrical circuits against undesired high currents. We can use passive fuses and pyro fuses in battery design.

HV – abbreviation of High Voltage and in automotive world this means above 60V DC.

HVIL – Hazardous Voltage Interlock Loop.

Isolation Resistance of a Pack – for the complete HV system to ground with the contactors closed should be >500Ω/V and hence for a battery pack its resistance target must be specified by the HV System designer, typically >1,500kΩ.

LV – abbreviation of Low Voltage and in automotive world this means below 60V DC.

Nominal Voltage – reference voltage of the battery at 50% state of charge and at the defined discharge rate.

Pre-Charge Resistor – when the battery pack contactors are closed onto a motor and inverter there will be an inrush of current into the inverter capacitor. This very high current is at a minimum likely to age the contactors, it could permanently damage the contactors.

Pyro Fuse – a fuse that can be blown by a signal.