Insulation resistance requirements for energy storage battery packs

What is a good isolation resistance for a battery pack?

The isolation resistance of 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. The NHTSA list values for a Tesla in their Tech Note :

How to test battery cell insulation resistance?

Battery cell insulation resistance testing is generally carried out as follows (*1): DC voltage is applied between each cell’s anode and cathode, and the insulation resistance is measured. DC voltage is applied between each cell’s electrodes and enclosure, and the insulation resistance is measured.

What type of insulation does a battery need?

The insulation has layers including nonwoven oxidized polyacrylonitrile fibers with high temperature resistance, wool paper/blankets, and metallic foil facing layers. This multi-layered insulation provides insulation, fire containment, and thermal runaway protection for batteries without active cooling systems.

Does material insulation affect thermal spread inhibition performance of lithium-ion battery module?

The thermal spread suppression experiment was carried out by using the control variable method, and the influence of different material insulation layers on the thermal spread inhibition performance of lithium-ion battery module was studied.

What is an insulating piece in a battery pack?

An insulating piece is placed between the cell wall and converging component to isolate and insulate the wall from the converging part. This prevents short circuits between the bus bar and case. Anti-heat insulation battery pack for electric vehicles with improved thermal protection and mechanical strength.

What voltage is used in battery insulation resistance testing?

The test voltage is the voltage that the insulation tester applies to the cell under test. The appropriate test voltage varies from battery to battery. DC voltage of 100 V to 200 V is generally applied in battery cell insulation resistance testing. Recently, it has become more common to use a low voltage such as 5 V or 50 V.