Andy Tirado from AVI discusses crucial HVAC maintenance for battery electric and hybrid electric vehicles. The primary difference in these systems is the high-voltage compressor and its specific oil requirements. PAG oil is incompatible; instead, use POE or NG100, which are less conductive and offer more insulation. This is vital because as bearings wear, metal particles circulate. In a high-voltage system, these conductive particles can abrade windings, leading to shorts or insulation breakdown. Additionally, the HVAC system in these vehicles is integral to battery thermal management; a malfunctioning AC can cause battery overheating.