The use of sight glass for charging is common in refrigeration. It is better to charge a system first by measuring the operating condition (discharge and suction pressures, suction line temperature, compressor amps, super heat, sub-cooling and coils temperature differential) before using the liquid line sight glass. If the sight glass is close to the exit of the condenser or if there is very little sub-cooling at the sight glass, bubbles may be present even when the system is properly charged. If a system is charged to full sight glass, overcharging may be the result, decreasing efficiency.
Since one of the reasons you invested in an EV or PEV was to give fossil fuels the boot, the last thing you’ll want is to continue powering it with dirty fossil fuel and nuclear-made electricity—common grid sources in nearly all parts of the United States. How about a PV system to charge your EV or PEV?
Vehicle manufacturers establish A/C system charges in an environmental test facility by running a charge determination test procedure at high ambient load conditions.