12v inflation devices blow lots of fuses and have very short lifespans. Compressors make hot air, hot hoses, hot nozzles, hot meters. Hence the higher pressure displayed. NEVER run them for more than 1 tire until they have completely cooled to room temperature.
Use CO2 cartridges. Trust me. Way better. Way faster. Dry air instead of wet.
Use CO2 cartridges. Trust me. Way better. Way faster. Dry air instead of wet.