Portable air compressor advice is needed
I'd like to purchase a dc powered portable air compressor for my travel trailer, just in case I need to top off the tires while on the road. I already own two other compressors that I prefer to leave...
Forum Discussion
I bought a MV-50 in 2007 for 60ish$$ IIRC.
I disliked the screw on shrader valve connection. Had to sit there and hold it if there was any stress on the valve stem by the coiled hose, for the whole filling, to prevent it from leaking.
I wound up modifying the hose and schrader valve connector and added a 80mm fan blowing over the head.
The QC on mine was quite poor, the splices and crimps in the tailcap was very poor, no strain relief on the wire exit. The headbolts loose, the finned heatsink head only touches the cylinder walls in 3 places meaning poor heat transfer. The simple reed valves inside hardly seal perfectly.The hose and head employs some metric quick connect fitting not standard 1/4 NPT air fittings widely used in North america, but retaps easily enough for 1/4 npt. The airfilter intake holes were mostly filled with the flashing from the mold, significantly choking off the airflow.
I use mine to pump up my firestonre ride rite airbags to 100PSI. 90 to 100PSI takes as long as 0 to 90 does. My 30 amp fuse has never blown, is still original, but I never hook mine to a 45+PSI tire/airbag, then turn it on, I turn it on first.
Mine draws 16 to 19.5 amps ( depends on voltage and air pressure) and I still have the original ~6 feet of 14AWG to the internal relay, despite wanting eventually to feed with 10awg. When I hook it direct to my 40 amp DC power supply at 14.7v over 45 amp anderson powerpoles, the motor spins so much faster, compared on a 12.8v battery so 10AWG feeding it would likely reduce fill times significantly.
The MV-50 and its clones can be spit and polished into a capable reliable machines, but there could be something newer, and similar price range, which could be even better, with adequate amounts of spit and polish or more money spent on a Viair that likely does not require it.
Avoid any 12v unit with a ciggy plug. Those are for low PSI passenger car tires and owners not capable of determining where red and black clamps go.
The run times/duty cycle before overheating is certainly a factor. My improvements regarding heat transfer from cylinder and the relatively weak 80mm computer fan certainly help, but I'd question if it could fully fill a huge high PSI rv tire to 100+ PSI without getting ridiculously hot. I went through a dozen 12v air compressors before teh MV-50, but they were all ciggy plug low priced jobs, which all overheated and became noisy deflaters once they did overheat and burnt out the cylinder cup.
I disliked the screw on shrader valve connection. Had to sit there and hold it if there was any stress on the valve stem by the coiled hose, for the whole filling, to prevent it from leaking.
I wound up modifying the hose and schrader valve connector and added a 80mm fan blowing over the head.
The QC on mine was quite poor, the splices and crimps in the tailcap was very poor, no strain relief on the wire exit. The headbolts loose, the finned heatsink head only touches the cylinder walls in 3 places meaning poor heat transfer. The simple reed valves inside hardly seal perfectly.The hose and head employs some metric quick connect fitting not standard 1/4 NPT air fittings widely used in North america, but retaps easily enough for 1/4 npt. The airfilter intake holes were mostly filled with the flashing from the mold, significantly choking off the airflow.
I use mine to pump up my firestonre ride rite airbags to 100PSI. 90 to 100PSI takes as long as 0 to 90 does. My 30 amp fuse has never blown, is still original, but I never hook mine to a 45+PSI tire/airbag, then turn it on, I turn it on first.
Mine draws 16 to 19.5 amps ( depends on voltage and air pressure) and I still have the original ~6 feet of 14AWG to the internal relay, despite wanting eventually to feed with 10awg. When I hook it direct to my 40 amp DC power supply at 14.7v over 45 amp anderson powerpoles, the motor spins so much faster, compared on a 12.8v battery so 10AWG feeding it would likely reduce fill times significantly.
The MV-50 and its clones can be spit and polished into a capable reliable machines, but there could be something newer, and similar price range, which could be even better, with adequate amounts of spit and polish or more money spent on a Viair that likely does not require it.
Avoid any 12v unit with a ciggy plug. Those are for low PSI passenger car tires and owners not capable of determining where red and black clamps go.
The run times/duty cycle before overheating is certainly a factor. My improvements regarding heat transfer from cylinder and the relatively weak 80mm computer fan certainly help, but I'd question if it could fully fill a huge high PSI rv tire to 100+ PSI without getting ridiculously hot. I went through a dozen 12v air compressors before teh MV-50, but they were all ciggy plug low priced jobs, which all overheated and became noisy deflaters once they did overheat and burnt out the cylinder cup.
