TymateRV Tire Pressure Monitoring System - M7-3 TPMS Tire Pressure Monitor System(0-87 PSI) with Solar Charger, RV TPMS with 4 sensors & 5 Alarm Modes, LCD Display, Auto Sleep Mode, Easy to Install

The unit is really easy to setup and use.I fully charged the Head unit which didn't take all that log, using the provided USB "C" Cable and should stay charged from here on using the built in solar cell on the unit.The unit was already "Paired" to the already configured sensors.LF, LR, RF, RRThe only reason my rating isn't higher is for the following.1. The sensor for the RR would display any info. Turned out that the battery on the sensor was dead, I checked it with a battery tester.2. The enclosed manual says that the sensor battery is a CR2032 which it is not. it is a CR1632 which is a slightly odd unit to get at your local store.3. All the sensors were active and powered on, using / draining the batteries while sitting new in the box.4. The unit does not turn itself on or off. If you don't turn it on, you have no monitoring or alarms. If you leave it on for long periods of time, it may be dead if the sun isn't strong enough or you have parked in the shade etc, once again leaving you without monitoring or alarms.One thing I'm interested to see is how long the Lipo battery holds up. Usually in low cost items like this the LIPO battery is on of those inexpensive bag types that doesn't take heat or especially freezing temperatures without being killed.UPDATEI have left the unit turned on for several days in a row. Even in low lighting, like overcast days, its still enough to keep the units battery charged. so that is one concern that is resolved,

This has saved us twice when on a road trip with our 37 ft RV. Both times, our tires were losing air rapidly, and it alerted us so we were able to pull over safely. If we had not had this system, we would have never known and caused major damage or been stranded, blocking traffic. Definitely worth the peace of mind.

I bought this to use on my single axle small trailer. Reading about trailer tires, I have learned that proper pressure is even more critical than with car tires. They are also more prone to rapid pressure loss / blowouts. A TPMS can at least provide some margin of safety against those problems. Internal systems are expensive to buy and then must be mounted inside the tires, another expense. The external system addresses both issues. Within the constraints of an external system, this product works well. I give it 4 stars, knocking one star off for being a little inaccurate and some other quirks. Overall, it's a good system and at this price, I will keep it.ProsVery easy to install and use. You take off the dust cap and mount a sensor in its place with a dust cover and locking nut behind it.The monitor is a nice size, large enough to read but small enough to just sit on the side of my dashboard.It is solar powered so no batteries and no necessity to hook up to a power though a cord and plug are provided if you choose to do so.ConsNot perfect accuracy but to be fair, probably within the specs provided. I checked each tire with a known gauge. Two sensors are about 2 pounds low while a third was pretty much spot on. I used the third one on the spare tire and am not using the fourth.To preserve battery life in each sensor, they are motion activated and then only transmit if there is a change in pressure (and I think temperature). That makes sense. However, that also means that you cannot check the cold tire pressure before heading out. I'm told with trailer tires this is important to do. The only way to check the pressure is to unscrew and remove the sensor, check the pressure, and then remount the sensor. You lose a little air as you take it off and then again when you remount it. The instructions say you really should check with soapy water when you install a sensor to make sure you don't have a leak. You are also supposed to loosen and then re-tighten the locking nut behind the sensor. Note this is not a fault of this system as I assume this is the case with all of these externally mounted monitoring systems. I wish there was an override button on the sensor to manually get it to send a reading. That would make it easy to check pressure while still retaining the protocols to enhance sensor battery life.The motion activation and only sending a signal for significant changes also seems to lead to unpredictable first reads. On my initial trip that was on a smooth interstate, I got the first tire reading after about 10 minutes but the second tire reading didn't show up for nearly an hour. The reading for the spare was closer to 90 minutes after I left. If I knew the pressure was correct when I left, i suppose that would be ok, but as noted above, you don't know that unless you take off the monitors and check with a gauge. In my view, the system should be set up to send an initial reading at motion activation. That would also let you know that system was in fact working. This system does not do that.I camped in Colorado at a high altitude (8,600') with cold nights. When I left in the morning after a few days, I assumed the pressure was lower. I didn't bother to check since I had no way to add air anyway. In this case, all three tires reported right away as I drove out the dirt road within the campground.I've read that there may be external sensors with pass through channel that allow pressure checking and adding air. That might be an option to consider.Conclusion is that while not perfect, this system does give me some peace of mind that i will notice if a tire is rapidly losing air. For $60, that's well worth it. I'll continue to look at other systems for future consideration.

Super easy set-up, easy to read display, and well-built reliable tire sensors. Towing a single axle camper trailer, this tire pressure monitor brings great peace of mind when it comes to tire air pressure and temperature. No sign of air leakage so far, but we normally expect to check tires and add air at the beginning of every trip.