Important note: This review is my own honest personal findings after purchasing and using this product. I was not compensated in any manner by any person or entity for this review.We have two ACs on our motor coach; an older 13.5K BTU Dometic Penguin I, and a newer 13.5K BTU Dometic Penguin II. Ours are cooling only, but this product would work equally as well in a heat pump. Please be aware that if your AC or heat pump utilizes any kind of inverter technology, this will NOT be suitable, as the compressor in an inverter drive unit uses a totally different technology, which in fact already operates in a "soft start" manner.We discovered that if we are boondocking when it is extremely hot, and the drive belt in the coach's 7.5KW Kohler diesel generator has some hours on it, and we're running a few other appliances as well as one of the AC units, the AC starting demand of the second unit is enough to cause lots of mayhem with squealing generator belt for several seconds until the AC comes up to speed. Also, it is impossible to run more than one AC on the "just in case" 6.5K surge Harbor Freight quiet inverter gasoline/LP generator we carry in the basement. The last time we boondocked, it was apparent that we desperately needed a good solution to these problems, and I knew that a soft starter was the solution. However, the company who started making these units really have not dropped the price much at all in the past 10+ years or so they've been on the market, so I was not about to spend that kind of money on a box containing less than $100 worth of parts. I was happy to discover several newer companies making these units, and I settled on the SpartanStart based on the few positive reviews I had found, and discounted the couple of negative reviews I saw to obvious operator error. Also, the fact that these are made in Australia is a definite plus. The wife and I are very happy that we ended up with significantly easier to start AC units without the high price tag.With our Dometic AC units, these soft starts were extremely easy to install. Yours should be just as simple. It is a simple matter of identifying the three leads (on our Dometic units, red is start, white is run, blue is common) to determine which of the SpartanStart leads needs to go to which of the AC leads. For our units, that means Spartan red goes to Dometic red, Spartan black goes to Dometic blue, Spartan blue goes to Dometic white - easy as one, two three! Spartan Power has an available chart / installation guide which may or may not be accurate or include your particular unit. I simply used the wiring diagram in the original factory manual for our AC units to decide what needed to connect where. I cut the three Dometic leads in a good dry spot to make the splices, and the conveniently included crimp connectors were used with a ratchet crimper to make the connections. If you don't have a crimper, wire nuts should be acceptable substitutes, as long as they are applied properly. The supply leads which come from the Dometic's power feed connects to the Spartan's clearly identified "SUPPLY" leads, and the Spartan "COMPRESSOR" leads connect to the Dometic's compressor - yet another "no brainer". Please note that any original starting components MUST be disabled or removed from the system for this to work, as the SpartanStart has built-in circuitry which replaces the original starting circuit. In this case, I simply disconnected the lead going to the PTC thermistor and secured it in the junction box, but left the PTC, start capacitor, and all the original leads there. This way, if this SpartanStart ever goes North, I can easily bypass the unit and return the AC to working condition in just a few minutes.As far as effectiveness, I could not be happier! Using a Fluke i1010 clamp-on current clamp and a Fluke 187 multimeter set to MIN/MAX, I monitored total inrush current on the supply line. Here is the measured starting currents on the AC units.Penguin I:Before SpartanStart: 52.7AAfter SpartanStart: 27.1APenguin II:Before SpartanStart: 49.5AAfter SpartanStart: 21.3AAs noted, this is total current, which will include the running current of the blower fan which starts and comes up to running speed several seconds before the compressor. This is due to the compressor start delay provided by the Dometic thermostat, and also any start delay from the SpartanStart. The Dometic blower has three speeds, and these tests were conducted with the blower on High. Further, albeit minor start current demand reduction could be seen by manually setting the AC unit's blower to low. As expected, no run current reduction was seen, verifying the SpartanStart does indeed have a hard relay bypass after it starts the compressor. The run amps on both units remained around 11.3A on the Penguin I and 12.5A on the Penguin II (verifying also that R12 is a more efficient refrigerant). Finally, not to be understated, the rooftop units are now considerably quieter when they start, No longer does it sound like an opossum dropped on the roof when the compressor is engaged! I am certainly looking forward to a more peaceful sleep while running the AC, and this is hands-down the #1 reason to install the SoftStart even if you have ample generator supply or always plug in at the park.The inrush current was measured during several restarts after installation on both units, and it appears certain there is no "learning" period for this unit, as compared to the other models on the market. It simply works right out of the box, and no sizable decrease in starting current is realized after several restarts that can't be attributed to the compressor warming up. It is debatable whether this is good or bad - but the evidence shows that we can now successfully start BOTH/EITHER unit(s) while running on either the coach generator or the quiet inverter generator without issue. With the inverter generator we just have to make sure to not allow both AC units start at the exact same time; as long as one unit has already started, the other unit can be turned on within a few seconds and the generator successfully starts the second unit. From what it seems, if you happen to have at least a 3000W pure sinewave DC inverter, this would allow a similarly-sized AC to run.It should be noted that the difference in starting currents seen between our two units are likely due to age, with the Penguin I being around 12 years older with likely many more hours on it than the Penguin II.After testing, all that was left to do was to permanently mount the units, and the pictures show where these were placed. The unit specifically states to mount them out of the way of any heat sources, so I found a place which was not in the direct path of the hot condenser air discharge. The only "knock" I have against the SpartanStart is that I'm much of a fan of using the double sided super tape they include as a mounting solution, so I made sure to mount them in a spot where if they do come loose, they won't damage anything or be damaged. That being written, so far they are holding up to the vibration, heat, and use. Due to the way the AC is constructed, the SpartanStart needed to be mounted upside down on the Penguin I to allow the status lights to be seen. The AC covers fit back on just fine with plenty of clearance.This review will certainly be updated if we run into any unusual longevity issues. I expect these units to last for years, if not the life of the coach, since we only use the motorhome a handful of times a year during the cooling season - far less than one would experience at home.I believe a Spartan SoftStart would be a wise investment for your RV if you ever experience issues with your AC / heat pump starting, especially considering how much less expensive it is as compared to its competition.

Installed in about 10 minutes, works perfectly. Our Champion 2500 watt inverter generator can now start and run our single 13,500BTU AC on our trailer - even on propane (propane has less energy than gas, so the generator only puts out about 22-2300watts on propane). I do have to put the generator off of ECO mode, or it will sometimes trip. But if I leave ECO off, it has no issues running the AC for hours. In fact, if its not TOO hot out, it will even run it with ECO on - you just run the risk of it tripping after a few AC cycles.Much cheaper than competing brands, and came with everything needed to do the install.

Delightfully Surprised. Install was very easy. I'm good with wire strippers, crimper, and a heat gun. I did shorten the generously long leads to fit my situation (I'm a voltage drop snob), and I used my own heat-shrink butt connectors for a watertight and strain-resistant connection. Trimming the leads isn't really necessary since they're at least one AWG heavier than the compressor's wiring. Spartan thought of everything.My first test was on a 3kW inverter/3.5kWh LiFePO4 12v battery. I left the fridge and the computer on since this device should be able to soft start my 13.5kbtu Dometic rooftop AC on the remaining power available. And holy cow does it work! No more loud thump when the compressor kicks on and off. I let it run several cycles and the power didn't even hiccup. No more momentary 300A current spike from the battery. Before the Spartan, it was hit-and-miss at startup. About 50% of the time the inverter would halt by overcurrent even with the fridge on LP, and the compressor would buzz and protest while the inverter did eventually kick it on. The Spartan is installed in series with the Dometic Hard Start kit with zero issues.With my little 2000W Harbor Freight Honda clone, the AC started with ease. The generator rev'd up smoothly and didn't need to go wide-open to handle the inrush. Nice!On shore power plugged into the 30A receptacle in the workshop, startup is much less of an event. The lights used to brown out/flicker when the AC started. With the Spartan I couldn't even be sure the AC came on until I went outside. It's so much quieter at startup. The most noticeable startup noise is the blower/condenser fan.I had originally planned on buying the other name brand SSRV device recommended by every Internet RV professional in the universe, but I didn't need anything to regulate the blower/fan motor...I wanted to keep my variable fan speeds. So I kept an eye out for a soft start kit that focused on the compressor only. It was between the Spartan and the various clone models from the Far East for fifty bucks cheaper. The reviews and marketing sold me on this model, especially since it's recommended by (and perhaps built for) outback overlanders. This unit fits my needs perfectly. No more, no less.I'll test with my little 2500W Harbor Freight Honda clone generator this week, but I'm already 100% confident it'll handle the AC way easier now.This little box is a game changer, and it's going to pay for itself by prolonging the life of my compressor motor windings, inverter, batteries, and the "little generator that could".Great Job, Spartan!Cons: The case is well built but is just a bit bulky. That's all I can think of on the negative, and it's not that big of a deal. It's probably smaller than the competition either way.

Installed three of these soft starts on some old Dometic heat pumps in my Class A motorhome. Instructions were clear, wires are nice 10-gauge tin plated and plastic case robust. It comes with 3M VHB tape on back to mount but I felt better adding some adhesive and mounting flat down. I have a large lithium battery bank and two Victron MultiPlus Inverters in parallel. Without these soft starts, I couldn't start even one AC without the sensitive TV going out and struggled to even get two running at a time. Now I can easily run all three heat-pumps if needed without the power system bogging down and kicking out.

This soft start for out air conditioner works great. It was easy to install and the tapes stick very well. It allows us to use the AC on 30 amps instead of the 50 amp normally needed. Saves us on having to run the generator.