#1 Best Overall – SoftStartRV
- 40% smaller than Micro-Air
- Run 2 A/Cs on 30-amp
- Works with small generators
- Free install kit + 3-yr warranty
Soft Start RV | Easy Start
No 30 or 50 amp plug available? Here’s how to run your RV air conditioner from Lithium System, any standard plug or small generator.
Why a Soft Start is an Absolute Must-Have
Living in Texas, one of our most important priorities of RV life is the ability to run the air conditioner no matter where we are or what power source we have available.
Soft Starts are a must, in my opinion. By reducing the massive power surge that occurs on startup, I’m able to run the rooftop A/C from nearly any source — including a household 15/20-amp plug, my Lithionics lithium battery system, or even both A/Cs at once on 30-amp service in the Airstream.
This gives us the freedom to keep the RV cool for us and our pups — no matter where we boondock.
Your factory RV air conditioner draws a huge inrush current (often 70–100+ amps!) because the compressor is designed to pull whatever power it needs to spin up instantly. That surge trips breakers and kills most inverters.
A Soft Start solves this completely by limiting startup current by 60–75%, eliminating voltage drops, protecting electronics, and dramatically extending compressor life.
Hard-wired versions are “install once and forget” — required if you want to run A/C off lithium batteries. The only downside: roof install and possible (but rare) warranty concerns.
External versions are plug-and-play — perfect if you never plan to run off batteries and don’t mind plugging it in each time.
I personally only use and recommend hard-wired units.
My Top Soft Start Recommendations
External Plug & Play – SoftStartUp
- No install required
- No roof work or wiring
- No warranty concerns
- Perfect for occasional use
Runner-Up – Micro-Air Easy Breeze
- Same performance as #1
- Bluetooth app
- Needs 5 learning cycles
- Slightly less expensive
Not sure which one is right for your rig?
Email me → Let's chat
Frequently Asked Questions About RV Soft Starts
Do I really need a soft start to run RV A/C off lithium batteries?
Yes — 100% required.
Without a hard-wired soft start, your rooftop A/C compressor draws 70–100+ amps on startup. No inverter (even 3000W+) can handle that surge without shutting down or tripping.
A SoftStartRV or Micro-Air reduces startup current to ~25–30 amps, letting you run 13.5k–15k BTU units for hours off lithium batteries.
Can I run my RV air conditioner on a household 15 or 20 amp outlet?
Yes — but only with a hard-wired soft start.
Factory RV A/Cs pull 60–90+ amps on startup and instantly trip standard household breakers. A SoftStartRV or Micro-Air cuts that surge by 70%+, allowing full operation on a normal 15 or 20 amp plug.
Will installing a soft start void my RV air conditioner warranty?
Technically possible, but extremely rare in practice.
Dometic, Coleman-Mach, and Furrion state that aftermarket modifications “may” void warranty at their discretion. In over 5 years and thousands of installs, I’ve never seen a warranty claim denied because of a soft start.
What’s the difference between hard-wired and external soft starts?
Hard-wired (SoftStartRV, Micro-Air Easy Breeze):
• Permanent roof install
• Required to run A/C off inverter/batteries
• True “install once and forget”
External (SoftStartUp):
• Plugs inline with your shore power cord
• No install, no roof work
• Cannot run A/C off batteries
Which soft start is actually the best in 2025?
After testing every brand in 100°+ Texas heat:
#1: SoftStartRV → Smallest, quietest, fits Truma A/Cs, 3-year warranty
Runner-up: Micro-Air Easy Breeze → Great Bluetooth app, slightly cheaper
Best external: SoftStartUp → Plug-and-play convenience
I personally install SoftStartRV on every customer rig.
Can I run two RV air conditioners on 30-amp service?
Yes — only if both units have hard-wired soft starts.
Without them, the second A/C trips the 30A breaker on startup. With SoftStartRV or Micro-Air installed on both, two 15k BTU units run perfectly on a single 30-amp connection (confirmed on Airstreams, Grand Designs, and Olivers).