Air conditioner soft starter
Spartan Power SpartanStart Soft Start Kit Specs and Sizing
Researched from published standards and manufacturer specifications. Updated .
Quick answer
This is a specification sheet rather than a review. Every figure below comes from the manufacturer listing, and we do not test products in person. What this page adds is context: what these numbers mean for an RV system, and what else you need to buy alongside it.
Best for: A standard rooftop unit up to 20,000 BTU.
Spartan Power SpartanStart Soft Start Kit specifications
| Specification | Value |
|---|---|
| Max Btu | 20000 |
| Voltage | 120 |
Published standard Source: Manufacturer listing. Specifications and pricing change without notice. Confirm on the listing before buying.
What does this component need alongside it?
Check the cable size, the fuse rating and the compatibility with your battery chemistry before installing this component.
How does it compare with other air conditioner soft starter options?
| Component | Price | Notable spec |
|---|---|---|
| Spartan Power SpartanStart Soft Start Kit | $189.00 | maxBtu: 20000 |
| SoftStartRV Soft Start Kit | $295.00 | application: Rooftop RV air conditioner |
| SoftStartUp Plug and Play RV A/C Soft Start | $595.00 | application: Rooftop RV air conditioner |
Published standard Source: Manufacturer listings.
SoftStartRV Soft Start Kit
$295.00A soft starter cuts the compressor inrush, which is what lets a rooftop air conditioner start on a smaller generator or on an inverter.
Best for: Running air conditioning on a 2000W class generator.
Check price on Amazon
SoftStartUp Plug and Play RV A/C Soft Start
$595.00Plugs in rather than being wired into the air conditioner, which keeps the job out of the rooftop unit entirely.
Best for: Anyone unwilling to open a rooftop air conditioner.
Check price on AmazonAir conditioner soft starter options
Spartan Power SpartanStart Soft Start Kit
$189.00Rated to 20,000 BTU, which covers the common 13,500 and 15,000 BTU rooftop units.
Best for: A standard rooftop unit up to 20,000 BTU.
Check price on Amazon SoftStartRV Soft Start Kit
$295.00A soft starter cuts the compressor inrush, which is what lets a rooftop air conditioner start on a smaller generator or on an inverter.
Best for: Running air conditioning on a 2000W class generator.
Check price on Amazon SoftStartUp Plug and Play RV A/C Soft Start
$595.00Plugs in rather than being wired into the air conditioner, which keeps the job out of the rooftop unit entirely.
Best for: Anyone unwilling to open a rooftop air conditioner.
Check price on AmazonFrequently asked questions
- What is the Spartan Power SpartanStart Soft Start Kit best for?
- A standard rooftop unit up to 20,000 BTU. Rated to 20,000 BTU, which covers the common 13,500 and 15,000 BTU rooftop units. Confirm the current specification on the listing before buying, because manufacturers revise these products without changing the model name.
- Is the Spartan Power SpartanStart Soft Start Kit suitable for a lithium system?
- Check the charge profile before pairing it with lithium. The requirement is a genuine LiFePO4 profile with the correct absorption voltage, not a lead-acid profile with a lithium label. Where a component only charges at lead-acid voltages, a lithium pack will sit permanently short of full.
- What size cable and fuse does it need?
- That depends on the current it carries and the length of the run, not on the component itself. Work out the current from its rating, then size the conductor for both ampacity and voltage drop with the wire gauge calculator, and fuse it at 125 percent of the continuous load rounded up to the next standard rating.
Wiring safety. Never exceed a conductor's rated ampacity, and always fuse a circuit at or below what the wire can carry, because the fuse protects the wire rather than the appliance. Fuse every positive conductor as close to the battery as practical. Use proper crimped lugs and heat shrink rather than twisted joints, support cable so it cannot chafe through on a frame edge, and keep the battery compartment ventilated. Permanent AC wiring is work for a qualified RV technician or a licensed electrician.