Frequently Asked Questions
Will this run my refrigerator?
A household fridge runs on 100–800W but spikes at startup. A 2000W pure sine wave inverter covers a standard fridge comfortably. Check the label on your unit and compare it to the continuous rating on the product page.
Will it run my air conditioner?
A rooftop RV air conditioner needs a large startup surge. Read the surge rating, not the continuous rating, and check your AC's locked rotor amps. If you are unsure, email us the model number.
Will it run a CPAP?
Yes, and this is exactly why you want pure sine wave. Modified sine wave inverters cause problems with CPAP machines and other sensitive electronics. Everything we sell is pure sine wave.
Will it run my microwave?
A 1,000W microwave draws about 1,500W running and can ask for 2,400W to start. Plan on an inverter rated roughly twice the microwave's cooking wattage.
What is the difference between continuous and surge power?
Continuous is what the inverter delivers indefinitely. Surge is a short overload it tolerates for a second or two while a motor spins up. Size your system on continuous.
Will a 24V inverter work on my 12V batteries?
No. There is no adapter for this. Match the inverter's input voltage to your battery bank. Every product page states it.
Is this a real MPPT controller or a PWM in disguise?
A genuine MPPT controller has a wide PV input window well above battery voltage, and it has real weight because it contains an inductor and a heatsink. We publish both the PV voltage range and the shipping weight on every controller page so you can check before you buy.
How big an array can my charge controller handle?
Multiply the controller's amps by your battery bank voltage. 60A on a 12V bank is roughly 720W of panels; on a 24V bank, roughly 1,440W.
Does the fan run all the time?
It depends on the model, and we state the fan behaviour on each product page. It is one of the most common complaints in this category, so we would rather you know before you order than discover it in your van at night.
What comes in the box?
Every product page lists exactly what ships, including cables and fuses when they are included. If a cable is not included, we say so.
What size battery cable do I need?
It depends on your inverter's wattage, your system voltage and the length of your run. Use the gauge specified in the manual. Undersized cable is the most common cause of overheating in this category — email us your run length if you want it checked.
Where does my order ship from?
From a warehouse inside the United States. Orders are dispatched in 1–2 business days and typically arrive in 3–7 business days.
Do you ship outside the US?
Not at this time. We ship to all 50 states, DC, and APO/FPO addresses.
What if it arrives damaged or dead?
Email support@prestonsupply.com within 7 days of delivery with a photo. We send a replacement or refund you in full, return shipping included. See our refund policy.
Can I return it if I ordered the wrong size?
Yes, 30 days from delivery, unused and in original packaging, return shipping paid by you. Or email us before you order and we will help you get it right the first time.
How do I reach a human?
support@prestonsupply.com, Monday to Friday, 9am–6pm ET. We answer within one business day.