Product FAQs

Power Inverters

What is an inverter?

A device which changes direct current (DC) into alternating current (AC).

What size of inverter should I use?

The size you choose will depend on the watts of the appliance or tool you want to run (find the power consumption by referring to the specification plate on the appliance or tool). We recommend you to buy a larger model than you think you'll need (at least 10% to 20% more than your largest load).

Example: You want to power a computer with 17" monitor and a lamp.

Computer and monitor: 300 Watts
75 Watt lights: 75 Watts
Total Needed: 375 Watts

For this application, you would need a 400 Watt inverter. You should consider a larger unit than your minimum requirements, as there will likely be a time when you wish you would have bought a higher capacity model.

If the wattage of the appliance or tool is not listed explicitly on the specification, you may use the following formula. Multiply: AMPS X 120 (AC voltage) = WATTS.

Example: On the microwave shows 10 AMPS for continuous use.
The Wattage is 10 AMPS x 120 V = 1200 Watt

Why can the 1500 Watt inverter not run my 1200 Watt microwave?

The power commonly advertised for microwave ovens are the cooking power (the power delivered to the food) not the power actually consumed by microwave oven. The microwave ovens might consume 40% to 100% more than its advertised cooking power. The recommended inverter to run 1200 Watt microwave is 2500 Watt or larger.

What is meant by the terms "continuous wattage" and "peak surge wattage" on the inverters?

The "continuous wattage" is the wattage that the inverter can supply 24/7 as long as the DC input power supply is in good condition (usually, the DC power supply is a car battery) The "peak surge wattage" is the maximum wattage that the inverter can supply for very short period of time (a split of a second)

NOTE: Induction motors such as air conditioners, refrigerators, freezers, microwave ovens, and pumps may have a start up surge of 3 to 7 times the continuous rating. Heat generating appliances such as hair dryers and water heaters will have high peak surges as well.

Example:
If the microwave oven has peak surge which is 4 times the continuous wattage, the 1200 Watt continuous microwave ovens will have 4 x 1200 Watts = 4800 Watts peak surge.

The recommended inverter to run 1200 Watt continuous and 4800 Watt peak surge microwave is 2500/5000 Watt inverter or larger.

In general, induction motors require an initial surge of power to start up ("starting load" or "peak load"). Once started, the tool or appliance requires less power to continue to operate ("continuous load")

What is the output wave of the inverter?

Most of the inverters that we carry are "Square Modified Sine Wave."

Note: Wagan Corporation also carries 150 and 300 Watt Pure Sine inverter.

Are there any disadvantages of using "Square Modified Sine Wave" inverter?

"Square Modified Sine Wave" inverters will run most tools and appliances without any problem and are the most common type of inverter on the market.

Below are the advantages of "Pure Sine Wave" (also called True Sine Wave) inverters over modified sine wave inverters:

1. Reduces audible and electrical noise in fans, audio amplifiers, TV and some sensitive audio system.
2. Inductive loads like microwave ovens and motors might run faster, quieter and cooler.
3. The following devices that might not work with modified sine wave inverters:
   - Some battery chargers for cordless tools
   - Some new furnaces and pellet stoves with microprocessor control
   - Sensitive electrical or electronic items such as certain medical equipment

Power Domes

How do you know when it is fully charged?

On the front of the unit there is a “battery status button”. Simply press and hold the button down and the voltage meter on the right side will rise to indicate the charging level. A reading between 13-14V is a fully charged unit.

What does it mean when the inverter is making a high pitch noise?

1. Overload: You may be running more then 400 watts and causing the inverter to shut off.
2. The battery: May not be charged enough to run the inverter. Please hold down the “battery status button” to make sure this is not the issue.
3. In inverter may have an internal defect in which you would need to contact us via email or at 1.800.231.5806

Why is the air compressor not working properly? I can hardly feel the air.

An air compressor is different from an air inflator. An air compressor has high pressure and low flow. This means that when you inflate something with high pressure- like a car tire- it will inflate much quicker then inflating something like an air mattress or a raft.

What is the "safety jumper switch" for?

The safety jumper switch is the "on/off" switch for the jumper cables. After all cables are connected, you can turn on the switch and this will supply the power needed to jump start your vehicle. When you are done with jumpstarting the vehicle, always put the safety switch in the off position.

What is the life span of the Power Dome battery?

The life span of the power dome battery is between 2-3 years.

Is the power dome battery replaceable?

Yes, it is. You may purchase a new replacement battery from www.batteriesplus.com or www.interstatebatteries.com (1-800-CrankIt) or any electronic store location. Here are the specifications to insure that you purchase the correct battery for the Power Dome: Sealed Lead Acid Battery - Rechargeable 12-Volt, 18 Amp Hour.

Please note that Wagan Corp is not affiliated with nor recommends these locations. This is for information purposes only. Transactions with these stores are at customer’s own risk.

Why is my power dome not charging? The red charging light is not lighting up.

If the light does not come on using the AC adapter, please try the included DC adapter. If the light comes on with the DC adapter, then you will know that it is the AC adapter that is defective and not the whole unit. If the DC adapter light is also not turning on, then please contact our customer service department via email or by calling us toll-free at 1.800.231.5806.

Where can I buy a replacement AC charger?

Both the AC and the DC adapters may be purchased directly from our company by calling us toll-free at 1.800.231.5806. However, if we are out of stock or you would like to purchase them elsewhere, then the AC adapter may also be purchased from you local electronic retail store. Here are the specifications that are you will need.

• Class 2 Power Supply
• Input: 120VAC 60HZ 24W
• Output: 12VDC 500mA
• Polarity: Positive Center (Optional)

If the power dome is fully charged out the box, do I still need to charge the unit for the full 34-48 hours?

If the unit arrives fully charged from the store/website you purchased it from, please charge the unit for 24 hours instead of the full 48 hours for the first charge.

How long should I charge my Power Dome?

For the first charge, please charge the unit for the full 48 hours and do not unplug or use the unit until it is fully charged. However, please be sure to not to over charge the unit. For any charge after the initial charge, please charge the unit for 38 hours and be careful not to over charge the unit.

What happens if I exceed 48 hours?

We suggest that you not exceed 48 hours because overcharging the unit will decrease the lifespan of the battery. It is okay to forget once in a while but constantly overcharging the power dome will damage the internal battery.

Can I leave my power dome on the charger all the time?

No, you will be overcharging the unit if you do so. This will decrease the lifespan of the battery and void the limited warranty.

How often should I recharge the power dome if I am not using it?

The Power Dome should be recharged every 2-3 months regardless of use to keep the battery in pristine condition.

I have not used my power dome in 1 year. Now it does not want to hold its charge, what do I do?

With seal lead acid battery, when the battery is completely drained it takes a great deal for it to regain its charge and hold the charge. You may need to leave the power dome on the charger and let it sit for a few days. Sometimes it takes up to 5 days for the power dome to charge and hold its charge.

Where is the power port switch for the DC ports? It is stated in the user's manual but I do not see it on the power dome.

This is an incorrect statement in our manual. There is no DC power port switch because the DC ports are set up to work automatically. Simply plug in your 12V device that is under 400W and your unit will automatically be ready to use.

I accidentally connect the jumper cables to the wrong connections; my entire power dome is not working. What do I do now?

Unfortunately, this would be considered misuse and voids your one year warranty. There is no way to fix this mistake, so please remember to keep your safety jumper switch in the off position until you have the jumper cables connected correctly and ready to use.

If I use my Power Dome to fill up a bike tire, do I need to recharge the unit?

Here is a chart that will give you a good idea as to when you need to charge your unit:

• 15 Volts: Currently charging/right after charging
• 12-14 Volts: Fully Charged
• 12-10.5: Partially charged, May need to be recharged for large jobs (Jump starting or using inverter for a long period of time.
• 10.5 and lower: Power Dome needs to be charged

For further questions, please direct inquiries to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . Thank you!