A power inverter is one of the most useful tools when you’re off the grid whether you’re camping, tailgating or preparing for power outages. It converts 12 volt DC power from your battery into 120 volt AC power, so you can run everyday items like laptops, fans, or even a coffee maker.
But how do you know what size inverter you need? And what kind of battery works best? We’ve broken it down in a simple way, plus we’ve included helpful product links from BatteryMart.com so you can shop smart and get set up with confidence.
Step 1: Know How Much Power You Need
Power inverters are rated in watts and each appliance you plan to use has its own wattage requirement. Here’s a quick look at the average wattages for some common gear:
| Appliance | Watts |
|---|---|
| Cell Phone Charger | 50 |
| Laptop | 25–150 |
| Coffee Maker | 800–1200 |
| Hair Dryer | 900–1600 |
| Microwave Oven | 1500–2000 |
| Flat Screen TV | 65 |
| Gaming Console | 100 |
| Toaster Oven | 1500 |
| Vacuum Cleaner | 1225–1500 |
Quick tip: If an item only lists amps, multiply the amps by 120 to get its wattage.
Step 2: Choose the Right Battery
Not all batteries are created equal when it comes to running a power inverter. You’ll want to avoid regular starting batteries, they’re great for starting engines but aren’t built for a deep, long lasting power draw.
Instead, use a deep cycle battery, which is designed to be discharged and recharged repeatedly without damage. These are rated in Amp Hours (Ah), which tell you how long the battery can supply power over time.
🔋 Check out our reliable deep cycle batteries:
Step 3: Do the Math (It’s Easier Than You Think)
Let’s say you’re powering a laptop (100W), a small fan (75W) and a mini coffee maker (800W). Here’s how to calculate what you’ll need:
- Multiply each item’s wattage by how many hours you plan to use it:
- Laptop: 100W × 3 hrs = 300 watt-hours
- Fan: 75W × 4 hrs = 300 watt-hours
- Coffee Maker: 800W × 0.25 hr = 200 watt-hours
- Total: 300 + 300 + 200 = 800 watt-hours
- Divide by 12V to get amp-hours: 800 ÷ 12 = about 67 Ah
We recommend using a battery (or bank of batteries) with at least twice that capacity, so around 135 Ah. This helps avoid fully draining your batteries and extends their lifespan.
Need a starting point? Try these:
Step 4: Match and Maintain Multiple Batteries
If you’re running multiple batteries make sure they are the same type, brand, capacity, and age. Mixing different batteries can cause imbalance in charging and performance.
Need to expand your battery setup? Shop matching batteries here:
Step 5: Use a Proper Battery Charger
Once your adventure is over (or the power’s back on), you’ll need to fully recharge your battery bank. The best way to do that is with a high-quality automatic battery charger.
Check out these trusted options:
Final Thoughts
A little planning goes a long way. Choosing the right power inverter and battery combo will keep your lights on, coffee hot, and gadgets charged no matter where you go. Whether you’re building a van life setup, prepping for emergencies, or just love your weekend camping trips, Battery Mart has the gear and know-how to keep you powered up.
