What is the Difference Between Batteries and Generators?

There are many types of power generating systems. This article will clarify the differences between batteries and generators according to your needs and living accommodation.

Battery Generators (known as Portable Power Stations and Solar Generators) store energy generated from solar panels or the grid to power your home appliances and equipment. Conventional and Inverter Generators provide the same power as batteries except that the energy is generated from their internal fuel engines.

What are battery generators and generator batteries?

Battery Generators are known as Portable Power Stations and Solar Generators. A battery generator is not a generator; it stores energy generated from solar panels obtained from the grid or wind turbines.

Battery Generators are power banks on steroids that provide USB outlets, standard 110-volt household outlets, 12-volt car socket outlets, and 12-volt DC ports. They can be charged through your home 110-volt regular outlets but, more importantly, can also charge from solar when the power goes out.

The largest breed of battery generators is whole-house backup systems such as Tesla’s Powerwall. Whole-house backup systems are a permanent installation that requires enough space for a large battery bank and a large roof surface area to install solar panels.

Energy generated from the solar panels can be either sold back to the grid or stored in the battery bank for later use in the event of a power outage or during the day when electricity prices are at their highest (also known as energy arbitrage). In some models, battery generators can remain on standby and kick in by themselves when a power outage occurs.

On the other hand,

Generator Batteries are the small batteries found in Conventional and Inverter Generators which use gasoline and propane to run their engines. These batteries do not provide you with power but rather power the ignition start of the generator (much like your car) instead of using a starter rope.

Conventional and Inverter Generators use 12-volt batteries. Generator batteries are pretty small and will usually be about the size of a brick that you can hold in your hand (the size of a motorcycle battery). Keep in mind these small batteries come in different sizes depending on your generator’s type and brand. Standby generators use the biggest size, which is a standard car battery.

Here is a simple battery maintenance tip that will allow you to always start your generator with an easy push of a button and keep your battery in optimal health:

Connect your generator’s battery to a trickle charger for 24 hours every 3 months to make sure it is always ready to start your generator, especially if you are putting it away in storage.


As the battery gets old, you might need to trickle charge it more often (once a month) due to its decreased ability to hold a charge for a long time.

Usually, generators charge their battery while in operation (some don’t though!), so it is always best to trickle-charge your batteries to extend their useful lifetime. A generator that doesn’t run long enough or is put away for too long will have a depleted and possibly damaged battery due to a low charge.

Batteries should always be stored fully charged and replenished every 3 months to maintain optimal performance.

Since I am using a citation from Generac, I would also like to remind you that they confirmed the following:

Some Generac models charge their battery while the generator is running, and others don’t so make sure to check your owner’s manual.

Battery generators (Portable Power Stations and Solar Generators)

Battery-powered generators have been around for a while but have recently gained the public’s attention as the technology improved. Battery-powered generators are known as Solar Generators, Portable Power Stations, Home Battery Systems, and many other names, but those are the most common ones.

As we are gradually becoming more reliant on backup power, I expect the prices for all types of battery generators to start dropping over the coming years.

A battery-powered generator is an integrated system with a few components. First, the batteries are charged either from solar panels (through a charge controller device) or straight from the grid. Then an inverter is connected to the battery’s output to produce 110-volts through regular household outlets and many other outlets such as USB.

Below are all the sources that can charge your Portable Power Station:

  • The Main Grid
  • Solar Panels
  • Wind Turbines
  • Conventional and Inverter Generators
  • Other DC power sources such as 12v car outlets  

Remember that the size of a battery system is directly correlated with the amount of power it can provide. Portable Power Stations are best for short weekend trips or apartments (as they are not allowed to run conventional or inverter generators). A Powerwall, on the other hand, will run your entire house in case of a power outage.

10 Pros for Battery-Powered Generators known as Portable Power Stations

1. Battery-powered generators are good to go if you live in an apartment. Traditional gasoline and propane generators emit carbon monoxide and are therefore not allowed in any closed areas.

2. You can charge any device on the go without worrying about gasoline or propane. You can always have your little portable power station to cover your basic needs over a weekend without needing to recharge.

3. They produce clean power with a very low THD and is therefore safe for all sensitive electronics.

4. You and your neighbors will be happy as they produce no noise (it has no mechanical moving parts inside).

5. You can top off your battery from many sources:

  1. Portable solar panels
  2. Any standard 110v wall outlet,
  3. Conventional and Inverter generators,
  4. A charged portable power station,
  5. Wind turbines,
  6. A 12v car outlet,
  7. Cherry on top some models can be charged for free at many Electric Vehicle Charging Stations around the country. 

6. They require zero maintenance.

7. They are safe to operate unattended and around children as they don’t emit carbon monoxide.

8. They can be as small or as big as you want them. Starting with cell phone power banks all the way to fullfledged home backup.

9. Potentially free energy supply if you are using solar panels, wind turbines, or Electric Vehicle Charging Stations.

10. Low running costs due to low maintenance.

11. Environmentally friendly with zero carbon emissions.

11 Cons for Battery-Powered Generators known as Portable Power Stations

1. Batteries are very sensitive to temperature and prefer to charge and discharge between 41°F and 113°F (5°C and 45°C)

2. Size: the more output power, the bigger and heavier the unit gets, and it gets very heavy very fast.

3. They are still much more expensive than conventional and inverter generators

4. They charge at a much slower rate than discharging, i.e. using a battery for an hour requires many hours to recharge it. (This is starting to change though!)

5. You have to plan ahead where you’re getting your next refill of energy. You can’t just empty your batteries without being sure that you have a sunny day for the solar panels or access to 110v outlets.

6. Even small batteries are quite heavy. Remember the weight of that small car battery!

7. Limited storage capacity (you can have as many jerry cans of gas and tanks of propane but you can’t haul around ten or twenty battery packs)

8. Dependence on sunlight during power outages.

9. Power output limited by the size of your inverter even if you have a large battery bank.

10. Batteries performance degrades very fast if they are fully discharged. A fully charged battery is not equal to a full gas tank.

11. Battery-powered generators usually have poor roundtrip efficiency. i.e. you get much less energy than what you put in it.

Will batteries replace generators?

Batteries and their current technology will not replace generators in the foreseeable future as they are still too heavy, overpriced, and take too long to reach a useful charge.

In a battery-based generator, the energy source is the sun or the grid. And the storage receptacle is the battery itself.

In conventional and inverter generators, gasoline and propane are used to produce power, and the energy receptacle is the gasoline jerrycan or the propane tank.

To match a conventional or inverter generator power output, you will need as many batteries as gasoline jerrycans or propane tanks. Batteries are costly compared to fossil fuels.

Now, even if you were to purchase a lot of batteries, you would still be limited by the inverter, limiting the power output. An inverter converts the DC power stored in the battery to a useful 110-volts AC that can power your house. Your power output is as good as your inverter’s output. So if you increase the size of your battery bank, you will have to add a bigger inverter. 

Now all those batteries (jerrycans and tanks) will need to recharge themselves, and they are limited by a certain speed of charge (you cannot fill them up like pouring gas in a jerrycan). You can buy even more batteries to offset the low charging speed, which means you will need even more solar panels (possibly more than the surface area of your roof) to charge all those batteries. Meanwhile, all those batteries are being drained by your home appliances at a much faster rate than being charged. 

Lastly, batteries don’t like to be charged or discharged too fast as they end up overheating, and your charge controller will stop sending energy to them till they cool down!  

What is the most powerful battery generator?

As mentioned earlier, there are many sizes of Portable Power Stations for all sorts of needs and uses. But if we were to try to match the power output of conventional and inverter generators, we would need to look at the most powerful available and tested battery generator.

Currently, the most powerful battery generator (and still somewhat portable) is the EcoFlow DELTA Pro Portable Power Station. It is too good even to describe. So go here to read all about it from its makers.

This kind of expandable battery power offered by the EcoFlow DELTA Pro Portable Power Station will run your refrigerator and your entire house. It will also cost you a hefty sum, so you must be ready to splurge some. The Delta Pro completely charges itself in less than 2 hours and has ALL the options and benefits that come with battery-powered generators.

Can a battery-powered generator (vs. conventional generator) run a house?

A battery-powered generator can run a house. But it is prohibitively expensive and will need ample roof square footage to install solar panels to keep it charged.

A conventional generator will always be better for large loads and high-demanding appliances and for as long as your gasoline stock can last. A power station will generally power a few lights, cellphones, laptops, and a TV and will need at least a day to recharge itself from a solar panel.

So assuming that you need a backup for a power outage, a generator will cover your major needs at home.

Additionally, a Portable Power Station or an Inverter Generator can step in to feed the more sensitive and usually low-power demanding electronics.

What generator size do I need for my house?

A whole-house power backup will require a generator rated between 5000 watts and 10000 running watts. An average of 7500 running watts is recommended as it will simultaneously power your fridge, chest freezer, well & sump pumps, house lights, TV, and charge phones & laptops.

Below, we will compare Conventional Generators, Inverter Generators, and Portable Power Stations for 5000 watts output which should be enough to power your whole-house essentials.

A conventional or inverter generator will always be better for whole-house backup during an emergency or a power outage. Conventional and inverter generators rely on gasoline or propane, usually readily available. A rare case where it would be interesting to have a battery generator is if you live in a sunny area and access to gasoline and propane are an issue.

Batteries are kind of iffy with extreme temperatures, both high and low – they need nice weather! Discharging your Portable Power Station too fast will heat the battery and render it incapable of charging fast enough, if at all, till it cools down (it takes anywhere from an hour to 2 hours). 

Battery generators are typically sized to last a day or two before they require recharging. Batteries, unfortunately, tend to be discharged way faster than getting recharged, which Leaves you with a power gap while the batteries recharge themselves. A conventional generator will keep pumping power to cover all your needs and require minimal downtime to cool off to get refueled.

Finally, remember that battery banks typically need to be replaced as the batteries lose their ability to retain their charge and become very inefficient.

Home backup systems comparison

Conventional GeneratorInverter GeneratorBattery (Power Station)
WeightHeavyLightVery Heavy
EfficiencyLow EfficiencyHigh EfficiencyMedium Efficiency
CleanlinessMessy and pollutingMessy and pollutingClean
PriceAffordableExpensiveVery expensive
NoiseNoisyIt gets noisy at full loadSilent
Power AvailabilityAlways availableAlways availableIt takes a long time to charge
Reliability during blackoutsAlways reliableAlways reliableIt will get drained quickly and leave you stranded
Whole-House CapabilityYesYesYes
PriceCheapQuite ExpensiveProhibitively Expensive
This table compares all aspects of conventional, inverter, and battery generators.

What is a reliable home generator and how to choose one?

A reliable home generator should have:

  • Enough power output (7500 running watts)
  • At least five 110-volt outlets
  • Provide clean power (THD less than 5%)
  • Have a large fuel tank (ideally dual fuel, gasoline, and propane)
  • Be on a set of wheels to quickly move around in emergencies

Other conveniences include low noise level, electric start for easy operation, EFI Electronic Fuel Injection to eliminate the need for a carburetor, and carbon monoxide detection.

If you plan to connect your portable generator to your home, a wireless remote start is a good option, allowing you to start the generator from the comfort of your own home during bad weather.