Battery size is a more precise measurement, and it helps you determine much more about your machine.
1. Size Helps Determine Energy Efficiency
There is more than one way to make a laptop that lasts over ten hours. One approach is to cram as many battery modules into a laptop’s chassis as it can possibly hold. Another is to see how long you can get a smaller battery to last.
A laptop with a 40W battery uses fewer than 4W per hour to last for over ten hours. On the flip side, a laptop with an 80W battery can last for over ten hours, even if it’s drawing 7W of power.
Seeing on a box or website that a laptop lasts over ten hours doesn’t tell you how much energy it uses. But if you know the laptop’s battery size as well, then you can do the math and work out the efficiency.
2. Battery Size Impacts Electricity Usage
Having a smaller battery means you use less electricity each time you charge your computer. It’s pretty straightforward math. If your laptop has a 30W battery, that’s how much energy you draw whenever you charge it from empty to full.
To see the impact on your electric bill or battery bank, you may need to convert this number into kW. There are 1,000 watts in one kilowatt, so 30W = .03kW. If you’re paying 12 cents per kilowatt, then this adds up to .36 cents per charge.
.36 cents doesn’t sound like much, and it isn’t. Even if you drain and recharge your laptop daily, that only adds up to around 10 cents a month. But there are other factors to consider too. For example, a laptop with a smaller battery may have a less power-hungry CPU. This means your computer doesn’t merely use less electricity to charge, but it uses less electricity to function.
3. A Smaller Battery Is Easier Off-Grid
A laptop with a smaller battery is easier to take off the grid for the simple reason that it draws less power from your batteries. Every watt matters when trying to live off solar panels or stretch how long a portable power station lasts.
If you don’t need the extra power, a weaker laptop with a smaller battery can still enable you to check email, draft documents, and manage finances without putting much of a burden on your off-grid power system.
Laptops consume relatively little power compared to other electronics, so this may encourage you to move more tasks onto your PC. Can one function as your off-grid TV? It sure is easier to carry around.
4. More Recharges From a Portable Battery Bank
Even if you don’t live off the grid, there are still advantages to having a computer that puts less strain on an external battery pack. These days, portable battery banks that can power laptops are easy to find, just like those intended for phones and tablets. But your laptop’s battery is much larger than that of a phone, and you may find you can’t even fully charge your laptop if it has a massive battery.
Consider how a 100W battery bank can recharge a laptop with a 50W battery almost twice, one with a 75W battery 1.5 times, and a laptop sporting a 100W battery only once. A laptop with a 30W battery can get closer to three charges.
5. A Bigger Battery Usually Lasts Longer
There are advantages to having a smaller battery, but there is a reason many laptops come with bigger ones.
If your goal is to go as long as possible between charges, a bigger battery helps. After all, it’s easier to get longer battery life out of a laptop with a big battery, regardless of how energy efficient your machine is. Plus, if you know you have a large battery and can throttle your CPU or use other power-saving methods, you may get more than the advertised battery life out of your device.
MacBooks with Apple Silicon CPUs pair an efficient processor with a substantial battery pack. The result is battery life that puts most of the competition to shame. You may not be able to fully recharge one of these machines with a smaller battery bank, but you may not need to. If the laptop can last multiple days on a charge, recharging only halfway can buy you another day.
6. A Bigger Battery Means More Power
There’s little point in making a beefy laptop with a small battery. It won’t hold a charge long enough to be considered portable. Maybe you can move it from one desk to another without it dying on you, but that’s the extent of it.
If you want a laptop that can play the latest games or compile video, you likely want one with a bigger battery. Sure, the size of the battery doesn’t tell you how much power a PC is packing. That’s what other specs are for. But if you’re comparing different models, you may notice a correlation between processing power and battery capacity. A bigger battery can support a heavy power draw longer than a small one can, long enough to make a powerful computer viable as a portable one.
Which Battery Size Do You Prefer?
If you’re comparing two identical machines, except one has a larger battery, then the decision is a no-brainer. But that’s likely not the case. A smaller battery might mean a smaller, more portable laptop. A bigger battery can mean a more powerful one. Which matters more to you depends on your preferences and your needs.
