Understanding Battery Capacity Ratings: Ah vs. Wh > 자유게시판

When shopping for batteries—whether for a cordless drill—you’ll frequently encounter two critical metrics: current capacity and Wh. These values indicate how much energy a battery can hold, but they measure fundamentally different things—and understanding the difference can significantly improve your decision-making.

Amp hours, or Ah, quantify the current delivery capacity a battery can supply over time. For instance, a 8 Ah battery can deliver 1 amp for 10 hours. This metric gives you a rough idea of runtime under load—but it ignores potential energy. A 12-volt battery with 10Ah and a 36 volt 10 amp hour are rated the same in Ah but deliver unequal power levels.

Watt hours, or Wh, measure real energy capacity. It’s calculated by multiplying voltage by amp hours. So, a 12V 10Ah battery equals 120 Wh, while a 36 volt 10 amp hour battery equals 360 Wh. This means the 36V model holds three times the usable power. Watt hours enable accurate evaluations of real-world performance—independent of cell configuration.

Why does this matter? When evaluating power sources, always prioritize Wh if you want to know which delivers more power. Two batteries with matching current capacity but different voltages will perform differently. For example, a 20 Ah 12V battery and a 10 Ah 24V battery both provide 240 Wh, making them equal in capacity despite their radically different Ah numbers.

Some manufacturers emphasize Ah values because the figures look more impressive, but energy capacity are the reliable standard for energy storage. Always check the voltage rating to determine total energy if it’s not listed. Most reputable brands include both ratings, but if they don’t, you can do the math by multiplying volts by amp hours.

In summary, amp hours describe current flow over time, while watt hours reveal actual stored power. For accurate comparisons, باتری یو پی اس always rely on Wh. Whether you’re selecting a battery for your power tool, understanding this distinction helps you choose the right power source and maximize runtime.