What does battery ah mean?
3 Answers
Battery ah refers to the capacity unit of a battery: ampere-hour, which is the product of discharge current (ampere A) and discharge time (hour H). When a battery undergoes constant current and constant voltage charging, and then discharges at a constant current, the amount of electricity discharged represents the battery's capacity. Ah is applicable to storage batteries, nickel-metal hydride batteries, etc., but not to lithium batteries. Lithium batteries have a minimum discharge voltage, meaning the discharge voltage cannot fall below 2.75V, typically with 3.0V as the lower limit. A battery is a device that contains an electrolyte solution and metal electrodes to generate electric current, converting chemical energy into electrical energy, housed in cups, tanks, other containers, or partial spaces of composite containers.
This 'Ah' refers to ampere-hour, simply put, it's the unit of battery capacity, just like a larger cup can hold more water. When I repair cars, I always explain to car owners, for example, 60Ah means the battery can steadily output 60 amps of current for 1 hour, or 30 amps for 2 hours. If you're adding a car fridge or high-power audio system, you need to check if the Ah value is large enough. Lead-acid batteries typically range from 45-75Ah, while new energy vehicle battery packs can easily reach several hundred Ah. Here's a lesser-known fact: high temperatures in summer can accelerate water evaporation in the battery, potentially reducing capacity by 15%, so don't just look at the nominal Ah value—regular maintenance is key.
When I bought an electric vehicle back then, I specifically researched the Ah parameter. For example, a 72V20Ah battery pack means it can discharge at 20 amps for 1 hour. In terms of range, it can run about 80 kilometers at a speed of 40km/h on flat roads. However, when climbing hills or carrying heavy loads, the actual range may drop to 60 kilometers. Nowadays, the new blade batteries can achieve capacities of over 150Ah, but the key is still the battery type. Lithium iron phosphate (LFP) batteries have more stable Ah performance compared to ternary lithium batteries, with less capacity shrinkage in winter, which is why I ultimately chose LFP batteries.
