Do battery hours affect power in a power tool?

The characteristic of a battery is described in Ampere Hour or Amp Hour.The capacity of a battery is referred to as this.

A 5Ah battery will power a 5 Amp device for one hour.This is not correct.

The technical specification sheet is where you will find this on a good quality battery.A sealed lead acid battery specification could look like this.

The temperature of the environment in which the battery was tested is the first thing we are told.In very hot or very cold environments, batteries perform better at room temperature.A battery that was tested at 41F (5C) would be a better battery if it could provide the same capacity, but in hostile conditions.

Sometimes manufacturers prefer to show the data in a different way, for example, stating how long it takes the battery to go from a full charge to a low one under different rates of discharge.The first row of the table could be written.

If you divide the Amp Hour figure by the hour rate, you can see what device the battery can power.

A straight line on a graph can't be made from the relationship between the devices and how long the battery lasts.If we connected this 4 Ah battery to a 0.4 Amp device, it would last around nine hours, not ten as might be expected.The discharge time doesn't decrease to four and a half hours if the device is doubled to 0.8 Amp.

Most batteries don't like discharging fast.The higher the discharge rate, the greater the internal resistance inside the battery which causes it to waste energy and shorten the time it takes to power the device.

The Peukert's Law calculator can be used to calculate the expected life of a battery.A graph like the one below is included in a technical specification sheet with most good quality batteries.

When connected to a 12 Amp device, the battery will last about 40 minutes before the voltage drops below 10, at which point the device will probably cut off.It isn't the one hour that many people think.

Some graphs use C instead of A.C is the same as Ah.For a 12Ah battery 1C is 12 Amps.The graph above shows how we would replace 12A with 1C, 24A, 2C and 36A.

The industry standard is 20, but that doesn't mean all manufacturers follow it.If a manufacturer decides to use a 10 hour rate, it will produce a battery that is inferior to a 4 ah battery.

It is important to be aware of the fact that batteries degrade as they get older and the more they are used.A brand new 4Ah battery might be able to power a 0.2 Amp appliance for 20 hours, but one that has been discharged many times will not last that long.