i have some strange questions about my new laptop battery here. I know that two measures that used to state the power rating of a laptop battery is capacity and voltage, but i don't know the whr. I found the 56 whr printed on my battery, and i wonder How long is 56 whr last? Is that a 5-6 hour battery?? the battery detail:http://www.batteryselling.com/compaq-presario-cq62-battery-6-cell-5200mah-10-8v.html, but i can't find anything related to the whr on this product. What is the WHr stand for indeed? how long will these lithium ion batteries hold a charge. Does the bigger number mean the longer run time, thanks very much!!!
Watt hours are a measure of power over time and is a measure of capacity. If the laptop is pulling 56W it would last an hour. If it's pulling 5.6W it would last 10.
The amount of power drawn will vary drastically between idle and full load, different power states, wifi being active, screen brightness etc. The capacity only affects the maximum and minimum run time, which will vary by several hours. and in no way does the W/H tell you what that's going to be
Judging by your question i'm going to go under the assumption you have an average level of battery understanding.
Watt hours(WH): It's not a standardized measurement unit so your not going to see it everywhere. You are far more likely to see mah(milli-amp hours) It's the total amount of electricity that you can pull from the battery. 1 WH is the amount of energy it would take to provide 1 watt of energy for an hour. 10 WH is 10 watts of energy for 1 hour. 10WH is also 1 watt over 10 hours, or 2 watts over 5 hours. To answer part of your question, yes, the bigger the number the longer your battery will last.
It's impossible here to say how long that will last. There are far too many variables. Various things that will affect your battery life are screen brightness, wifi on/off, plugged in peripherals, battery age. Even the temperature of your room will affect your battery life.