# Why do I have to charge my new cell phone for 24 hours before using it? **URL:** \ **Category:** Factual Questions\ **Created:** [January 1, 2004, 7:08am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088 "2004-01-01T07:08:50Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [January 1, 2004, 7:08am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/1 "2004-01-01T07:08:50Z")
I received a brand new cell phone today and the instructions tell me to charge the phone for 24 hours before activating it. The phone already indicates that the charging is complete. It uses a lithium-ion battery. So just what is it doing by sitting around on the charger? ---
**Author:** ![Mr.Moto](https://avatars.discourse-cdn.com/v4/letter/m/9de0a6/32.png) [@Mr.Moto](https://boards.straightdope.com/u/Mr.Moto)\ **Post date:** [January 1, 2004, 7:21am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/2 "2004-01-01T07:21:12Z")
It’s watching you. Seriously, though, you have too give a rechargable battery a really good charge the first time, otherwise it’ll only hold a partial charge its entire life. ---
**Author:** ![Mr.Moto](https://avatars.discourse-cdn.com/v4/letter/m/9de0a6/32.png) [@Mr.Moto](https://boards.straightdope.com/u/Mr.Moto)\ **Post date:** [January 1, 2004, 7:25am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/3 "2004-01-01T07:25:15Z")
to give…sorry. ---
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [January 1, 2004, 7:28am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/4 "2004-01-01T07:28:54Z")
Then I shall wait until 6 pm tomorrow to start up the new phone. It’s not like I’m going to be busy. It may interfere with my chips and salsa fest in front of the TV watching football. ---
**Author:** ![pilot141](https://avatars.discourse-cdn.com/v4/letter/p/e0b2c6/32.png) [@pilot141](https://boards.straightdope.com/u/pilot141)\ **Post date:** [January 1, 2004, 7:32am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/5 "2004-01-01T07:32:03Z")
OK, I was going to answer this until I saw that **BobT** said that the phone indicates that charging is complete. I am assuming this means that he unpacked the phone, plugged it into the charger and after some time (less than 24 hours) the charger said “OK”, either by a green light or some other means. He (I think) is asking what is the point of leaving the phone in the charger after the phone itself thinks charging is complete. The “full charge” indicator on phones is (like many gauges) wildly inaccurate. However, the chargers themselves are fairly accurate at determining “full charge”. Thus the question: first time charging, the box shows green, why should I wait? I’m wondering myself now if there is a legitimate reason for it or if phone companies are just covering for the worst-case scenario of battery depletion during transport and storage. ---
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [January 1, 2004, 7:39am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/6 "2004-01-01T07:39:58Z")
I asked this because it’s a lithium ion battery which isn’t supposed to have a “memory” problem. ---
**Author:** ![Quint\_Essence](https://avatars.discourse-cdn.com/v4/letter/q/54ee81/32.png) [@Quint\_Essence](https://boards.straightdope.com/u/Quint_Essence)\ **Post date:** [January 1, 2004, 8:48am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/7 "2004-01-01T08:48:54Z")
Bobt you are correct. Battery “memory” is not really an issue and for that matter, even in older batteries, was not an overly common occurence. The main reason for the initial 24 hour charge is that these batteries only hold a charge about a month if unused, unlike for instance, a car battery or a regular alkaline, which can each hold a charge for several months or longer. The charger/indicator light in a newly opened phone can often show a full charge but when you go to use it it dies quickly. This is because the voltage remains high though much of the current has seeped away. A full 24 hour charge will assure a fully charged battery. If you were to not use the phone again for seveal weeks, even though it was fully charged when you stick it in a drawer or something you would want to recharge it again for the same reason. ---
**Author:** ![Shade](https://avatars.discourse-cdn.com/v4/letter/s/2bfe46/32.png) [@Shade](https://boards.straightdope.com/u/Shade)\ **Post date:** [January 1, 2004, 11:35am UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/8 "2004-01-01T11:35:27Z")
And by “using it” do they mean “making calls” or “disconnecting it from the charger”? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 1, 2004, 12:01pm UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/9 "2004-01-01T12:01:50Z")
> [@](#): > > \*Originally posted by pilot141 \* > \*\*The “full charge” indicator on phones is (like many gauges) wildly inaccurate. However, the chargers themselves are fairly accurate at determining “full charge”./B] In most cases (certainly with Nokia phones), the ‘charger’ is nothing more than a PSU and the charging control circuitry is built into the phone and (I think) is driven by the phone software, so the indicator should be as accurate as you’re going to get. ---
**Author:** ![Vision4BG](https://avatars.discourse-cdn.com/v4/letter/v/b9bd4f/32.png) [@Vision4BG](https://boards.straightdope.com/u/Vision4BG)\ **Post date:** [January 1, 2004, 3:02pm UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/10 "2004-01-01T15:02:19Z")
It’s a catch-all solution. 24 hours should cover any battery they end up releasing with the phone. It’s also crap. Once it shows a full charge, that’s it, it’s full, and it ain’t going to charge anymore. Quit Essence is incorrect. You use it and it won’t run as _long_ as normal, but it’ll still run close to normal. You generally need to use a battery 2-3 times to get it to hold maximum charge. LiIon barely loses charge by the way. I’ve had batteries that are 4 years old still able to hold charge for over 6 months. Mangetout is correct - the charger circuitry is built in to the phone and these days is extremely accurate. ---
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [January 1, 2004, 6:10pm UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/11 "2004-01-01T18:10:21Z")
> [@](#): > > \*Originally posted by Shade \* > \*\*And by “using it” do they mean “making calls” or “disconnecting it from the charger”? \*\* For the record, the manual says not to activate the phone until it has been charged for 24 hours. But since it’s New Year’s Day and there is plenty to keep me not gainfully occupied today (i.e. watching football), I’ll probably leave it on the charger for close to 24 hours anyway. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 1, 2004, 6:17pm UTC](https://boards.straightdope.com/t/why-do-i-have-to-charge-my-new-cell-phone-for-24-hours-before-using-it/222088/12 "2004-01-01T18:17:28Z")
I agree with **Vision4BG** - the 24-hour period is specified so that there is a really comfortable margin of error - the battery might only take six hours to charge initially, or maybe seven, or maybe three, but after 24 hours, it will **always** be fully charged(unless there is a fault, of course).