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I was doing some energy calculations for my senior design class, and for some reason ... BlackBerry Bold forum

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    gatechfireblade's Avatar
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    Potential reason for varied battery life?

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    I was doing some energy calculations for my senior design class, and for some reason this thought occured. I know most of us that have the bold upgraded from a previous device. That being said, I know at least some of us are using our old chargers, including myself. Well I came home and compared the current and evidently the older charger I had from my curve delivers a higher current (an extra 50 mA). Well that got me thinking. From an energy standpoint, the total power of the battery remains consistent and proportional to the voltage and current.

    (1) power (watts) = voltage * current
    (2) Battery Energy = voltage * mAh (watt hours) * 60 * 60 / 1000

    Using 1, you can calculate the power on the expected voltage and current. Use that power to calculate the reduction in voltage because the current of the other charger is greater. Use 2 to calculate the energies of each system and you get roughly a 8% decrease in energy. Now this is all assuming the blackberry charges each battery fully, but I don't know how the blackberry assumes the battery is charged before it stops charging. It very well could not be charging the battery all the way because of the increased current flow also. I am not an EE, so I very well could have made some assumptions that don't hold true, but its just a thought. Any EE's wanna chime in?
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    betavirus's Avatar
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    The BlackBerry does not control the charging, it is a function of the battery.

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    gatechfireblade's Avatar
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    Quote Originally Posted by betavirus View Post
    The BlackBerry does not control the charging, it is a function of the battery.
    Are you sure? I was almost 100% positive that the blackberry has an overcharge protection function that stops the charging to protect the battery. This is also the same reason why the saying of not charging your battery overnight is no longer correct. I would be amazed if a high end device such as this did not have this feature considering a few of my nokias past had it. Not to mention there is a bedside mode built into the blackberry. To me this would mean that they figured people charge their phones at night so it would be stupid on their part to not have this overcharge protection in place.


    EDIT: Also the charging thing is secondary. It was more the amount of energy stored in the batteries that is different based on the amps from the charger.
    Last edited by gatechfireblade; 02-06-2009 at 05:41 PM.
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    Very well thought out and logical thinking gatech. This definately could be a contributing factor. Also the difference in chargers, devices and even the batteries themselves could also be factors. One thing is certain, the Bold puts a great drain on the battery. ~via 9000~

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    Dont forget to input, talk time, data transfer time, bluetooth on/off/transferring time, camera flash, media card browsing, graphics statistics (animation + webpage browsing + themes + and applications) then of course speaker volume and usage, GPS, and of course you cant forget OS..... um forgot scrolling activity, backlight, keypad light and keypad button pushing..

    I can drain a battery dead in about 2 or 3 hours, using nobex, to stream radio, bluetooth head phones (though i wonder if the bluetooth drain is more then the builtin speaker?) and playing games or browsing the web at the same time.

    Factory battery of course,
    It takes many professionals versed in many different area's to help the masses, I am just a single drop in that pool.

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    ~via smartphone~

    If I have media, Bluetooth, and wifi off, I can use 75% of my 8120's OEM battery in a day playing games, the occassional phone call, and chatting and surfing. If I use the media player I use 80% of the battery.

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    I completely understand that other factors play into the battery issue and I stated that this particular issue is ONE possible reason of the many, and can be fixed universally. I am not saying this is the only reason. There are way too many variables between people and how they use their blackberries. A comparison of the same person with different OS is just as bad. No one's usage is the same from day to day. All I was proposing is whether this makes sense to all the technically inclined people.
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    Yes, for sure this theory makes sense. I think your ? Is right on the money as to how the bold knows the batt. Is fully charged. If its a case of reading voltage in the batt then I would say using a charger that has more current could very well not be charging the batt all the way. If that's how it knows it charged. Very interesting. I will have to dig a little deeper into this myself. I personally don't use a wall charger, just usb. I curious now how it works. Once my hangover is gone I'll get out of bed and try to find out how the bold knows when its fully charged. ~via. Almost dead battery bold

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    Also you have to take in consideration if you are using a oem charger they have built in chips that stop the flow of energy when your battery if fully charged at least in car chargers.~via smartphone~

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    So I can confirm that the blackberry does have a play in charging. I was exploring the engineering screens and there are settings that detec whether its attached to usb or ac and adjust current flow accordingly. The confusing thing about this, is that you can see what the settings are for each type of charging. Well, for AC charging its set at 1350 ma, which is weird because the charger only allows 700. Hmm....
    Last edited by gatechfireblade; 02-08-2009 at 01:56 PM.

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    Well I don't think that you can setup some formulas to get how long a battery could live.
    You're having a lot of issues that could increase the time:

    1. The coverage
    2. Do you have aditional features running like WiFi or Bluetooth
    3. How many SMS or mails do you receive or send
    4, How many calls do you do or receive?

    And some things that you never be aware of:

    5. The SIM. Cause older SIMs need more power than newer ones.
    6. How did you charge the battery? Cause the battery is like an living object. You can teach it.

    My 2ct
    Peter

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    I get it. I know there are many variations that can impact a battery, but the battery itself can be something that could be changed as to where you might not want to sacrifice a program/mode/feature. A battery well cared for, charge correctly, and in good condition will give you more power despite all the other factors. Making sure you are getting a good initial charge, using the right charger for the battery(Not one from another BB...they are made in diff. countries.), and keeping it charged frequently. (Which is the best performance level for a Lithium Ion.) Abuse can ocur during initial use w/under-charged batteries, extreme temp changes, and contact w/foreign substances...yes H2O, soda, coffee, etc.

    Good insight! Nice post.

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    Interesting thread, I like scientific stuff. Doesn't the Bold use microUSB though? If so I doubt if anyone can even use their old AC chargers for it (unless they bought adapters). Correct me if I'm wrong but isn't the best practice to fully charge the battery (using OEM AC charger that comes with it) then discharge it almost fully a few times before using something like a bedside dock or plugging it in every night? Or can you just top it off all you want from the get go? I'm getting an 8900 soon and they claimed they fully charge it before they send it out.
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    Quote Originally Posted by TheBigNewt View Post
    Interesting thread, I like scientific stuff. Doesn't the Bold use microUSB though? If so I doubt if anyone can even use their old AC chargers for it (unless they bought adapters). Correct me if I'm wrong but isn't the best practice to fully charge the battery (using OEM AC charger that comes with it) then discharge it almost fully a few times before using something like a bedside dock or plugging it in every night? Or can you just top it off all you want from the get go? I'm getting an 8900 soon and they claimed they fully charge it before they send it out.
    The first initial charge is most important, but Lithium Ion Batteries can take the frequent charges unlike the old NiMh or NiCd. Lithium Ions are also considered a "smart battery".
    They can prevent over-charging by disconnecting when full charge is received. This is why one sees the charge symbol(yellow lightning bolt over battery status.)when charging, then later you check your BB and the symbol is gone and the status bar is full. "Topping" a LI battery is preferred, but it is built for use and abuse.

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    Thank you jbee. People clearly are not understanding the point of this thread. I KNOW there are plenty of things that affect battery life. I'm not expecting this to be a solve all solution. I just wanted to run my thought by some people who may have an electircal engineering background. I'm a mech eng., so I don't know a lot about the topic.

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