[ALToronto]

When I charge my Torch 9810 to 100% using a car charger, the charge drops much faster than when I charge to 100% using a wall charger. Anyone else having the same problem? Is it just a coincidence?

[Branta]

Pure coincidence, and probably distorted by the usage of your phone and different radio loading as you move around. In simple terms the phone and battery can't tell the difference between electrons from different sources, the battery is reported as fully (or x%) charged using the same parameters every time regardless of the source when the desired number of electrons have been pushed from the positive plate to the negative plate of the battery. At 100% the charging circuit shuts down - that's the intelligent charging circuit within the phone, the external part is simply a 5 Volt power supply.

The only way the external supply can make a difference is the speed of charge, which is limited by the current rating (Amps or milliAmps) of the supply. That is simply the max charging current it can support, and will only extend the charging time if the supply is less than the phone is able to take. Most times the supply can offer more current than the phone needs, and the phone sets its standard rate. At very low (inadequate) supply capacity the voltage will drop, the phone will fail to charge, and a message usually appears on screen.

[tboyd1120]

Pay close attention to your application updates, I've found that some updates turn on or add features that start raining my battery. Also check the settings on the applications that you use and turn off the features you don't use. Your BB should go all day without a charge.

[T�nis]

While the information in post #2 makes total sense and is completely logical (I'm saying this as a trained electrician), I have also noticed this when I charge in the car. I think it has to do more with the accuracy of the battery gauge and my habits when charging in the car as opposed to at home. Battery gauges aren't always accurate, and (if you're like me), when you're at home, you may have a tendency to leave the phone on the charger longer. When I plug in with the car charger, it's usually for a quick top-off (I might be down to 30% or something), and I tend to disconnect as soon as it shows that the charge is complete. But is it? I don't know. Maybe not if the gauge is inaccurate.

I was reading that if your phone is on, and you leave it on the charger, it might get to 100% and then start to discharge. Whatever is using the power in the moment (backlight, etc) causes this, and is called "parasitic drain" (or "draw" or something like that). When it drops down far enough it will start to charge again. The source I was reading from said that shutting your phone off while charging will avoid this. Maybe it's my imagination, but I think I get the best (longest lasting) charge when I charge with the phone off, overnight. When I charge with the phone on overnight, the charge is good, too, but the other way is slightly better. When I charge in the car, the charge drops noticeably faster. Though I don't know why, I think it's for the reasons I stated: battery gauge inaccuracy and length of charge (disconnecting from the charger fast, as soon as it shows full). But one thing is for sure, car chargers are not bad for your battery.

[mssca]

Buy a good charger. I found the cheap car chargers could create problems. I got one to go on vacation with my good old 9700. Because I am a student, I got the cheapest one I could find at BestBuy. I found that every time a call come in, the charger stops charging. Eventually during the trip the fuse in the charge went out. When I went back to BestBuy, they told be the reason was because I brought the cheapest one and they have issues like this here and there due to quality control.

[T�nis]

Yes, do buy a good one. I got my BlackBerry branded car charger at Staples for $20.

[sam_b77]

Brant's explanation is spot on technically (mechanical engineer here), but I always felt that car chargers destroy the battery. Off late I used my car charger a lot and noticed that my battery started lasting much less. Even when I charged it home at night and unplugged it at 100% the battery would drained by morning when I woke up.
I swapped batteries with my cousin, who had bought the 9900 the same day as I had and immediately the battery drain pattern changed. The battery would fall off only by 10% by morning and a quick charge while got ready was enough to last me all day.

Its not electrons, I think more has to do with the charger itself. The home chargers convert AC to DC so any variations and unclean current is taken care of right there.
The car battery is DC, so the charger is giving straight through DC and only stepping down the voltage. Since the car amperage through the outlet is hardly constant as there is load or no load condtions on the alternator of the car, the fluctuations are then passed on which might damage the battery. It would depend on how the charger is ensuring clean current, but its difficult to clean DC if there are fluctuations present.
Just my theory though from whatever little I know about electrical systems.

[ALToronto]

Thanks everyone. I have the official BB car charger, but the faster drain has been a recurring problem with my previous phones as well. With my old Bold 8900, it got so bad that I would often let the phone shut off than charge it in the car. Only when I absolutely needed to make a phonecall did I plug it in.

I like Sam's explanation of 'dirty' current. I recently bought the MyBattery app, and the charging curve is much smoother with the wall charger than the car charger. I guess it's just something to keep in mind and be cautious about.

[T�nis]

Okay, today, at the end of the day, when I got home my battery was down to 45%. I put it on the cradle, ate, took a shower, etc. When I picked it up after that it said 100%. Now that I've been using it again (not long maybe a half hour), it has dropped radically to 85%. I can only conclude that it's a battery gauge inaccuracy, that it really hadn't fully charged in the short while it was on the cradle even though the gauge said 100%. This never happens when the phone charges overnight.