[gdob]

Hi everyone,

Although I have only been a member of this group for a week or so, I know better than to pose a question that has been discussed in various forums. Thus I searched for information prior to deciding to post the question I am about to ask. I did find references to the issue I wish to discuss, but could not locate a definitive answer. My question regards draining the battery on my new 8700c. On three occasions, I have allowed the battery to run down to the point where network contact has been lost (with approximately 15% charge remaining). I have then recharged the battery. However, although I only make 2 or 3 brief calls (lasting no more than a few minutes) and surf the Internet for about 1/2 hour each day, I find that I have to recharge the battery every few days (I also do not turn off the unit, but allow it to "sleep"). Therefore, I am asking for advice about whether it is best to allow the battery to full discharge. I am sorry to be a bother, but would really appreciate a response. I'll be more intelligent in weeks to come.

[AlbertoM]

The BackBerry 8700 uses Lithium Ion batteries. They do not build a "memory" like the nickel-cadnium batteries do, nor do they need discharging like the NiCads. In fact, a deep discharge is harmful to Lithium Ion batteries - so don't do that.

All that you ever wanted to know about batteries can be found at http://www.batteryuniversity.com/

We all have to recharge the battery every few days - just how long do you expect your battery to go without recharging? This is not a black and white Palm PDA which could go a couple weeks without hitting the charger. The battery is used even when it "sleeps", as you put it. In my case, my battery gets charged every night. I have to sleep anyway, so the BB gets plugged in at my nightstand. BTW, that is another thing with Lithium Ion. You can't overcharge them....


Hope this helps.

[BeetC]

Great post. Iget about a day out of my 7100. and throw it on the charger for the night. The only time the battery truly runs down is wen I have to get up earl for work and I forget to charge it.

[cooperpwc]

AlbertoM, I'm glad you posted this. There has been lots of talk on BBF about the need to do triple deep discharges of the battery, and I don't buy into it. Lithium Ion batteries don't require that treatment.

[delmarco]

When I get home at 8-10 pm every night I get about 75% to 85% left from my 8700g. I find turning bluetooth off and the wireless off when I'm on the subway or at the gym or in class or the movies is better, than vibrate/silent mode.

[gdob]

AlbertoM, I could only get a day or two out of my PDA. And if I pushed on it a little hard, it would break. Then I would have to sharpen it....hmm, sorry I was talking about the pencils that I once used to write with. Sorry for the confusion.

Thanks to everyone for the responses to my question. Now, if I can only encourage my students to be as responsive, I will truly have achieved something. Then again, I need to find a way to convince them that I shouldn't be the only person in the classroom who opens and actually reads the textbook. Ah the joys of teaching at a university.

Have a great evening, all.

[jsuen]

Originally Posted by cooperpwc

AlbertoM, I'm glad you posted this. There has been lots of talk on BBF about the need to do triple deep discharges of the battery, and I don't buy into it. Lithium Ion batteries don't require that treatment.

You only need to do a triple-deep discharge if a Li-Ion has sat unused for a long period and it self discharges. Even if you do that, there's a permanent loss of capacity. That's a guaranteed way to kill a Li-Ion, they need to be used, or at least cycled once a month.

A single full cycle will recalibrate the battery fuel gauge.

I once came across a great page with self-discharge curves and a demonstration of the loss of capacity after storage. It showed that the best way to long-term store the battery was at 50%. I'll see if I can find it again.

[wibbly]

Best advice I can give is

- Charge it whenever you get the opportunity. 'Topping it up' is just fine
- Don't get a spare "just in case" unless you actually use it. Lithium cells degrade no matter if you use them or not.

Consider the battery a consumable. When it does eventually show reduced capacity, just replace it witha fresh newly manufactured one...

And one of the biggest variables to battery life is the proximity you are from a cell tower. A phone may transmit at up to 2W if it's a way from the tower. 100 times less if it's very close. So if home and/or work has a poor signal, expect the battery to go flat more quickly.

[gdob]

And I really did appreciate the help, AlbertoM. In fact, I deeply appreciate the comments from all. As stated, I am a new member of this board, but it took only a very short time to realize the great benefit that is derived from being associated with such a fine group. Thanks to all for taking the time to help.