Battery LifeI

[coachd.2]

I bought a dell pda earlier this year and the battery goes dead evenwhenI don't use it.
I own a palm III which I loved for the functionality but it died.
I am now considering a choice between the T/E or a Zire 21. I need the calendar/contact/spreadsheet/powerpoint functions. If I only turn it on and off to record notes or look at appointments how long should the battery last? My palm III would give me 3 weeks.

[rick417]

I have been running my own little non-scientific experiment on the battery strength of the T/E I have. I have not had it on the charger since Sunday afternoon. All I've done with it is leave it off, and let it perform it's daily backup and any calendar events that are sync'd to it. That's not many. I have been doing a sync almost daily but I missed last night. I also played a few minutes of lemonade tycoon yesterday. My batter level, while I don't see a percentage, is still holding at what appears to be between 3/4 and 7/8 full.

To help lower battery drain from screen brightness, I've installed Energy Dimmer and set the display to around 25% brightness, which dims even further to 10% brightness after 5 minutes, and then goes off after 15 minutes of non-use.

Oh, and I also have Keylock activated and turned off IR receive.

I'll try to remember to post and let you know how long it takes to drain down to the battery low warning.

[mpholic]

My wife's T/E after 4 days of average to above average use (no games, no mp3s, no movies, just pda stuff) was at about 40% so I would think you could get about a weeks worth of average use without recharging.

I don't think battery would last 3 weeks even if you never turned it on. The big difference is the old palms had NO backlight and a processor that ran at 16Mhz. Now you color backlit screens that run at 126 or 144Mhz (some even run at 400mhz).

[rick417]

Over a week now without recharging, although with minimal use (see my post above), and the battery is around 50% discharged now. I'd say the T/E provides adequate battery reliability as long as you take screen brightness and auto power-off precautions...and provided you don't get one with a weak battery, which is luck of the draw off the shelf.

[palm boy]

If you want to do power point and word, DON'T GET THE ZIRE 21!!! It has no color. color makes a difference.

[knightsog]

I've had my T/E for just shy of a month and I absolutely love it!.
That said, I use it most everyday (including weekends) and a workday involves probably 2hrs use. When I first got it I spent 2 hours continuous with it to see how long and it was down to 25% by that time. Other threads have said great battery time and others, like me, say BS. I keep mine on the charger at work and at home. Seeing as Palm has yet to market the charger for this thing I have to take it back and forth to work.
Personally, as a guy with advanced training as an electronics technician, I fail to see how a battery can discharge when the unit is not on if their is no source of power drain. Also, speed of the processor has no more or no less demand on battery power. There are no moving parts, like in a car, so there is no effect.
This is my fourth palm and I consider it to be the best yet. It's fast, versitile and I recommend it highly. I carry around frequently updated MS Office files so I don't have to be at the PC, I have photos of my life, and tons of notes and reminders for my feeble old brain.

[Telyx]

It sounds like you might have gotten a bad battery in your E. My first one would drain from 100% to 40% overnight with no usage at all, so I exchanged it and this one will go all day (moderate use) at 100%. Exchange yours if you can.

As for "Also, speed of the processor has no more or no less demand on battery power. There are no moving parts, like in a car, so there is no effect," that's not true--the faster the processor, the greater the power requirement, assuming the same basic processor architecture. Whether or not it has moving parts is irrelevant; the processor performs more calculations per time interval and that takes more electricity per time interval than a slower processor would.

[knightsog]

Living in Japan I cannot go to a local distributor for unit exchange, which is one of the reasons why I've been trying to call Palm to attention on this issue. Not like their old time customer support, is it? I have gotten no replies to my three requests for assistance to Palm on this. And as I recall, in another thread you stated that you had someone else buy one, he gave it to you and you gave him yours and he exchanged it for a good one, for whatever reason. Or something along those lines.

And who's to guarentee that the one you exchanged for won't be any better than the original? I think you got lucky.

Think outside the box, for a second. Are you aware that the U.S. Government (read U.S. Military) buys a butt-ton of Palms for their employees'/service members' use every year? Not all of those folks live in the United States (duh!). We use our palms (mine happens to be personally owned because I don't want to fall under the restrictions of gov't-owned palms) as part of our jobs and giving them up for two months for a recall won't work.

The bottom line is this: Palm should be aware there is a problem with their batteries (and as such, with the folks who supply them) and make a concerted effort to correct the problem. They should also inform (issue a recall notice?) registered users of the problem. This should involve a battery repair/replace program that could be done by the user without voiding the warranty. (And think what that would do for the sale of the teeny-tiny torx tools required to access the innerds.)

As for the power thing, I agree that more calculations per micro-nano second will require more energy, but that energy drain is relative and minimal. Actually, microprocessors have very little load thus current drain. Not being an engineer I would speculate that the microprocessor's load results in well less than one percent of total battery drain. (PC's still use the same 5VDC power supplies to drive their PIV processors as was done with the 286 or older models. As a matter of fact, they use even LESS voltage thus less current.) The main purpose of the power supply in a PC is to drive all the motors it takes for the drives installed.

The main drain on these things is the display: illumination, color, etc. If you were doing calculations with this microprocessor without any display the battery would last for years. Look at the battery in your watch. Mine is analog and has digital functions as well. But a battery (what? 1.8VDC?) still lasts me three years. (I love this watch. Shop owner says it's old and I should get a new one...that's how wives are replaced, not watches. :-)). The reason I get so much life out of the battery is that I use no alarm functions nor internally-available illumination.

[Hawking]

Also remember that when a PDA is off, it's not really off. They are never off, they just go to 'standby' mode. The screen does in fact turn off. Even with the screen off all of the time, I doubt any unit currently on the market would last more than a month. I charge my T/E every day, but I use mine all day every day. I don't expect the battery to last for very long under this kind of use, but that just gives me an excuse to keep buying new PDA's ;)

-Hawk

[Telyx]

Knightsog, I forgot you live in Japan. Sorry... Judging from the number of complaints about battery life (not "it won't last a week," but "it won't last two hours") maybe I did get lucky. Palm should have a better grip on quality control than we're seeing lately, with Tungsten E battery life, TIII SD card problems, etc.

As for the PC power requirements comparison, remember power = volts x amps. While newer processors may run at lower voltage, there's a reason why their heat sinks have gotten bigger and they have cooling fans. Amps... processors run at a low pressure but a high volume, you might say. Whether you're running a few electrons through at a high speed or a lot of electrons at a low speed, that's still a lot of electrons per nanosecond, and they have to come from somewhere.

[Fusion]

My own experience... About 4 hrs! Buy the Belkin USB car adapter Best Buy, 19.99 or http://www.styluscentral.com/12volusbcaba.html 7.99!!

http://www.theregister.co.uk/content/68/33377.html

Battery
The Tungsten E's one flaw is its short battery life. Palm claims four days' average usage between charges. Using the device fairly intensively during a 24-hour period saw the charge drop to a third of capacity (33 per cent). By contrast the Tungsten T3 fell to 34 per cent during the same period - we were using both devices in parallel - and that had Bluetooth switched on during the period. Both PDAs were set to maximum screen brightness.

We should point out our measurement of battery life was by no means scientific - especially when it's impossible to turn off the auto-power off function - but we think it gives a taste of what to expect. A slower CPU the E may have, but it doesn't offer significantly longer battery life as a result. The E is significantly lighter than the T3, and we suspect simply uses a smaller battery, hence the shorter operational duration. Certainly the T3 Li-Polymer battery is rated at 900mAh, while the E's is just 380mAh

http://reviews.cnet.com/Palm_Tungsten_E/4505-3128_7-30557629.html

As for performance, our unit worked well with Kinoma video files, and MP3s played smoothly. Battery life was decent; in our standard lab test, we were able to run an MPEG-4 file in a loop for 3 hour, 30 minutes. With normal usage patterns, Palm says the E should go for about a week before having to recharge.

[Scott777]

I think really the issue is the battery's reporting to the OS it's voltage and/or percent discharged. Especially when it was brand new. I noticed in the beginning it seemed that after just a few minutes of use, it would show 90%, 80%, etc. After having it a couple of weeks I now notice that it seems to take almost an hour of continuous use to see it dip below 100%. Being a Li-Ion battery, that's to be expected.

I had the opportunity to compare a Sony T35 and the T|E before I committed to the E. I looped a Kinoma movie for 3 hours 15 minutes on the Sony, and got 3 hours 50 minutes on the E. I had both Brightness settings at medium (and the E's picture at medium is MUCH better).

One thing though, at 14% the E stopped the movie but still gave me another hour of play. I just wish there was some way to change the warning to a percent of say 5 or 10 percent.

[Fusion]

I just emailed PalmOne about the battery in the T|E.

"...the E is powered by a built-in rechargeable Lion-Polymer cell rated at 3.7 volts. The battery of the E has the capacity to deliver 900mah."

My previous post said 380mah.

:rolleyes:

[southernbills]

FWIW, I have found that with moderate use, the battery goes down around 25-30% within 2-3 days. I have also found that if you leave it hooked up to the USB cable, it will trickle charge back to full strength in a couple of hours. I have installed FileZ which includes a % battery meter to get a better read on the battery strength.