mp3 quality and battery life

cosmic_surfer

hi all,

just a quick question...

i just got a portable mp3 player, just a small 1Gb thing. The spec states a battery life of up to 15 hours. However, having used it over the past few days i've found that a battery is only lasting about 2-3 hours.

The mp3s i've been using are ones i've ripped from my cd's, and i've ripped at 192kbps. Is it true that playing higher quality mp3s like this will use up the battery quicker, i.e. if i was to rip at 160 or 128 kbps i would extend the battery life of the player?

Many thanks,
Cosmic

padzster

Are you recharging before it's fully discharged? Some battery types lose their capacity if you do this.
I can't imagine why higher quality files would use up more battery power - at the end of the day you're just playing files and the higher quality ones are just larger in size with more data. The mechanics of the device will still be working in the same way. Correct me if I'm wrong someone!
Can you buy spare batteries or is it all built-in?

jmarko

i would imagine that larger files would use up more battery because they will require more processing by the unit. if you drop the quality to 112kbs you almost certainly won't notice the difference (unless you're a bat) and you'll be able to get twice the amount of music on it! if you're using it for spoken word, you can drop it right down to the 30's or lower and it'll still be fine. and your batteries will last longer.

jmarko

cosmic_surfer

cheers for the quick replies folks!

The player takes aaa batteries, i've used 2 'normal' ones, and am now onto rechargeble ones.

Might just try ripping some lower quality files and leave it playing, just for a comparison on battery life (and sound of course).

Cheers!

bencallis

Hi cosmic surfer can you tell me your results?i have just bought a mp3 player aswell. And am looking or a decent rechargeable battery for it. I know it will need to be how powerd but can anyone point me in the right direction. Thanks.

What mah (in aaa) would roughly work out at alkline proformance. The higehest i have seen is 850mah

Dark_Forces

you can get batteries upto 2500mAh but they can be really expensive. 850mAh will do just fine and should not be a problem. Just get a pack of 4 batteries, charge them all up and use them up one by one, then charge them once they all run out. Thats what I do. Saves me money in the lon run.

bencallis

No i am after aaa not aa and aa seem to only go upto 850 the smallest ones are 250 so 850 seems ok. But as a standerd battery is 1.5v and a recharageable is 1.2v will it still power up?

djohn2002uk

Get the highest capacity (mAh) you can, this represents the amount of charge it will hold and therefore the length of time your player will run for.
If you measure the voltage of your rechargeables with a digital voltmeter when fully charged you will probably find they will be between 1.3v and 1.4v and your player is probably designed to operate down to approx. 1.1v so you should be ok. The difference with rechargeables is that their voltage doesn't drop of gradually like an Alkaline, but will stay roughly at between 1.2v and their "freshly charged" voltage untill there is little of their capacity left and then the voltage will drop rapidly.
One other thing to remember, if you buy NiCads you must completely discharge them before recharging as they have what is called a "memory effect" and the capacity will rapidly drop. This is not the case with NmH.

bencallis

There are some 900mah but they are basicly an unbranded make , would it be better getting say a 750mah which are a good make or some unbranded stuff. By the way im looking on ebay.

Rave

bencallis, the unbranded ones will probably be fine. for NiMHs on ebay there's a seller called vapextech (or similar) who is apparently good (although I've yet to buy from him personally).

djohn2002uk wrote:

One other thing to remember, if you buy NiCads you must completely discharge them before recharging as they have what is called a "memory effect" and the capacity will rapidly drop. This is not the case with NmH.

Nope.

http://www.dansdata.com/gz011.htm

As for the original question- a higher bitrate file needs more data to be read from the memory, so I guess that uses a bit more power.

djohn2002uk

Well Rave, I'm not going to get into an argument with you except to say I speak with experience of a throughput of over 50,000 NiCads per year with a view to recovering them from the memory effect. More than 60% were recoverable through a three cycle charge/discharge process and the rest were disposed of as being naturally at the end of their useful life. These were batteries that had been inserted into a charger daily after 8hrs regardless of the actual state of discharge thereby causing the memory effect.
You follow Dans advice if you wish, he seems to spout on about lots of things but with no great knowledge of any of it, Jack of all trades and master of none comes to mind.