[Ptrick]

I'm interested in whether a PCDP that runs on rechargeable Ni-Mh chewing gum batteries has much of a difference in sound compared to dry AA batteries.

Are there any noticeable differences? Any advantages of one battery type over the other?

 

[Joe Bloggs]

You can buy rechargeable NiMH AA batteries too. That ought to cover any differences

Well, dry cells are 1.5V each, while NiMH cells are 1.2V each. So a pcdp running with dry cells may get more voltage and so more power to the headphone amp... for the first quarter of the battery life, maybe??

That's if you're running alkalines--don't bother with zinc-carbon.

 

[jlo mein]

ya alkalines will fade to 1.2v and lower as their batt life dissappears....

personally i just like NiMH's for their convenience....

 

[Eagle_Driver]

And alkalines actually operate near 1.2V throughout most of their usable life. They may deliver 1.5V at the very beginning of their shelf life (but often deliver a bit less than that when you open the package). Contrast that to most rechargeable batteries, which operate near their rated voltage throughout almost their entire between-charges life - and then plummet.

 

[AssafL]

Consider that chewing gum models are usually designed for 1.2V, while replacing a dry cell with a rechargeable one gives 0.3 Volts less per cell. For a 1 cell player that is not much. But for a boom box with upwards of 10 cells, that may be out of specification.

At last a reason not to get a boom box...

 

[fredpb]

Quote:

Originally posted by Ptrick I'm interested in whether a PCDP that runs on rechargeable Ni-Mh chewing gum batteries has much of a difference in sound compared to dry AA batteries. Are there any noticeable differences? Any advantages of one battery type over the other?

PCDP are so bad these days that either battery probably sounds the same, when both are new (newly charged). An end of life alkaline probably will decrease the sound quality. A Nimh or Nicad will die quicker so will give out constant current for most of its charge life. The rechargables will also deliver more current when required, so bass may be improved on a really good PCDP.

Gumstick batteries are about 1200 to 1400mah. A good alkaline is about 2400mah.

Replacable batteries are nice on long trips or wilderness areas.

 

[purk]

According to my experience with Discman, I don't think their is a sound quality when you use the alkaline AA, AA NI-Mh, or gum stick LI-ion and Ni-mh. I stopped buying the Alkaline 2 years ago.

Purk

 

[penvzila]

Quote:

Originally posted by Eagle_Driver And alkalines actually operate near 1.2V throughout most of their usable life. They may deliver 1.5V at the very beginning of their shelf life (but often deliver a bit less than that when you open the package). Contrast that to most rechargeable batteries, which operate near their rated voltage throughout almost their entire between-charges life - and then plummet.

They almost always say 1.5 on my multimeter

 

[Ptrick]

Last night I dug out my old original Ni-Mh chewing gum batteries that came with my D777 in '96. As expected, they were completely dead and drained when I tried them again, and so I charged them... and something quite interesting happened.
First of all it took about 20 minutes to "finish" charging on the discman (D777 charges them inside the player. With my usual pair of Ni-Mh's it normally takes about 1 1/4 hours... but anyway I popped in a CD and listened to them..... and they lasted about 40 minutes.
And so I say "great, maybe they just needed a warm up" and so I charge them again.... but the second time round, after 2 1/2 hours they're still going! and then I say "hang on, what's going on?"... and open the lid and to my suprise, the batteries were HOT! Way more hotter than normal... and so I immediately stopped the charging. I haven't tried out the batteries yet, but this was something pretty weird.
Hopefully I didn't fry them! (If that's possible..)

 

[fredpb]

Quote:

Originally posted by Ptrick Last night I dug out my old original Ni-Mh chewing gum batteries that came with my D777 in '96. As expected, they were completely dead and drained when I tried them again, and so I charged them... and something quite interesting happened. First of all it took about 20 minutes to "finish" charging on the discman (D777 charges them inside the player. With my usual pair of Ni-Mh's it normally takes about 1 1/4 hours... but anyway I popped in a CD and listened to them..... and they lasted about 40 minutes. And so I say "great, maybe they just needed a warm up" and so I charge them again.... but the second time round, after 2 1/2 hours they're still going! and then I say "hang on, what's going on?"... and open the lid and to my suprise, the batteries were HOT! Way more hotter than normal... and so I immediately stopped the charging. I haven't tried out the batteries yet, but this was something pretty weird. Hopefully I didn't fry them! (If that's possible..)

Normal behavior for batteries, especially nicad and nimh.
Many manufacturers state that you should fully charge them before use. And of course, they need "exercise" for full capacity.

 

[martioz]

They getting hot during charging, this is normal symptom.
If the temperature is below 45C you don't need to worry, if above you have problem, probably with the charger.
Certain type of Ni-Cd can be use up to 80 or more degree.

 

[phasefour]

Quote:

Originally posted by fredpb Gumstick batteries are about 1200 to 1400mah. A good alkaline is about 2400mah.

whoooooa how does an akaline get 2400 mah?!

 

[AssafL]

AA Alkaline is 2400mAh. But only for low discharge rates!

 

[fredpb]

Quote:

Originally posted by AssafL AA Alkaline is 2400mAh. But only for low discharge rates!

This is true. For a high drain device, as the battery ages, the internal resistance goes up, and it can't supply the current, so a high drain device won't get it's current and will say the battery is drained, when on another device of lower current drain the battery may have half it's capacity left. This is for alkaline batteries.

Now Nimh or Nicads operate at a slightly lower voltage, but will pump out amazing current until exhausted. If you want performance from very high current devices, like digital cameras or photo flashes (faster recycling time with rechargables), you need the nicads or nimh. There are also a few special batteries that will deliver more current and are alkalines, but I forget the name, and there are also lithium batteries too.

 

[martioz]

You can get lithium-iron batteries with 2800mAh and 1.5V for low current application only

They come in AA size mainly for metering eqpt.