[shimage]

Quote:

Originally Posted by oneeyedhobbit Precisely the opposite. I don't pretend to understand the technicals, though--I'm just repeating what I heard. It was explained to me that rechargeable's don't hold a steady 9volts, they (even Plainview's) drop below this when a certain % of the battery is depleted. Alkaline's, conversely, hold their charge until they are near dead.

It'd be pretty simple to test this out yourself. All you need is a voltmeter, a load, and a few batteries... Plot voltage as a function of time.

 

[bLue_oNioN]

Quote:

Originally Posted by oneeyedhobbit No there isn't. Consumer Reports has done several studies on this, and found that you get marginally longer battery life with a name brand battery (let me stress that marginal bit, not worth the price), but there is otherwise no difference (in voltage, etc.). Further, I've actually heard some say that standard alkaline's sound better than rechargeable's, as they hold the same current for longer, while rechareable batteries drop their current.

oneeyedhobbit - Please refer to the following link.

http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

As is apparent from the results, different battery brands advertised at the same ratings do not perform the same.

For example, the iPowerUS 2100 is trampled by the Energizer 1700.

Test methodology provided rather stressful loads (the top dog hardly lasted two hours) to simulate intensive snapshot sessions. In reality, loads created by portable amps would most likely be substantially less, resulting in appreciable stretches of winning margins.

These battery cells are all available at cheap prices if you look hard enough. But as illustrated by the evidence, you won't always get what you pay for.

If I'm going to spend money, I would want the best bang for the buck. Wouldn't you?

 

[bLue_oNioN]

Quote:

Originally Posted by oneeyedhobbit Precisely the opposite. I don't pretend to understand the technicals, though--I'm just repeating what I heard. It was explained to me that rechargeable's don't hold a steady 9volts, they (even Plainview's) drop below this when a certain % of the battery is depleted. Alkaline's, conversely, hold their charge until they are near dead.

oneeyedhobbit - Please refer to the following link.

http://www.reactual.com/metaefficien...batteries.html

From your references to "alkaline" batteries as a seperate deal from rechargeables (although I do not understand why you exclusively do so since there are alkaline rechargeable batteries readily available), I assume your idea of "rechargeables" are the more prevalent Nickel Metal Hydrides, or NiMHs.

I quote:
For most high drain electronic applications NiMH batteries are ideal substitutes and you needn't worry about the apparent voltage differences. Even though alkaline batteries are rated at a nominal 1.5 volts, they only deliver 1.5 volts when they are fully charged. As they begin to discharge the voltage of alkaline batteries continuously drops. In fact, over the course of their discharge, alkaline batteries actually average about 1.2 volts. That's very close to the 1.2 volts of a NiMH battery . The main difference is that an alkaline battery starts at 1.5 volts and gradually drops to less than 1.0 volts. NiMH batteries stay at about 1.2 volts for most of their discharge cycle.

 

[photographlondon]

Quote:

Originally Posted by Jahn What the? But I swear my ears do not deceive me when I'm listening to an album on auto-repeat and it starts crapping out on me more than an hour before the batteries go kaput. Who knows, maybe the SR71 is so efficient that it eeks out power from the duracells until it hits that 3.5V threshold about an hour before they die.

Here's what Ray said on the subject:

I do not agree with what you mentioned regarding the Alkaline being best when they are fresh & quality of sound drops when they are down in voltage, may be in different components, but let me state this clearly that the Emmeline SR-71 works the same way & with the same quality of sound when the Alkaline are new at 9VDC all the way down to less than 3.5VDC with out dropping the quality of sound or reduction of volume at all. when it stops playing, that is the only time you would think to change the battery. The LED stays on a little longer then it goes off.
Ray Samuels


Here's the link to the thread.

BTW, I'm not trying to prove you wrong or anything - I was curious about this myself and so when Ray posted this information I just thought it was worth sharing. It's possible that at the very end of the battery's charge there might be some degradation but overall you should be fine even with cheapo rechargeables (8.5 volts) - in the SR-71 at least.

 

[Hirsch]

Quote:

Originally Posted by oneeyedhobbit Precisely the opposite. I don't pretend to understand the technicals, though--I'm just repeating what I heard. It was explained to me that rechargeable's don't hold a steady 9volts, they (even Plainview's) drop below this when a certain % of the battery is depleted. Alkaline's, conversely, hold their charge until they are near dead.

This is pretty much backwards. The voltage of an alkaline battery drops as the charge on the battery drops. So, you get a steady decline in voltage as the battery gets used. An NiMH battery has a much shallower decline. The rechargeable will hold a pretty constant voltage until the charge is almost exhausted, at which point the voltage drops precipitously. You can hear this rather dramatically (I wasn't ready for it the first time I heard it, and thought something had broken

).

The Plainviews (and now Maha/Powerex has one) use eight 1.2 v cells in their rechargeables for a voltage of 9.6 volts, which holds pretty steady until the charge is near gone. Most rechargeables use seven cells, for a voltage of 8.4 volts. I'd expect a 9 volt alkaline to sound better than an 8.4 volt rechargeable early in the use cycle, but the rechargeable should overtake it as the alkaline's voltage declines. The 9.6 volt rechargeable sounds better than either, and stays that way until a recharge is needed. (My experiences are with Grado RA-1 and HPA-1).

 

[tangent]

Quote:

This is pretty much backwards

Yup.

Quote:

An NiMH battery has a much shallower decline.

More precisely, it drops quickly from its charged value to around 1.25V, where it stays with little drop over about 80% of the battery's life, and then it drops quickly from there at the end of its life.

See the attached images of battery discharge curves:

 

[tangent]

Oh, and I suppose I ought to answer the original question:

Quote:

Is there a difference between the no-name cheapies and the name-brand ones?

There shouldn't be a big difference. Are you sure you're not comparing alkalines to a zinc battery?

I'm a fan of rechargeables because they have a lower impedance than alkalines. Lower power supply impedance equals better sound, as a rule. That's why so many amplifiers talk up the size of their main rail capacitor bank: the more capacitors you have in parallel, the higher the capacitance and the lower their overall impedance.

Quote:

I'm too poor to afford rechargeables.

Hmmm, that's odd. I'm too poor to afford alkalines!

Cost of a 2-battery Plainview rotation set, plus charger: about $30
Cost of an alkaline 9V: $2
Break-even point: 15 alkalines.

It wouldn't take me all that long to go through 15 alkalines.

 

[Kirosia]

I'm not really sure if they're zinc or alkaline, they're "walgreens brand heavy duty power cell" batteries. Atm, I have very little money, I know rechargeables are the way to go, but at this point it's somewhat out of my reach.

 

[HiWire]

I feel kind of glad to have my NiMH battery then. My Sony rep stole them from some other device for my D-EJ2000 (NH-14WM or something - gumstick)

Slightly off topic, but I prefer using NiMH to Li-Ion (& Polymer) because of the greater life in cycles. I know that Lithium batts are lighter, and hold more power, but I generally tend to keep my batteries a long time, and cycle them conscientiously. The Lithium batteries just die with age, apparently.

I'm still using the original NiCad battery in my 10-year old Remington shaver. Scary, wot?

 

[milorca]

Quote:

Originally Posted by Kirosia I'm pretty low on cash right now, I might get rechargeables If I decide not to sell my RA1/RS1.

Look baby, if you can no afford "any thing" get out of this page, got it ?
You are trying to be everywhere and I am thinking that you are a waste, just to kill time it is no so ????
so, if you can not afford a couple a "cheapo' BATTERIES remain silent...and thanks
el otro

 

[PATB]

Quote:

Originally Posted by Jahn also, as you mentioned, the alkalines have a slooow slope of degradation in an amp, so i'm stuck for a few hours wondering if i should toss the still-usable batteries or continue to listen to semi-distorted hissy cloudy mushy sonics until the audio dies - and the SR-71's LED still going strong lol.

Well, the first set of alkalines (Duracells like what Ray shows on his website) on my SR-71 finally gave out just two minutes ago. I didn't hear any slow degradation in sound quality. All of a sudden, in the middle of a Macy Gray song (Time of My Life), I heared some hissing sound. I turned the SR-71 off to see if that would fix it. When I turned it back on, I got no sound at all. But like you said, the LED was still going strong! I replaced the batteries with a new set of Rayovacs and all is well again. I guess in the case of the SR-71, just replace the batteries when they go totally dead.

 

[Fishing]

Quote:

Originally Posted by milorca Look baby, if you can no afford "any thing" get out of this page, got it ? You are trying to be everywhere and I am thinking that you are a waste, just to kill time it is no so ???? so, if you can not afford a couple a "cheapo' BATTERIES remain silent...and thanks el otro

This is a joke right?

If it isn't, then you're an ass. Why would you take a shot at someone's financial situation? You don't have any right to tell someone on this board to remain silent.

PS. Your writing stinks (grammatically and content-wise).