Decreased battery life on Sony MDs

[ardvaark]

I have Sony MZ710, MZS1 and MZG755 (terminally faulty). I began to notice that the AA NiMh batteries were becoming flat far quicker than I remembered several years ago when they were new. Either the batteries were losing their capacity or the MDs were increasing their consumption. Imagining the batteries to be the more likely cause I bought a power meter used for monitoring electric model cars/plane batteries (it contains 3 microprocessors and calculates current x time to display a milliamp-hour figure). This confirmed that the batteries old and new had similar capacities which were in the region of the rated value.

The alternative explanation is that the consumption of the minidisc recorders is increasing. Has anyone noticed something similar? Are the motors brushless or brush type? If they are brush type then is there an accumulation of carbon dust? Is there some kind of regular service required to maintain low current consumption?

[THIS SUCKS]

dude its the batteries. screw the meter! all of my md units are very old and heavily used. i have never noticed an increase in power usage. just buy new batteries at least 2000mA hrs for aa's and you will see...

[HeshNeedsCandy]

This is so much thinking about so little data to make any claim of this one way or the other....

Every cycle of a Charge / Discharge will have less time with usable voltage output than the cycle before it.

You are focused only on capacity or mAh and aren't even mentioning probably the most important part is that the cell maintains >1.2 volts.  Most rechargeable cells are barely over 1.3v after a full charge.

The batteries might have nothing wrong with them either, maybe you are moving around too much and the player is forced to re-read more often.

Maybe you're skipping around different tracks too often, causing the player to overuse its motors to fast forward, seek, rewind.

Maybe it's a hotter ambient temperature which will decrease overall efficiency of the cells. 

There's just so many variables and you have only used what, 4 different cells of varying ages and mileage put on them?  These cells are mass produced too... like you'd have to calculate a margin for error based on the variance of the cells performance straight out of their manufacturing.......

Chalk it up to the cells are bad, get some nice quality high mAh cells and move on! 

Cheers.

[sfbp]

Most sites have automatic closure of old threads. Please don't abuse our hospitality by resurrecting an old thread in this way.

The battery issues are mostly well-understood, and in nearly all cases it's due to one of:

1. Contact resistance increasing (gunk buildup or some springy part not pushing so hard)
2. Improper adjustment of the charging circuitry that decays over time
3. Abuse of the battery by keeping it at full charge instead of letting it run down once in a while. I myself am particularly guilty of this.

Unfortunately, your remarks about "throwing it away" (my apologies for misquoting you) may well be true about Li-Ion. The vast majority of MD gear doesn't run on Lithium. This is good, because they are rare and expensive for these units. On the other hand there are well-documented examples of NiMH "waking up" (provided they don't actually burst) and behaving as model citizens for 8 out of their 9 lives, like a cat.

'Nuff said. Please start your own topics if you must lecture us. We can then choose.