NH-14WM

[suestuff]

I am looking to buy an NH-14WM battery and I am coming across some that are labelled NH-14WM(A), some are NH-14WM(BC) and some have no additional letters. Does anyone know what the differences are in these batteries?

Sue

[Christopher]

I spent some time searching, and could not find any differences in mAh. I'm not sure what to say, perhaps just variations in model for region..

[Azureal]

I looked too and did not even see any of the mentioned variations in nomenclature the OP mentions.

Sometimes, non-OEM manufacturers will add additional characters to their model numbers to differentiate their generic product from the original manufacturer's product.

I have bought a few different models of "knock-off" Sony WM batteries and very few of them have lasted as long or held as good a charge as the originals did. There are however a several manufacturers who create and sell replacements for the originals, they do not try to copy the exact look, colors, writing of the battery packaging etc. Many on the board have had good experiences with these. My next batch will likely be one of these "replacement" brands rather than the cheap copies.

Do a search, I saw a thread in the past month with this very topic.

[Stuge]

no clue to me as well .

just make sure you buy original sony battery, and no 3rd party one .

also ,becareful with ebay (if case you buy one from there )

[sfbp]

I personally think the "real" Sony batteries are overpriced and that even the "fakes" most likely came from the same factory. Whether these are "seconds" remains to be debated.....

Also I have found that how well you can charge a particular battery depends more on what is being used to charge it. In some cases there are (service manual) adjustments that make a huge difference to how this goes. So far my most dramatic improvement was with MZ-NF810. Some "external" chargers may do better than the MD unit, eg the GP charger. Before that I bought a charger which was itself a patently obvious fake and never did anything.

Vapex and GP are both fine. Depends a lot on your unit. If you have an MZ-R91 you're laughing as these seem to really give an oomph to battery when charging. May be a coincidence but these and the MZ-NH3D (uses Li Ion LIP-4WM) are both made in Japan.

Stephen

[jim.hoggarth]

Hi all. My first post, so please be gentle.

It's my belief that the various changes in NH-14WM labelling were just to do with capacity: 1400mAh, 1350mAh etc.

As for fakes, well I did buy some from a guy in the UK which were obvious fakes, and undoubtedly from a batch imported from Hong Kong or the likes. Not just the round cap on the positive terminal, rather than a round-cornered square or rectangle, or the obviously sub-standard plastic wrapper, but also the fact that they were at least 1.5mm too long and would not physically fit into the battery compartment of an R55, N710, R91 etc!

My experience with 'probable' fakes is that they self-discharge very quickly, and have a much shorter life than the 'real deal'.

Incidentally, Stephen, your comments on the MZ-NF810 are interesting. I recently put together an N710 package I sold (as you know, the N710 and NF810 are basically the same machine). As the customer was a regular, I decided to do him a special package and supply the NH-14WM battery instead of the NH-9WM which originally shipped with the N710. I had just given the battery a full test, and it came out at well over 1400mAh capacity. To my astonishment, the battery would not work in the N710. When attempting to charge from the mains adapter alone, the display would not even show the 'charging' symbol. When placed in the charging cradle, the machine just gave a slight noise, waited two seconds, gave the same noise, and repeated this process until power was removed (as an aside, the noise is of the overwrite head load motor resetting, which always happens at 'power on' to ensure the lid is not in the locked position).

Naturally I assumed this was a fault on the recorder, so I tried another. Same problem. And the same was seen with another four N710 machines. And yet, an NH-9WM that I had also just tested recently, again to its full capacity (900mAh), worked perfectly in every one of these machines. Since coming across this phenomenon I have not had time to investigate further, but there's obviously something not quite right here! I would be interested to hear of your experiences with charging these gumsticks, and any adjustments made to improve performance. Such as why the N710 is so finicky?

Jim

[sfbp]

I found that going through the adjustment routine worked wonders. Almost all the parameters needed adjusting upwards by 10% or so. I think this affects charging. I know I had a 910 that would only work with certain chargers, yet another that worked with all chargers. Nothing to do with the battery. My conclusion (no longer have that one) that adjustment is probably the answer. I can think of no reason why it would work with a 10WM (btw mine are 10WM's not 9WM's) and fail with a 14WM. In fact my experience has been to the contrary.

By the way folks, I would like to take this opportunity to welcome Jim to our community. He is in the business of fixing MD units, runs a very reputable service out of England, and would no doubt be glad to hear from y'all with both stories and requests for his servicing skills.

[jim.hoggarth]

Yes, Stephen, you are right. NH10WM, but of course they are 900/950mAh capacity - go figure. I have found my self getting quite confused today, so I'll blame it on tiredness and too much sugar. But the N710's genuinely choked on this battery, which otherwise performed flawlessly in an R55, an E510 etc. I must try this again soon, to see if the problem can be reproduced.

And thanks for the free publicity. The bottle of whisky is in the post!

Jim

[suestuff]

I am unclear what you mean by service manual adjustments. The model that I have is the MZ-M100. Are there any adjustments that can be made to improve battery charging.

Also, here's another question about this model. I do not recall getting an AC adapter when I bought this, although I am sure that I did, and perhaps it's even in the house somewhere. Anyway, the manual says do not use any adapter except the one provided. The package and the manual, as best I can tell, don't tell you anything about the adapter and have no real pictures of it. If I do have it, how can i tell which one it is. And if I don't have it, can I use other Sony MD adapters that I have?

Any help would be appreciated,

Sue

[sfbp]

I am unclear what you mean by service manual adjustments. The model that I have is the MZ-M100. Are there any adjustments that can be made to improve battery charging.

Absolutely. But you need the gear and some patience.

Also, here's another question about this model. I do not recall getting an AC adapter when I bought this, although I am sure that I did, and perhaps it's even in the house somewhere. Anyway, the manual says do not use any adapter except the one provided. The package and the manual, as best I can tell, don't tell you anything about the adapter and have no real pictures of it. If I do have it, how can i tell which one it is. And if I don't have it, can I use other Sony MD adapters that I have?

Shouldn't be a problem to use different adapters at all. It needs 3V like all the other models that use NiMH battery (the main exceptions are RH1/M200, N10, DH10P, and NH1, I think, though there are some other rare ones like NH3D and EH1 - all of these are Li Ion and require a higher voltage).

Even the old Electrohome multi-voltage multi-tip (if you are in the USA or Canada) work fine. But all the 3V Sony ones are interchangeable.

[jim.hoggarth]

I have had time to investigate the problem I had with the N710s further. I was testing these using my bench PSU, set to 3.00 volts. When I came across the problem again, I upped the PSU output to 3.05 volts and all problems disappeared. And that was over several examples of N710, so it looks like a generic voltage adjustment problem on that model.

Jim

[sfbp]

I have had time to investigate the problem I had with the N710s further. I was testing these using my bench PSU, set to 3.00 volts. When I came across the problem again, I upped the PSU output to 3.05 volts and all problems disappeared. And that was over several examples of N710, so it looks like a generic voltage adjustment problem on that model.

Jim

Agree 100%. My 810 (710 + radio-on-a-wire) charges batteries perfectly ever since I did the adjust; before it used to cut out much too early, and I was stuck with charging the gumstick in a wall charger instead. Of course this model has a charge stand, and it seems like the paradigm (sorry for the fancy word, M.O. would be better I suppose) is that such units charge whenever they are rested in the stand, meaning that often their batteries don't "run out" much. Generally batteries work better if they actually discharge most of the way, though with Lithium you never want to go "all the way".

I have also noticed that my MZ-R91 (and one I bought my dad in England) is capable of reviving NH14WM's. That model was made in Japan. The NH3D's are reported to be particularly good at charging LIP-4WM, and this model was also made in Japan.

Almost as if whatever gear they had at the factory wasn't quite calibrated correctly. Mains voltage is 230V 50Hz there, the same as Europe and Australia. Japan is about 10% or more less than here in North America, 100V 50Hz or 60Hz instead of 110 60Hz. Perhaps the test circuitry was developed in Japan and didn't **quite** do the job in Malaysia. Some systemic correction or drift, in other words. I found the adjustments were quite consistent, too - almost all the relevant settings needed things increasing by about 10% to meet spec. Coincidence?

Stephen

[stahlhelm]

Hi all,

I've bought a "Pisen" gumstick for my MZ-NF810 because the Sony gumstick didn't hold the charge longer than a single day even if I didn't use it. The unit's charger won't charge the Pisen because of I don't know...

So I went for a GP gumstick charger (couldn't find a Pisen charger) but it is almost the same. It won't last longer than three days maybe half an hour use each day. What is going on? Where can I get a working battery?

Thank you

[sfbp]

You need (in my opinion) to readjust the charging circuits and voltage adjustments generally in your NF810. That and only that will fix the problem, I think.

Or buy an MZ-R91 purely to charge batteries. Worked for me.

[jim.hoggarth]

Hi all,

I've bought a "Pisen" gumstick for my MZ-NF810 because the Sony gumstick didn't hold the charge longer than a single day even if I didn't use it. The unit's charger won't charge the Pisen because of I don't know...

So I went for a GP gumstick charger (couldn't find a Pisen charger) but it is almost the same. It won't last longer than three days maybe half an hour use each day. What is going on? Where can I get a working battery?

Thank you

Hi there. Does your GP charger state the charging current? And does it have an LED which indicates still charging / charged up? If so, time how long the charge cycle lasts and post the info and we can tell you if the battery is being charged up to its full capacity. If not, it could be a duff battery or a duff charger. Another possibility is that the Pisen battery has not been fully conditioned before leaving the factory.

How many times have you attempted to charge and discharge the battery? New batteries, or batteries which have not been used for some time, will only take a partial charge the first time, sometimes as low as 20%, and each on successive charge/discharge cycle the capacity gets better. In my experience it can take up to five full charge/discharge cycles before full performance can be obtained.

Jim

[sfbp]

I see what you mean, Jim. Yes, getting something that really charges the battery with an "oomph" at least once makes a huge difference. What often seems to happen is that on one of these charge cycles, the battery gets really hot. After that it may work a lot better. I heard tell that this corresponds to some breaking down of crystals within the battery - crystals that prevent it from proper functioning.

Stephen

[jim.hoggarth]

I see what you mean, Jim. Yes, getting something that really charges the battery with an "oomph" at least once makes a huge difference. What often seems to happen is that on one of these charge cycles, the battery gets really hot. After that it may work a lot better. I heard tell that this corresponds to some breaking down of crystals within the battery - crystals that prevent it from proper functioning.

Stephen

The battery can get hot some times, although this not a good sign as heat is one of the wost enemies of a rechargeable battery. Crystals mainly form due to shallow discharge cycles, with nickel cadmium batteries being the worst affected. This brings about the so-called 'memory effect', and is the reason why we were always told to fully discharge NiCd batteries before recharging. Of course NiMH does not suffer the same way, but over time the same crystal build up will occur.

The best way to condition a battery is to do a deep discharge, followed by a slow recharge, and again for several cycles. This reduces the crystal size and breathes new life into the battery, unless the cells are so far gone nothing will bring them back. But, some battery powered equipment will not perform a deep discharge as there is a trade-off between battery capacity and life. That's why your mobile (cell phone) may only last a few days before cutting off, even though in truth there is still some 'juice' left in the battery. Deep discharges ultimately reduce the cycle life, so a typical rechargeable with a 100% depth of discharge may only give 500 cycles before being chemically spent. But, perversely, the best way of revitalising a 'constipated' battery is to perform a few deep cycles.

I have taken a seemingly useless battery, which only gave a five minute charge initially, and after a few slow-and-deep cycles got it back to at least 85% of 'as new' capacity. But, the important point is the depth of discharge. I have found the best way is a 10 ohm medium power resistor shorting out the two terminals. This gives a reasonably slow discharge current of around 120mA, and by virtue of being a constant low resistance will utterly flatten the battery. When followed by a relatively slow charge (I use a Sony E510 as my charger, attached to a PSU with a current read out), after around six cycles the battery is either back up and running or obviously will never make the grade. I perform this with every battery that comes into the workshop, and I doubt more than 5% have to be discarded.

However, I have no idea how long this revitalisation actually works. But I have yet to have any customer complain that their battery only lasted a week or so, which makes me believe I am doing something right. Incidentally, watching the current being drawn by the machine performing a charge is quite education. It is easy to assume it simply pumps a constant charge into the battery. But no, the current varies considerably, at least initially, as the electronics takes measurements and 'tastes' the battery, as it were. Only after some time does the battery get the full 500mA 'poke' that most minidisc chargers can provide.

Jim

[stahlhelm]

You need (in my opinion) to readjust the charging circuits and voltage adjustments generally in your NF810. That and only that will fix the problem, I think.

Or buy an MZ-R91 purely to charge batteries. Worked for me.

Ok, how can I readjust my NF810? I suppose I need to download the service manual and then...?

Hi there. Does your GP charger state the charging current? And does it have an LED which indicates still charging / charged up? If so, time how long the charge cycle lasts and post the info and we can tell you if the battery is being charged up to its full capacity. If not, it could be a duff battery or a duff charger. Another possibility is that the Pisen battery has not been fully conditioned before leaving the factory.

How many times have you attempted to charge and discharge the battery? New batteries, or batteries which have not been used for some time, will only take a partial charge the first time, sometimes as low as 20%, and each on successive charge/discharge cycle the capacity gets better. In my experience it can take up to five full charge/discharge cycles before full performance can be obtained.

Jim

Hi Jim,

the GP charger is a simple one: does not have a display showing the current but has a LED which goes from red to green when the battery is fully charged. I tried only once the Pisen battery but IMO it should perform better for the first shouldn't it?! I'll trly a few more cycles and come back.

Another thing came into my mind: maybe if I leave the battery inside the unit it constantly pulls a very tiny current from the battery? Just a thought...

Thank you

[sfbp]

I (mainly) went through the adjustments for all the voltages (except the USB stuff which they refer to as VSB, I think). It's very fiddly finding all the test points on some units, you need a degree in Sony-ology to do it straight off, as one has to find the contacts on the other side of the board from what is shown, assuming you don't want to actually remove said board which is a whole nightmare in itself (requiring desoldering and resoldering between 5 and 10 contacts).

I think I ended up increasing a lot of the voltages to meet spec. My assumption is that there is a cutoff voltage at which the electronics thinks the battery is fully charged. If this is set too low, the battery will never get fully "topped up". Once I did these adjustments, the unit seems to charge for quite a bit longer. And on the MZ-RH910, same thing.

Jim, I should emphasise that the "getting hot" only ever happened once per battery, and that afterwards, it always charged nicely. This was long before I knew how to adjust the units, and it was from charging in the R91 in each case, which unit (to my belief and knowledge) is usually absolutely correctly set. Possibly because it was made in Japan, and there are some differences between the test gear and/or manufacturing processes (in Malaysia, where the voltage is 230 instead of 100) as opposed to the NF810 and many other models which do NOT seem to have been sold with the words :made in Japan: written on them.

[stahlhelm]

I (mainly) went through the adjustments for all the voltages (except the USB stuff which they refer to as VSB, I think). It's very fiddly finding all the test points on some units, you need a degree in Sony-ology to do it straight off, as one has to find the contacts on the other side of the board from what is shown, assuming you don't want to actually remove said board which is a whole nightmare in itself (requiring desoldering and resoldering between 5 and 10 contacts).

I think I ended up increasing a lot of the voltages to meet spec. My assumption is that there is a cutoff voltage at which the electronics thinks the battery is fully charged. If this is set too low, the battery will never get fully "topped up". Once I did these adjustments, the unit seems to charge for quite a bit longer. And on the MZ-RH910, same thing.

Jim, I should emphasise that the "getting hot" only ever happened once per battery, and that afterwards, it always charged nicely. This was long before I knew how to adjust the units, and it was from charging in the R91 in each case, which unit (to my belief and knowledge) is usually absolutely correctly set. Possibly because it was made in Japan, and there are some differences between the test gear and/or manufacturing processes (in Malaysia, where the voltage is 230 instead of 100) as opposed to the NF810 and many other models which do NOT seem to have been sold with the words :made in Japan: written on them.

Hi,

where and how can I do those adjustments on my NF810? What sould be the values?

Thank you

[sfbp]

Hi,

where and how can I do those adjustments on my NF810? What sould be the values?

Thank you

Do you have a voltmeter and/or regulated power supply with current metering?

If so, then it's all in the Service Manual, pages 18-22. A word of warning - do NOT NVReset (the very first step) because you will lose all the (laser and other) settings that can only be got from having a test disk. In addition, there are certain settings connected with encryption that have to be changed (the "patch data") and you must steer well clear of this.

(

if you do the unthinkable because you like to ignore the instructions above, the following discussion may help... but it will NOT fix the NetMD stuff, and your USB connection will likely be useless.

http://www.minidisc.org/sony_mzr_reset.html

)

Your objective is to stop at page 22 of the S.M.

If you're an electronics whiz, you'll have no trouble with any of this. I fudged my way through it - but if you take one false step there's no way to recover, as many people have observed.

[jim.hoggarth]

Hi,

where and how can I do those adjustments on my NF810? What sould be the values?

Thank you

Hi again. If, as you have already stated, you only tried charging the Pisen battery in the GP charger once, you must persevere and try several times, discharging the battery each time, until you can safely say there is something wrong. I have known some Sony models reject batteries that have not been conditioned, but happily accept them once they are in a healthy state (this may or may not be connected to Stephen's findings on voltage, I don't know as I haven;t yet experimented with these).

Please persist with the external charger first. And you *must* make sure that the battery contacts on the NF810 are in good condition with no corrosion at all. Normally the contacts deep inside do not need checking, as leakage only comes from the positive end which is where the battery flap contact is. However, if you have had a bad battery leak at some time, liquid can run down the battery and collect inside at the other end. But this is very rare. I have only seen it a couple of times.

Personally, I wouldn't start messing with the adjustments unless you are already experienced at electronics, with the more experience the better. If you are a total novice and have never stripped or serviced an item of electronic equipment of this complexity before, you may totally wreck the recorder.

Jim

[sfbp]

Agree 200%, Jim. But he did ask.......

[stahlhelm]

Ok guys,

I take you words. Myself I wouldn't mess with the unit either unless there is no way out.

I'll try a few more cycles with the Pisen battery and I'll see what is the next step.

The contacts on the unit's battery door seem ok I can't see what is on the bottom. But the Sony battery looks clean so I wouldn't worry about dirty contacts.

Thank you for you help will come back with some resutls

[jim.hoggarth]

One more thought - when you place the NF810 into the cradle (with the battery inside, of course), wait for at least 30 seconds before thinking the battery will not charge. I have been doing some experimenting today, with an N710 showing charging problems (same basic electronics as the NF810), and when a totally flat battery was first tried the recorder made that odd little motor noise it does sometimes when you place it in the cradle, then sat there drawing a heavy current load for several seconds (about 650mA). Then the current dropped, it gave the same motor noise, and then pushed 650mA through the battery again. And, several seconds later, the current dropped to zero and *then* the battery started charging as normal.

And for you, Stephen: I can confirm your findings. This machine was not charging three out of six batteries. I did the voltage adjustment routine and found every setting was low. Only by a few or 10's of millivolts, say a 1.25v reading was 1.22v, but after adjustment to the absolute values given in the SM every battery worked fine (after the odd high-current cycles described above). Am I right in thinking you actually set these values higher, both on VCHG hi and lo and VREC hi and lo?

Jim

[sfbp]

Higher than what they were, yes. Blindly what the voltage readout said to spec. Not higher (than that!).

Since EVERYTHING seemed to be low, I actually suspected a voltmeter fault for the first couple of units (and now think there's some sort of systemic error with Malaysian made units). However have had no ill effects, touch wood.

So I cautiously implied that I might have put things a bit over, to allow for my old (duff?) voltmeter.

I don't have any absolute calibration, but the voltmeter doesn't quite agree with the RPS either. Mind you, for the 810 (and other 3V chargers) I didn't use the RPS - it only becomes important for the HiMD units, I suspect.

PS. I never thought of using the RPS as a way of monitoring charging on a routine basis. But it's a good idea.

[jim.hoggarth]

Higher than what they were, yes. Blindly what the voltage readout said to spec. Not higher (than that!).

Since EVERYTHING seemed to be low, I actually suspected a voltmeter fault for the first couple of units (and now think there's some sort of systemic error with Malaysian made units). However have had no ill effects, touch wood.

So I cautiously implied that I might have put things a bit over, to allow for my old (duff?) voltmeter.

I don't have any absolute calibration, but the voltmeter doesn't quite agree with the RPS either. Mind you, for the 810 (and other 3V chargers) I didn't use the RPS - it only becomes important for the HiMD units, I suspect.

PS. I never thought of using the RPS as a way of monitoring charging on a routine basis. But it's a good idea.

I must admit, I checked the DVM against the voltage readout on the PSU, after it became apparent the first few readings were all low, even though I was forewarned by your comments. Both exactly to 3.00 volts. Now that was a surprise! My next experiment will be with OWH voltages, to see if the power to the write head is low on some of the units I have already diagnosed as having a faulty optical assy, or those which just don't see to want to be fixed (specifically, giving a 138NG error on MO discs, as if the OWH is open circuit, which of course it isn't).

Jim

[sfbp]

My next experiment will be with OWH voltages, to see if the power to the write head is low on some of the units I have already diagnosed as having a faulty optical assy, or those which just don't see to want to be fixed (specifically, giving a 138NG error on MO discs, as if the OWH is open circuit, which of course it isn't).

Maybe I can "calibrate" said voltage against measured laser power....

[netmduser]

Today I received some Vapex 1450 to replace a dying NH-14WM (A) that does not hold the charge well. I decided to go with the Vapex after reading recommendations on here.

When I replaced it with the Vapex charging would not start. I was able to get the charging going only after connecting the single AA battery extendor with a fully charged AA and playing an MD for a few minutes. This I think gives an initial charge to the gumstick battery. After removing the extendor the unit started to charge.

I got this to work on an MZ-N1 in cradle. The next unit I am going to try with is NF810.

I suggest you also try this method if you have the battery extendor or wire the terminals to a standard charger for a few minutes my understanding is the MD unit is checking Voltage and other things before it starts charging for safety reasons.

If my method fails I may need to make the same voltage adjustments for the NF810. I so far have no idea how to do this for this model.

[sfbp]

You may well find that it's not either battery's fault, if you read Jim's and my posts higher up this thread, as we have discussed this issue in some depth.

Stephen

[netmduser]

You may well find that it's not either battery's fault, if you read Jim's and my posts higher up this thread, as we have discussed this issue in some depth.

Stephen

Yes I understand tweak V all you want I was just suggesting an alternative method, this method even works for older batteries that initially I found would not start charging. In the end I just decided to get replacement gumsticks. Gumsticks do not seem to have a long life.

[sfbp]

I've actually revived a number of gumsticks that were DOA, using my R91 which was never "out" to begin with. I think the majority of the units you are using are probably in need of adjustment.

Stephen

[netmduser]

I've actually revived a number of gumsticks that were DOA, using my R91 which was never "out" to begin with. I think the majority of the units you are using are probably in need of adjustment.

Stephen

Perhaps so, I just don't understand how they could get out of whack in the first place. Do you know in general if MDs charge by timer or by cutoff voltage? The vapex std charge is 15hrs 145mA.

[sfbp]

I've already advanced a theory - most of the NiMH gumstick units after the R91 were made in Malaysia, and I think there may have been across-the-board low settings somehow. No proof whatever, but my observations are pretty consistent, and confirmed by Jim.

Charging cutoff is definitely controlled by voltage.

[netmduser]

I've already advanced a theory - most of the NiMH gumstick units after the R91 were made in Malaysia, and I think there may have been across-the-board low settings somehow. No proof whatever, but my observations are pretty consistent, and confirmed by Jim.

Charging cutoff is definitely controlled by voltage.

For these 1450 or 1350 gumsticks it is expected to be fully charged after 14 hours?

[sfbp]

The specs from Sony say charge time is 3.5-4 hours, generally.

[Happy Hopping]

Today I received some Vapex 1450 to replace a dying NH-14WM (A) that does not hold the charge well. I decided to go with the Vapex after reading recommendations on here.

When I replaced it with the Vapex charging would not start.

I had the same problem, and I post it here. But for whatever reason, some1 deleted that thread as I can't find it, and there is surprisingly no search button in this forum.

The person who helped me out on this told me simply to use a knife to cut out the top part of the plastic wrapping, as the sony charger try to protect its own brand name battery by detecting the battery is a genuine sony or not. So once I cut out the plastic wrapping, the charger can charge my battery for 3.5 hr. or so, and I have no problem since

I wish I can find that thread, but without a search button there is nothing I can do

[jim.hoggarth]

When I replaced it with the Vapex charging would not start. I was able to get the charging going only after connecting the single AA battery extendor with a fully charged AA and playing an MD for a few minutes. This I think gives an initial charge to the gumstick battery. After removing the extendor the unit started to charge.

That is an interesting idea, although I feel the playing on battery only gave time for the charging circuitry to do its magic and you are reporting a coincidental happening. I will, however, investigate the possibility when I next have a candidate battery and machine, prior to adjusting the voltage settings.

Gumsticks do not seem to have a long life.

I do worry that the problems with charging we are reporting are leading to a hefty number of perfectly good batteries going in the trash.

I've actually revived a number of gumsticks that were DOA, using my R91 which was never "out" to begin with. I think the majority of the units you are using are probably in need of adjustment.

Anecdotally, prior to the voltage adjustment revelation, I have to agree that the R90/R91 was a superb battery charger. Although regarding this machine as a watershed may not be a total truth, as I have found the R55 model to be extremely finicky about batteries. As yet I have not had a chance to experiment with the really early (ie all metal) machines.

Perhaps so, I just don't understand how they could get out of whack in the first place. Do you know in general if MDs charge by timer or by cutoff voltage? The vapex std charge is 15hrs 145mA.

The charging circuitry relies on a quite sophisticated and dedicated chip. There's no timing involved, nor temperature sensing. It is done purely by dV/dt, ie changes in voltage across the battery terminals. When NiCD and NiMH batteries are fully charged, the voltage developed across the battery drops ever so slightly, literally by millivolts in the case of NiMH. It is this that turns off charging. This part works fine. It's getting the buggers to start charging that's the problem!

The person who helped me out on this told me simply to use a knife to cut out the top part of the plastic wrapping, as the sony charger try to protect its own brand name battery by detecting the battery is a genuine sony or not. So once I cut out the plastic wrapping, the charger can charge my battery for 3.5 hr. or so, and I have no problem since

I actually find that difficult to believe. I have seen many hundreds of these batteries, and never one that has so much plastic wrap stacked up on the top that the battery terminal will fail to make contact. You are writing about the positive terminal, are you? The one with the metal cap, not the flat end that forms part of the battery body? Perhaps the actual problem is that the battery contact is bent flat, or even backward on itself and pushed into the supporting plate, a condition I have seen several times. I would be grateful if you could confirm this by looking again at the battery contact, or even sending me a PM with a close-up photograph.

Jim

[jim.hoggarth]

One thing I forgot to add. I have now looked at several machines from the N510/N710 family, and they all appear to suffer the same low voltage problem, and by the same degree of scale. This not only adds credence to Stephen's theory about the Malay factories, but also allows us to generalise. It should be possible to describe the adjustments required without reference to a voltmeter, certainly for the models on which we have concentrated.

I have found, so far, that all the voltages are low. Only the two charge current settings are dead accurate, although they will probably wander if the charging voltages are changed. This is a good things as most folk who would have had access to a Digital Voltmeter undoubtedly would not have had the two 0.5% tolerance resistors required! The current settings are not critical anyway, I feel. Any slight changes should only marginally change the required charging time.

Upon advisement from the Guru Stephen, I may make available a list of Service Mode procedures to up the voltages on the N510/N520/NF610/N710/NF810 models. This would also benefit us, assuming we get useful feedback on the validity of this problem and the fix.

Jim

[sfbp]

I've decided I don't like the automatic title granted me by the post-counting part of the board's software.

Please, no more references to "Guru" - it's a bit embarrassing.