MZ-NH900 - Safe to upgrade battery?

[Dice]

I have read this page: http://forums.minidisc.org/index.php?showtopic=7423

Where it is recommended to upgrade the battery to a 1400/1450mAh, but there are reports of higher capacity batteries swelling when charged in the NH900 - http://forums.minidisc.org/index.php?showtopic=12583&hl=

I have a NH900 ordered (expecting it soon) so i'm sorta planning ahead. I can buy this 1350mAh battery pretty cheap (says made in Japan) http://www.dse.com.au/isroot/dse/images/products/s3399.jpg

Specs:

# Digitor replacement battery to suit most minidisc players, Sony Walkmans and other branded personal players.

# 1.2Volt NiMH (Nickel Metal Hydride) 1350mAh

# Replaces original batteries: SanyoHF-A1U, Panasonic HHF-AZ01, HHF-1PSC, RP-BP140H, HHF125T, Sony NH-14WM and Sharp AD-N55BT

Any thoughts/info on replacement higher capacity batteries greatly apreciated, i don't want any bad batteries ruining my MD

[sebastianbf]

I use only 1400mah batteries with my mznh900. Not a single problem . Ever. In fact, I charge them with my player. If you're gong to buy batteries try to buy sony batt.

[Richard]

I use only 1400mah batteries with my mznh900. Not a single problem . Ever. In fact, I charge them with my player. If you're gong to buy batteries try to buy sony batt.

I'll second that - I have an extra NH14WM for my NH900 and another for the E900 and never had any issues. As Sebastian says I would be inclined to stick with Sony original batteries myself, but that's just me.

[The Low Volta]

I use a 1450mAh GP-powerbank gumstick in my NH900 and charge in the recorder... I have never encountered any difficulties/problems or strange behaviour

I guess the most important thing here is to remember that NiMH batteries can't handle overcharging! I only charge when I'm around to check whether it's done or not and can honestly say that my NH900 has never sat in it charging cradle for longer than 5 minutes after the charging icon disappeared

[greenmachine]

I guess the most important thing here is to remember that NiMH batteries can't handle overcharging! I only charge when I'm around to check whether it's done or not and can honestly say that my NH900 has never sat in it charging cradle for longer than 5 minutes after the charging icon disappeared

I don't think this would be necessary - as soon as the charging icon disappears, the charging process should have come to an end. Overcharging more likely could happen if you charge your battery, discharge it only partially, recharge, discharge partially and so on. I don't think the internal charger would be smart enough to detect the exact shut-off point. Any precise infos about the charging method anyone?

[rei-gouki]

greenmachine is prolly correct. Though I don't remember reading anywhere about Sony using trickle charging, it prolly doesn't hurt to poke around about it...

Regarding the topic NH14WM with MZNH900, I recently purchased a new MZNH900 and got a NH14WM as a spare. I've just put it through one charge with the provided NH10WM to check that it was working and get an idea of the charging period so it looks good for trying the NH14WM.

A point of note is that the MZNH900 appeared to have a bit of trouble charging it. I put it in the cradle to charge and it stopped rather quickly. A quick check showed 2 bars on the meter. I have (possibly stupidly) pressed the stop button for about 3-4 more times as it seems to have stopped after 20 minutes or so after each press. I don't know if this is that "initial charge problem" mentioned in the notes section of the packaging or if the charger just can't tell when it's full due to the extra capacity and possibly substantially different charging characteristics. Information on the NH14WM seem so revolve around it being one of the largest capacity gum batteries rather than anything more technical despite it being around for a while :/

I am currently using up the "first" charge of my NH14WM. I'll prolly be back to report if something really abnormal happens... but as of this moment, there is no bulging, even after whacking the charge button a few times.

[Toddz]

Dear All

Any idea how much better the performance is from one of these batteries compared to the standard one supplied with the mznh-900. in hours mins etc....

regards

toddz

[tommypeters]

Without testing them an educated guess would be that the difference in time is proportional to the difference in mAh (1350 compared to 900). That would mean 50% longer time for NH-14WM.

[Christopher]

No doubt. You'd have to be silly or I suppose desperate to justify using the stock battery considering the difference.

[Toddz]

Thank you for your reply i think i might invest in one of these from ebay this afternoon...

£7.00 including p&p doesnt sound to bad to me....

regards

toddz

[tommypeters]

BTW, Sony also has a 1750 mAh gumstick battery:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...Y_BIN_Stores_IT

[rei-gouki]

A quick update about the NH14WM. I had been getting weird times from it. I'd charge it for about 2.5hrs (a little short, based on calculations) and it's run flat FLAT with only a little warning. It'd show one bar or blink a little before cutting out and then not starting up at all. From my experience with the NH10WM (and previous MD recorders), there's meant to be a "Low Battery" screen and other such warnings so I thought this was just plain dodgy.

On inspection of the contact terminals, I found that the negative terminal at the bottom of the gumstick bay had 2 contact points in the NH900. Then comparing the NH10WM and NH14WM, I found that the shrink wrapping on the NH14WM covered a larger portion of the negative terminal (thought nothing of it before even though I noticed it was a little different). On closer inspection, it appeared that the contacts were in contact with the plastic wrapping and not the metal surface. A minute or 2 later, I had shaved off the extra wrapping around the negative terminal and reinserted the battery (this is just after it cutout and wouldn't start up again) and it displayed a "Low Battery" warning as the reason it's not starting up, where before there was nothing at all. Charging it now to see if that fixed anything else like the life the battery is meant to be providing as well as a proper low power warning.

I hope this helps the next guy so don't charge the MD as many times as I did before working it out...

[Toddz]

I have recently bought one of the sony nh14wm from ebay,and i was not overly impressed with any real extra battery life from it,may have a look at the termainal issue as well to see if there is a problem,it charges up in about 2.5 hours but battery life combined with a duracell mp3 aa didnt seem any different at all from the standard gumstick..

regards

toddz

[Human]

I don't think this would be necessary - as soon as the charging icon disappears, the charging process should have come to an end. Overcharging more likely could happen if you charge your battery, discharge it only partially, recharge, discharge partially and so on. I don't think the internal charger would be smart enough to detect the exact shut-off point. Any precise infos about the charging method anyone?

Hi greenmachine

Do You know this web site about batteries ::: http://www.batteryuniversity.com/

I visited this web site several days ago [i think the link to it was given by someone on this Forum].

I think this web site is very very interesting.

Cheeers, ....

P.S. To ALL USA Forum Friends - wishing You a Happy Thanks Giving Holiday.

Human :: from Vancouver, BC, Canada

Edited November 24, 2005 by Human

[greenmachine]

Thanks, i know about this site and would highly recommend it to anyone interested to get the best performance out of their batteries.

[Human]

Thanks, i know about this site and would highly recommend it to anyone interested to get the best performance out of their batteries.

Now when thinking about it ==> actually i think that it might be You who posted the link here to that site

[rei-gouki]

ok, the Low Batt indicator is still not showing for the NH14WM.

It still charges up in about 2.5hrs.

And it played LP2 for a little over 10hrs (10.5hrs is the rating for the NH10WM)

Has anyone else been getting this from their NH14WM? If not, I'm thinking I got a crap one.

[greenmachine]

Sounds like the (timed?) charger interrupts the process too soon and you don't get a full charge. The battery is propably ok. You can either manually force it to continue charging for pretty much exactly one more hour (but not more or you will overcharge it and the battery might irreversibly swell) or use a smarter external charger.

[Toddz]

i have also found that i did not get any more time wise out of the NH14WM battery than the standard one,mine charges up in about 2.5 hours not very impressed really any one else got any comments on this has anyone got a substantial increase in playing time from there nh14wm??

regards

toddz

[greenmachine]

The nh700 also shuts off after pretty much exactly 2 hours, no matter if you charge the default 700mAh or a 2000+mAh battery. You need to force it to continue charging manually by pressing the stop key or use an external charger to be able to use the full battery capacity.

[greenshank]

FYI FWIW my NH900 just managed to play HiLP with the supplied NH-10WM for 14.5 hours as against the official 10 hours. Mind you it was at a volume of 10/30 (which was plenty enough through my Sennheiser MX500s!) Does anyone know what volume Sony use to get their figures? Did I just get a very good battery? (Perhaps it's a mislabelled 14WM... yeah right.)

Edited November 29, 2005 by greenshank

[Toddz]

So are we saying that we need to charge for another hour after my mznh-900 swithches off charging taking it up to about 3.5 hours??? is that an automatic cut off of time no matter what battery you use... standard or nwh14..

thanks

toddz

[rei-gouki]

I can't get it to stay on for another hour. After the 2.5hrs stop, I can get it to charge for about another 20 minutes before it cuts out again.

In slightly other news, I "ran flat" this morning. I attached the external AA for about 1.5 hours, playing in a 27-30°C day (was going about town), then detached it after stopping the player. atm, it's been playing for the last 30 minutes and indicating 4 bars (should have been about 2 bars left this morning base on usage). I don't know if the NH900 uses shared power, though... need to consult the manual... but then charging the gum with a AA... what a waste regardless... :/

... so it's starting to look like the battery charge meter is running a random number generator too...

EDIT: congrats, greenshank. Exceeding such numbers are a rarity, these days.

Edited November 30, 2005 by rei-gouki

[greenshank]

In slightly other news, I "ran flat" this morning. I attached the external AA for about 1.5 hours, playing in a 27-30°C day (was going about town), then detached it after stopping the player. atm, it's been playing for the last 30 minutes and indicating 4 bars (should have been about 2 bars left this morning base on usage). I don't know if the NH900 uses shared power, though... need to consult the manual... but then charging the gum with a AA... what a waste regardless... :/

It does use shared power, I believe. And I hope it only charges if you tell it to. As you say, waste of an AA otherwise.

EDIT: congrats, greenshank. Exceeding such numbers are a rarity, these days.

Thanks, lucky me!

BTW I don't get the way the bars work. It seems to take almost no time to leave the "maximum power" level. Later it plays for ages (3 or 4 hours?) at the "OMG I'm practically out of juice" level. It seems highly non-linear so I've stopped taking much notice of it.

[Toddz]

it definetley uses shared power i have tested my duracell mp3 aa battery when low power comes on,buy removing aa battery and using the battery self tester.. just to make sure iam not wasting the aa battery..

regards

Toddz

[rei-gouki]

It does use shared power, I believe. And I hope it only charges if you tell it to. As you say, waste of an AA otherwise.

Yea. I had a look at the manual... it doesn't explicitly say that it's shared, but the recommendation to attach the AA when the gum is on full charge for maximum play time suggests that that's the case. It has no way of disabling it... which is probably what the "battery off" thing on the N10 is for... Anyway, I'll be removing the gum when I attach the AA pack since I use it for backup.

BTW I don't get the way the bars work. It seems to take almost no time to leave the "maximum power" level. Later it plays for ages (3 or 4 hours?) at the "OMG I'm practically out of juice" level. It seems highly non-linear so I've stopped taking much notice of it.

Yes, again. I get that with my N707 with the default NiCd AA (and this was using one from the days of R70 too), not sure about regular dry cells - never used them regularly enough to leave an impression. I haven't had much play time on my NH900 with the NH10WM default battery in there, but it was doing something like that according to what I remember. As for the NH14WM... It seems to show 4 bar for the first half, half when you got 1/4 left, 1 when "you are almost out", and blinks for no more than 30 minutes play time. This was an observation made when just running LP2.

It's one of the reasons I didn't get the NH1 as it has no external on top of the fact that it could go for a while with the battery indicator blinking as you described. I have a habit of running rechargables flat before charging so I fully expect it to be a problem with me. Getting a spare Li-Ion to carry... is sorta out of my budget, too.