Panasonic mobile phone driving me nuts!

I bought a Panasonic G520 Mobile Phone a few years ago. When I charge the phone, the battery shows a full charge and stays turned on in standby for hours - but when I try to dial a number the phone switches off as if the battery is flat, even though the charge is showing full bars. If I then plug the charger in, turn the phone back on and then dial, it dials out fine.

I was thinking of purchasing a new battery but I'm not sure now... We've hardly used the thing and wouldn't have made an hour of calls on it all up - but I don't want to throw good money after bad either.

Anyone have any ideas how to find out if the fault is with the battery or with the phone itself?

Allan.

Reply to
Just Allan
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Sounds excatly like the fault I had with my rather old Nokia. Turned out to be tarnished contacts on the SIM, and then the keyboard. As soon as I pressed anything, the phone would go off. So I gingerly dismantled the phone and cleaned all the contacts with a pencil shaped eraser. Works OK now.

Reply to
fred

Freeze the battery in a plastic bag overnight , often this will dump all charge memory and restore the battery for some use and if it doesnt help nothing lost .

Reply to
atec

Could be the phone uses a Lithium Ion battery which has a limited life which is linked to age not use.

If it isn't the battery, a whole host of possible faults may be contributing to the fault.

Does the phone operate normally when the charger is connected to it? If so, the battery is most likely the culprit.

Cheers, Alan

Reply to
Alan Rutlidge

That is a very common fault with Lithium Ion batteries in mobile phones. The battery develops high internal resistance and appears to be charged until the phone starts transmitting. Dirty contacts are the next most common IME.

Lithium Ion batteries have quite a short life expectancy even if they are not used very much. It is more dependent on the temperature it is kept at. For example, here in Cairns I would not expect to get more than 3 years out of a phone battery.

The easiest way is to try another battery.

-Mike

Reply to
Mike Warren

Someone suggested this to me a couple of days ago. Cleaned gold contacts but still no go...

Reply to
Just Allan

Thanks - I'll try this, since as you say - nothing to loose now...

Reply to
Just Allan

It's a Ni-MH battery...

Reply to
Just Allan

Yep... Thanks to all who replied, to... I might try connecting a power supply to the phone's battery contacts tomorrow. If the phone is at fault (and when I use the charger and the phone works, it somehow bypasses the fault), then connecting a power supply directly to the battery contacts on the phone (as if it were a battery) it should produce the same fault as the battery did... But if the fault disappears, then it's definitely the battery, yes? Anything wrong with my logic here??

Allan.

Reply to
Just Allan

With the logic? No .. Just keep in mind the battery voltage will be lower than charger voltage..

I think if it doesnt cause the fault while plugged into the charger, that implies enough that the battery is at fault. While on charge, its operating from the power adapter, not the battery.. Thus, if this is eliminating the problem, that to me suggests it is indeed the battery at fault.

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Reply to
Lord-Data

That's what I originally thought myself - until two different phone shop owners told me the same thing - which caused me to doubt my own diagnosis... They said if the phone turns off while the battery shows full charge bars, it was likely that the fault was with the phone, not the battery, since it can stay on in standby for hours.

Thanks for the confirmation though... What I'll do today is, dig out a variable power supply and power the phone via the gold contacts as if it were a battery, just to be sure there's not some damaged circuitry that separates the charge socket from the battery contacts.

Thanks again to all who replied...

Allan.

Reply to
Just Allan

It might be an interesting exercise, (when using the power supply) to monitor the current the phone is drawing while in standby and "talk" mode too.

While I tend to think that the battery is the problem here, there is a possibility that the phone is pulling some ridiculous amount of current when it goes "on air" (due to a fault) and shutting down.

Also, most batteries now on phones and such, have more than 2 terminals, the extra one possibly being a "sense" connection, to monitor battery temperature or such. If this terminal is left open, (when using a power supply) its also 'possible' that the phone might not work, or might do other strange things due to it not getting a reading from this 3rd terminal.

If this is the case - connect the battery in parallel to the power supply.

Reply to
KLR

Did this phone come off the Arc with Noah? Give it the flick and buy another cheapie.

Cheers, Alan

Reply to
Alan Rutlidge

Hello Allan, while you are having a play around why not test the battery also? The number of milliampere hours may be written on the battery.

Charge your battery pack.

I would use my little constant current charger so I know how many milliamps went in for say 12 hours. Just use your normal charger.

Test the capacity of your battery.

After charging the battery, discharge it by fitting a load resistor to take out 50 or so milliamps and see how many hours the battery voltage holds up. You will have to keep an eye on your voltmeter every hour or so. Work out what the discharge current should be over a ten hour period.

Do a rapid discharge test.

Will the voltage hold up when a load resistor is fitted to draw 200mA, 500mA or more current? Have a play. If the voltage droops quickly there may be a dud cell.

I have an old nokia 5110 and new battery packs are a few dollars to several dollars on ebay if you are willing to try and pick up a bargain. Takes days of trying, you need time on your hands.

Some time ago, while waiting for my new battery packs from ebay to be posted I had a bit of a play with old battery packs. From two dud battery packs I cut open the plastic and removed the dud cells and made one usable pack. Ugly due to exposed cells, but it worked fine.

For a bit more experimenting, the dud cell that was near O Volts even after many hours of low current charging was rejuvenated by a bit of rough treatment. My power supply was set to several volts and the current limit set at a few amps. Passing high current through the dud cell for a few seconds several times seemed to help it recover. I read on the net that this was supposed to remove little metallic growths that short out the cell internally. Seemed to work, to my surprise.

That was a cheapskate exercise but an interesting bit of fun for me anyway to get an old phone battery working again, temporarily that is. :-)

Regards, John Crighton Hornsby

Reply to
John Crighton

Allan. I have a customer who had much the same trouble with a mobile phone. He was told in a phone shop that the phone was faulty.

I connected a bench power supply to the phone, and it worked fine.

I do seem to remember that the neg. terminal on the phone had to be connected to one of the other terminals on the phone to make it think a battery was installed. This is easily worked out my using a volt/ohm meter connected to the battery terminals.

I sold him a new battery I got from WES, and I had a happy customer.

Russell.

Reply to
rg26ce1991

I have had the same problem with a Li-ion battery for a JVC DV camera. The battery charge indicator says the battery is charged but it lasts about 5 minutes, (should normally last for an hour). I have had the battery for about 10-11 months from new.

Purchased a new JVC battery for $110 and now after 18months same thing is happening. Seems to be a common draw back with LIION batts.

Any know cures to extend the life? Will try the suggestion of freezing. The other obvious cure for the camera, is to build a separate battery packfrom cheaper NICads, and use the external power jack. This detracts from the original attraction of this camera, the portability of the thing, the fact it will fit inside a shirt pocket.

Reply to
Gordon

Point taken.

Yes, it has 4 connections, marked:

  • T S
-

Hm... Ok.

Thanks!

Allan.

Reply to
Just Allan

Aw, it's not that bad. It's only about a third of the size of a Nokia

5110 (which most people would recognise). Or about the size of three matchboxes. Often had better reception than other folks with Nokias too - when it worked, that is. ; )
Reply to
Just Allan

I may do this, but even if the phone is ok, the battery has been acting up (I feel) since new. So I'd still a new one if the phone is ok. The reason I say "may" is, my main concern is the phone... Once I know for sure the phone is ok, I'll either sell it on ebay (they only sell for about $30), or, buy a new battery from WES - about $10 + postage.

(YES I'm a cheapskate.) :-p Nah... The main reason I don't want to waste the ~$15 is, someone has given us an Ericson they don't use - and so I'm not in a hurry to risk wasting $15.

There's someone on there selling the battery for $1 - but they're overseas - and after postage - well, you know...

Oh - I see you're one too! : D

Thanks...

Allan.

Reply to
Just Allan

Yep, a new battery from WES is about $10 + $4 postage. But I'm just such a CHEAPSKATE! : )

Reply to
Just Allan

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