Panasonic Ni-Cd Phone Battery

I have a Panasonic 2.4 ghz phone that uses a 3.6V 850mAh (P-P510 battery). It appears to contain 3x1.2 volt AA's. I was wondering if it would be possible to upgrade the cells to get a longer runtime (I think it's called talktime on phones), or should I just leave it as is? The pack as-is doesn't do bad at all considering it is about 1.5 years old and still gets 2.5ish hours on a charge, but I in the never ending quest for more power I started thinking (which may very well turn out to be a bad thing /ubbthreads/images/graemlins/grin.gif). Let me know what you think. Thanks

-Mike

In terms of increasing the battery capacity, there should be no problems. You could even buy the latest 2100mAh cells and bung them together.

The big question is: What type of charger does it have? Most phones appear to be dumb chargers, so just leaving the phone on the cradle for a bit longer should enable the battery to be fully charged.

But if you have one that is a "smart" charger, then you need to find out how it determines the end of the charge cycle. If it is fixed to expect a lower capacity battery, you won't get the benefits of upgrading to a higher capacity battery.

Anyone who says NiCads don't have memory have never been through two packs in one phone!

I need to get new batteries for two cordless phones, and I think a NimH pack is available for one of them. And I don't believe any of the cordless phones I've ever owned had any sort of 'smart' charger.

If my memory serves, Ni-Mh batteries don't like to be overcharged. I believe that's what killed my 3-month old battery pack made of 3xSanyo 2100mAh Ni-Mh AA cells for a 1st generation Panasonic Gigarange phone. I just had another one made of 3xPanasonic 1100mAh Ni-Cd AAs yesterday. Hope it will last longer this time.

BTW, some Gigarange phones feature battery compartment cover that can be easily removed and reinstalled (i.e. you don't need a coin to open it). With some ingenuity, you can modify the battery compartment to house 3 regular Ni-Mh AA cells. Though you'll have to charge the cells with an external charger, charging time can be shorten to less than 2 hours with a quality charger like the Maha 401. I believe the batteries will also last a lot longer.

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PlayboyJoeShmoe said:
Anyone who says NiCads don't have memory have never been through two packs in one phone!

[/ QUOTE ]

I think your packs died due to constant overcharging, and NOT the DME. Did you ever take the phone off the charger when you weren't using it?

The phone I have appears to be a semi-smart charger... if there is such a thing. I think the cradle just charges until the voltage of the cells is equal to some set point, at which point, the cradle is unable to transfer any more charge and so looks like it has stopped charging.

It appears this way because I leave my phone on the cradle almost all the time (2yrs now) and the cells still provide enough power for those rare, hour-long phone calls and the power indication bar only drops by 1/3. The phone is one of the new DECT (digital) phones and is powered by 2xAAA NiMH cells.

i put nimh in cordless phones all the time and no problems.
i have 2 cmi ss digital that i put 1650 sanyos in 3 years ago.still doing fine.

Okay. I'm holding the pack from a Unisonic 900mhz phone. It is marked 3.6V 600mAh.

I tested the charger unloaded at 11.69V.

The power supply to the phone is 9V 350mAh.

It would seem that this is a fast charger that will indeed COOK a battery if left on it a lot.

Would charging it at lower voltage at 300mAh be any help?

The phone doesn't have any way to tell me battery life, and I am not the only user. So it will remain on the charger a lot.