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Thread: Cordless Home Phone NiMH mystery: help me before I burn my house down

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    Default Cordless Home Phone NiMH mystery: help me before I burn my house down

    My cordless home phone set is a couple of years old and the batteries are no longer holding a charge. I looked at the batteries and see they are orange Panasonic NiMH AAA, labelled 1.2V min 630mAh. Okay good, I don't need a new phone, I'll get rid of the Panasonics and replace them with some Eneloops, which just lit up the 100% light on my ZTS (sorry, not VM/MM to get exact voltage). So, I put the Eneloops in the phone, and the phone boots up with "Charge for 7h", which is the message when the batteries are nearly completely run down. Weird, I put in new charged batteries and it thinks they're dead? Tried another pair of Eneloops, same thing. So I put it on the charger, and it says it's charging. Batteries are warm but not hot -- though I note some Eneloops I put in the charger are not warm at all. Did I break some weird rule? Why in the world does the phone think my Eneloops are dead if it runs on what appears to be the exact same kind of batteries -- NiMH AAA? Am I risking disaster by putting the phone back on the charger? Obviously, I'm going to keep checking battery temp. Should I just dump the phones and buy new ones?
    Last edited by Joe Talmadge; 10-17-2011 at 12:15 PM.

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    *Flashaholic* Mr Happy's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    When you put new batteries in a phone or other device it is normal to give them a long "balancing and forming" charge as this will prolong their life later on. The phone has detected that you put new batteries in it and initiated the new battery routine. There is nothing to worry about; you will need to let the phone do its thing.
    Tiefer, tiefer, irgendwo in der Tiefe gibt es ein Licht

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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Well that's a relief. I guess I can take off the firefighting equipment. thanks, makes sense

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    Flashaholic* 45/70's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Hi Joe. What I do in situations where the setup "thinks" I've installed new cells, is just go ahead and run the device for a while, without charging it first. In the case of my Panasonic cordless, I can run the phone down until it quits. If the cells are reasonably matched, when the phone actually quits working, the cells are at 1.20/cell, so there is little danger of over discharge/reverse charging occurring, as the "cutoff" voltage is reasonably high.

    Dave

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    Flashaholic* TooManyGizmos's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    ~

    Joe..in your thread title..didn't you mean "cordless" rather than "cell" phone ?

    ~
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Yes, cordless, not cell!

    Dave, the phone did work, probably could have run it down. Seems to be well into the charge phase now, so all's well that ends well I hope! Thanks

    Joe

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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    I thought this thread was going to be about using an old suitcase cell phone battery or something.

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    Flashaholic* TooManyGizmos's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    ~

    Joe ... could you please change the title to say "Cordless" rather than cell ...

    This is not about a cell phone battery. No need for a misleading title .

    Makes Searching for info in titles much more accurate and usefull .

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    Flashaholic* Wrend's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    I don't trust devices that "think" they know more about batteries than I do.

    If the cells are charged and the phone doesn't think they are then the phone isn't accurately assessing the cells' functional voltage levels and will probably maintain them at an overcharged state which will most likely negatively affect their life potential.

    But hey, most people get their batteries for their electronic devices, not the other way around. And they may last long enough for your needs anyway.

    I'm curious though. If you have a multimeter or voltmeter could you let us know what voltage level the cells are being charged to after they're charged in the phone?

    (sorry, not VM/MM to get exact voltage)
    Never mind; I just reread that bit.

    You don't want the cells to get too hot. So if they start to get very warm near where they start to become uncomfortable to hold, definitely stop charging them.
    Last edited by Wrend; 10-16-2011 at 11:42 PM.

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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Typical NiMh batteries. They never seem to last long, no matter what their use is. Not that lithium ions are any better though.
    ampdude

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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    I actually tried as soon as you pointed it out, but didn't find a way to edit anything but the content rather than thread title.. I assume you know a way to change the title? Happy to make it reflect the actual topic

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    *Flashaholic* Mr Happy's Avatar
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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Quote Originally Posted by Joe Talmadge View Post
    I actually tried as soon as you pointed it out, but didn't find a way to edit anything but the content rather than thread title.. I assume you know a way to change the title? Happy to make it reflect the actual topic
    Click the Go Advanced button when editing your post. In Advanced mode you can edit the title.
    Tiefer, tiefer, irgendwo in der Tiefe gibt es ein Licht

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    Default Re: Cell Phone NiMH mystery: help me before I burn my house down

    Post deleted: Mr happy types faster than me
    Last edited by JacobJones; 10-17-2011 at 09:21 AM. Reason: Post deleted

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