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Answering Machine Backup Batt

Hello, all. I've got an ~8 year old GE brand answering machine (like this one:

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that has worked flawlessly until about a month ago when the machine announced "Low battery". As usual I replaced the 9v batt with a fresh one and the announcement was gone. The next day I got the message again. Took out the battery and checked with a VOM (yea I know it wasn't under load) and the terminal voltage was only about 6 volts. Put in another fresh battery and got the same results after a day. Prior to all this the battery would last for at least a year without needing to be replaced. In all other respects the device works fine but with a nearly exhausted (or no battery) the box resets to defaults if the power from the wall wart adapter is interrupted.

Any ideas what could be pulling the battery prematurely low? Thanks for your time and comment. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood
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At the risk of being simple minded, I see a couple posible reasons:

1) Low quality battery, doesn't have much energy to begin with. 1a) You do use alkalines, yes?

2) Problem with the machine, excess current draw. Possibly dried out capacitor.

2a) I don't know the normal current draw. But with a VOM and devices using 9 volt battery clips, not hard to check current draw.

. Christopher A. Young You do learn more about Jesus, yes? .

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(Lots of power.) . .

Reply to
Stormin Mormon

Thanks for the quick turnaround, Stormin. (So use to you being over at the locksmithing ng.) I did try fresh 9V alkalines. I wouldn't think a dried-out cap would be a problem, but what about a leaky cap? A VOM in series with the batt connected to the answering machine indicated a current draw of less than 1 mA with the AC adapter connected. I'm wondering why there should be any current drawn from the batt when powering from AC. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood

I can believe that the battery would run down if it is being used. Check to see if the machine is plugged in and getting electricity. Maybe a bad socket?

Dave M.

Reply to
David L. Martel

Quite all right. Woke up, check the messages, and there you are! I still follow the locksmith NG, but much less action there.

I'm unsure about dried out or leaky cap. The one man I know who would instantly be able to answer that.... died about a month ago.

Also don't know about the 1 mA current draw. Wish I were more help.

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. 
Christopher A. Young
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Reply to
Stormin Mormon

Hello, and the device won't operate on battery alone. The battery is just a backup to maintain the user-specified configuration in memory in case of AC power outage. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood

J. B.-

I would expect there to be an isolation diode between the battery and the AC adapter's power. I can think of three possibilities:

  1. The diode is shorted, so power from the AC adapter is ruining the backup battery.

  1. There is a leaky electrolytic capacitor on the battery side of the diode. Check current draw from the battery with the AC adapter disconnected.

  2. The AC adapter has failed, so the device is being powered entirely from the battery. Does it work with the battery removed?

Fred

Reply to
Fred McKenzie

Thanks for the reply. Wrt to 3) the battery provides for retaining the user-specified configuration (outgoing message, current time/date, etc) in memory in case of an AC power outage; the unit still requires the AC adapter to operate with or without a battery installed. Without a battery (or too low a battery) the unit will reset to its out-of-the-box defaults following an AC power interruption. Just like a lot of those bedside LED alarm clocks with battery-backup. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood

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