powering keyfob #1391 with 4 X AA alkaline batteries

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e024576
 
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powering keyfob #1391 with 4 X AA alkaline batteries

Post by e024576 »

Hi,

I'm using key fob #1391 for long term remote data logging, and need to greatly increase the battery life over the standard two CR2016 batteries (or even CR2025 batteries). My plan was simple - solder a 4 X AA battery pack to the key fob's battery terminals. Shockingly, it does not work, that is when a button is pressed the fob on-board LED does not light and no signal is transmitted to the 315 mHz receiver. I have triple checked with a multi-meter that the connections are good. If I go back to 2 X CR2016 batteries everything works fine. I also tried using a voltage divider (150K & 10K resistor) to drop 4 XX AA voltage to 6.04 volts - no improvement.

Any suggestions?

thanks

Paul

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adafruit_support_mike
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by adafruit_support_mike »

That is wierd..

Could you post a photo of how you've made the connections on the board please? I've traced the button input signals in one of those, but have never gone after the power connections. It's possible that the battery clip has some kind of detection switch, or that there's a pull-up/down resistor somewhere.

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e024576
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

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adafruit_support_mike
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by adafruit_support_mike »

Double-check the polarity.

Coin cells are positive on the can (the outer part) and negative on the button (the smaller part). If the CR2032s go into the battery clip button-side up, you'll need to reverse the wires.

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e024576
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by e024576 »

Regarding polarity, see the photo in my Fri Jun 20, 2014 9:25 pm post. Red lead, + is going to the top "arm" and the black lead to the circular base negative terminal. BTW the key fob sold by Adafruit uses two two cr2016 batteries.

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Franklin97355
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by Franklin97355 »

Do you have a picture of it working with the batteries installed?

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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by adafruit_support_mike »

e024576 wrote:Regarding polarity, see the photo in my Fri Jun 20, 2014 9:25 pm post. Red lead, + is going to the top "arm" and the black lead to the circular base negative terminal.
Yes, I saw that. What I didn't see was the orientation of the CR2032 cells while the fob is taking power from those.

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e024576
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by e024576 »

From my June 20 post: "My plan was simple - solder a 4 X AA battery pack to the key fob's battery terminals. " So to be clear the leads are coming from a 4 X AA battery pack. Not CR2032 batteries. And Yes I did check voltage and polarity from the battery pack and it is correct.

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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by IMRon99 »

Why not hack the battery holder to give you 2 sets of 2 batteries for 6 volts in parallel. Achieves the double lifetime you want

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e024576
 
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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by e024576 »

For now I'm just running with the two cr2016 batteries it comes with to see how long they really will last.

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Re: powering keyfob #1391 with 4 X AA alkaline batteries

Post by Franklin97355 »

Could you post a picture with the batteries in?

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