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### Topic: BATTERIES ARE OVERHEATING.... Please Help! (Read 9053 times)previous topic - next topic

#### prosper50

#15
##### Feb 18, 2012, 04:31 pmLast Edit: Feb 18, 2012, 04:34 pm by prosper50 Reason: 1
Hello All,

Thank you to everyone for your input and suggestions, and sorry for my delay in responding. By reading the tone of some of the responses that I received, it seems that there may be some stress trying to help answer trivial questions from people who are relatively new to the platform, so please understand that I thank you all for your time and your attempts to provide suggestions.

I will try to post a pic later on today, but the battery holder has NO INTERNAL CONNECTIONS between batteries. There are four solder tabs on each side of the holder and each battery is independent of one another. I ordered that specific holder because I had a good idea of what I wanted to accomplish (measuring voltage of each battery independently). And since I only inserted ONE AA battery to test whether this would even work in the first place, the voltage is limited to the 1.3ish volts of the single battery. The battery is not connected in any way to the Arduino (i.e. - to help power the Arduino)... it is totally isolated. Further, this was a rechargeable battery that I happened to have in my desk drawer. Would that make a difference??

Despite the fact of this being impossible, or improbable, etc., I truly have an Arduino Due with TWO wires entering it - one to Analog0 and one to gnd.

As far as the code, I kept it simple.... There are some variable declarations above Main, and then literally three lines of code in the loop section to the effect of:

BatLevel1 = analogRead(bat1Pin);
Voltage1=BatLevel1*4.9/1000.0;
...and a line printing voltage1 to the LCD

Please don't critique the code - it was just to test. I don't have it sitting in front of me and I don't recall exactly what was multiplied or divided, but it was close to that... and the result on the LCD matched the voltmeter reading of the battery +/- .01v or so.

Aside from the unlikeliness of this effect happening, and the ambiguity of my posts without having taken a photo or a code grab before I left the office, my MAIN concern was whether or not something had to be inline between the battery and the Analog0 pin, thinking that the battery might be overheating due to my omission of some important electronic component.

Thanks again!

-Dave

#### cyclegadget

#16
##### Feb 18, 2012, 04:51 pm

Quote
I truly have an Arduino Due

You probably meant to say you have an Arduino Uno. The Due is not available to the public yet.

Is the table you are working on metal or conductive? Could you have set the battery holder on anything that might have shorted it out while you were working with it?

Did this battery come fresh from the charger? Some chargers heat the batteries up, but the batteries are not supposed to be blistering hot.

With your readings being correct while having the battery connected to the Arduino, I have to believe that your connections are correct between battery and Arduino.
Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

#### prosper50

#17
##### Feb 18, 2012, 10:15 pm
My apologies, I was simply abbreviating duemilanove.

No, it is a plastic work surface, and the battery has been sitting in my desk drawer for at least a week (so not fresh off the charger).

#### retrolefty

#18
##### Feb 19, 2012, 01:06 am

My apologies, I was simply abbreviating duemilanove.

No, it is a plastic work surface, and the battery has been sitting in my desk drawer for at least a week (so not fresh off the charger).

So what measurements have you taken with a digital multimeter? If you truly want to solve this 'mystery' then you need to make a series of voltage and current reading while that battery is wired to the arduino.

Lefty

#### prosper50

#19
##### Feb 19, 2012, 01:15 am
Lefty, the extent of my voltage readings related to the accuracy of the voltage on the LCD versus the actual voltage of the battery. They were very similar.      I did not measure current, as it was not even a consideration in my mind (again, my lack of knowledge). I wouldn't know what is suspect or what is the norm.... nor would I really randomly think of where I should be metering with regard to current. Do you have any suggestions??       My background is in user interface design (high level), so aside from the half-dozen explorations I've done with the Arduino platform, I really haven't gone too far, and I certainly don't have an electronics background. I'm trying to learn though, project by project. I find it fascinating and I am enjoying the process, but trying to piece together decades old C programming knowledge, and basic electronics is tough..... the whole old-dog-new-trick thing.    :-)

#### retrolefty

#20
##### Feb 19, 2012, 01:21 am

Lefty, the extent of my voltage readings related to the accuracy of the voltage on the LCD versus the actual voltage of the battery. They were very similar.      I did not measure current, as it was not even a consideration in my mind (again, my lack of knowledge). I wouldn't know what is suspect or what is the norm.... nor would I really randomly think of where I should be metering with regard to current. Do you have any suggestions??       My background is in user interface design (high level), so aside from the half-dozen explorations I've done with the Arduino platform, I really haven't gone too far, and I certainly don't have an electronics background. I'm trying to learn though, project by project. I find it fascinating and I am enjoying the process, but trying to piece together decades old C programming knowledge, and basic electronics is tough..... the whole old-dog-new-trick thing.    :-)

Test 1. Measure the voltage right at the analog input pin you are using and one of the arduino ground pins, write down value and polarity.

Test 2. Wire your current meter in series between the analog input pin you are using and the wire coming from the battery. Have the red meter lead at the analog pin side. Then write down the value and polarity of the reading.

You must of course set up the meter leads and functions properly for measuring voltage and current as they are different and the details depend on your specific meter.

Get back to us with the findings and we will take it from there.

Lefty

#### prosper50

#21
##### Feb 19, 2012, 03:21 pm
Thank you for the explanation, Lefty!
I will perform those tests and let you all know.

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