Mobile phone emergency charger

[ramonegumpert]

Dear Experts

I bought a single-AA battery emergency cell phone charger.

It is rated at :
output : 5.6 v +/- 5%
current : 400ma

I plugged it to my samsung note and the phone detected the current and showed it was charging.

At that time, the battery was charging from 75% level.
After 5 minutes , I checked and found the charging was on-going but the battery level has dropped to 72%.

How could it be so?

I measured the output of the charger and it showed 5.3v at the time it was charging , connected to the phone.

But sometimes, it shows it was only 3.6v and the phone is still showing its being charged.

I was wondering could forum experts give me some clues as to what is happening?

Thanks for reading.

Have a nice day.

Best regards
Ramone :)

 

[The_General]

Well, you should provide further information. If it's really charging at 400mA/5.6V, I would expect your AA battery to be dead in about an hour, excluding any losses.
What's the current flowing from your charger to your phone?
About the voltage drop, in spite of your phone saying it's being charged, that's going to be a very slow recharge. It may have happened due to a drop in your battery voltage.

 

[jim hardy]

repeat your measurements with meter set to measure AC volts.

My guess is the duty cycle changes as AA cell runs down.

just a guess, though

 

[ramonegumpert]

Hi The General and Jim,

Thanks for your comments.

Unfortunately, my amp meter is out of order. I have noted your suggestions. Thanks.



Best regards
Pascal

 

[alphysicist]

Hello Ramone,

It is great that you have purchased an emergency cell phone charger and it is working with your Samsung Note. However, it seems that you are experiencing some issues with the charging process and I will be happy to provide some insights on what could be happening.

Firstly, it is important to note that the output voltage and current of the charger may vary depending on the battery level of your phone and the charging conditions. The output voltage of 5.6v +/- 5% is within the normal range for charging a phone. However, it is possible that the voltage may drop slightly when the battery level is low or when the phone is in use while charging. This could explain the drop in battery level from 75% to 72% after 5 minutes of charging.

Additionally, the output current of 400mA may not be sufficient to fully charge your phone in a short amount of time. It is possible that the charging process is slow and may take longer than expected, especially if you are using your phone while it is charging. This could also explain the drop in battery level.

As for the varying output voltage of the charger, it could be due to the fluctuation in the battery level and charging conditions. It is normal for the voltage to vary slightly, but if it drops significantly to 3.6v, it may indicate a problem with the charger or the connection to the phone. I would suggest checking the connection and making sure it is secure, and if the issue persists, you may need to contact the manufacturer for further assistance.

I hope this helps to clarify some of your concerns. It is always a good idea to monitor the charging process and make sure everything is working properly. If you continue to experience issues, it is best to consult with the manufacturer or a professional to ensure the safety and functionality of your emergency charger.

Best regards,