NIMH battery charger tests

In summary, the speaker is interested in testing the effect of -deltaV (drop in voltage) on some NIMH chargers. They have tried connecting a low ohmic resistance in series with a battery to trigger the drop in voltage, but none of the chargers they tested reacted to it. They are wondering if there are other criteria to consider, such as how the charger works or if it has a microprocessor. The speaker also mentions two chargers that use temperature rise detection to determine when the battery is charged.
  • #1
i am intersted in the end of charge detection(-deltaV) on some NIMH chargers, i would like to test that effect on some chargers.
I got some chargers(like GP Smart power bank, GP H500,etc...),all the chargers i have use the drop of voltage as end of charge detection, so what i did is, I connected in serie to a battery a low ohmic resistance, i initiate the charge and after i while a short the resistor ,so drop of voltage but none of the charger did react to that drop,i manage to get a drop of 0.1V but still none of the charger i worked with reacted to that drop, so i would like to know if there are more criteria that i have to take in consideration to generate that drop?
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  • #2
You would have to know how the charger worked.

Microprocessors are so cheap now that the charger may well have one in it.
If it did, the programmer may have got it to do a series of voltage readings over several minutes and tried to detect a gradual decline in voltage which would indicate that the battery was charged.

An instantaneous voltage drop like you produced would not fool it. If it was only taking readings every minute or so, it would not even know you did anything unless you happened to do it when it was taking a reading. Even if it did register, it would look for a further decline in the next minute and so on over several minutes.

I have two chargers that work by detecting a rise in temperature of the battery when it is charged. Each battery sits in a metallic frame that gets hot if the battery gets hot. There would be a thermistor on each one that detects if the temperature varies above ambient.
  • #3

Thank you for sharing your interest in end of charge detection on NIMH battery chargers. It is important to thoroughly test the performance of these chargers, as proper end of charge detection is crucial for the safe and efficient charging of batteries.

In regards to your specific testing method, it is possible that there may be other factors at play that are affecting the detection of the voltage drop. It would be helpful to provide more details about your setup and methodology, such as the specific batteries being used and the exact process for initiating and stopping the charge.

Additionally, there are other criteria that may need to be considered when testing end of charge detection, such as temperature, charging current, and battery age. It may be beneficial to consult the manufacturer's specifications and guidelines for their recommended testing procedures.

Overall, it is important to continue exploring and testing different methods to ensure accurate end of charge detection in NIMH battery chargers. Your efforts in this area can help improve the safety and efficiency of battery charging.

What is a NIMH battery charger test?

A NIMH battery charger test is a scientific method used to evaluate the performance and effectiveness of a charger specifically designed for nickel-metal hydride (NIMH) batteries. It involves measuring various parameters such as charging time, charging capacity, and charging efficiency to determine the charger's performance.

Why is it important to conduct NIMH battery charger tests?

It is important to conduct NIMH battery charger tests to ensure that the charger is functioning properly and is safe to use. These tests also help determine the charger's compatibility with different NIMH batteries and provide insight into its overall performance and efficiency.

What are the parameters measured in NIMH battery charger tests?

The parameters typically measured in NIMH battery charger tests include charging time, charging capacity, charging efficiency, voltage, and temperature. These measurements help determine the charger's performance and safety.

How do NIMH battery charger tests differ from other battery charger tests?

NIMH battery charger tests differ from other battery charger tests in terms of the specific parameters measured and the type of batteries being tested. NIMH batteries have different charging characteristics compared to other types of batteries, so specialized tests are needed to evaluate their performance.

Are there any safety considerations when conducting NIMH battery charger tests?

Yes, safety should always be a top priority when conducting NIMH battery charger tests. It is important to follow proper safety protocols and use appropriate equipment to avoid any potential risks or accidents. It is also recommended to conduct these tests in a controlled environment to minimize any potential hazards.

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