Battery Reconditioner http://www.balenciagatop.com/
Intro: Battery Reconditioner So if you are like this Lazy Old Geek, you have a lot of rechargeable batteries lying around. I wrote another Instructable with some battery tips. Discharge up to 3000mA AA batteries. Charge batteries if possible. I have three chargers. Procedure: NOTE: Most of the AA rechargeables, I've seen are 2500 to 3000mA. Set the switch to high. For A.
Problem: So when I turned on the relays starting to discharge the battery, the battery voltage drops Balenciaga Handbag down. For Stage 1, I am looking for the voltage to drop to 1 Volt but it will do this too quickly.
Cause: The problem is something called battery internal impedance. A battery is not an ideal voltage source (there is actually no such thing in the real world). It has something called internal impedance that can be represented as a resistor as shown in the picture. So the battery voltage and the internal impedance, Ri on the left side of the picture are what the battery looks like electrically. So when the battery is connected to a load, it actually connects the internal impedance in series and makes a voltage divider circuit. Normally this is not a problem as the load resistance is much higher than the internal impedance so the internal impedance is insignificant. However, with a 0.4 ohm load, the internal impedance can become significant.
FYI: Internal impedance is a good indicator of the condition of the battery. The higher the impedance, the worse the battery. If you understand voltage dividers, the higher Ri is that means the voltage across the load is less so it won work as well.
Further complication: This circuit is not an accurate representation of a battery. The internal impedance is not a constant value and changes. It changes with the how much of the battery is discharged and I suspect with temperature.
Solution: My original plan and software was to turn on the relay and keep it on until the battery reach the goal voltage of 1V (Stage1) or 0.4V (Stage2). Well this didn work. So what I did was turn on the relays, leave them on for two minutes, then turn them off and measure the voltage..
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