Stop circuit from overdischarging 3 NiMHs - 3v zener?

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moeburn
 
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Joined: Fri Jul 19, 2013 12:09 am

Stop circuit from overdischarging 3 NiMHs - 3v zener?

Post by moeburn »

Hello! I'm using three NiMHs, but the circuit overdischarges them to about 0.6v before it finally turns off. Someone told me you should never discharge a NiMH past 1 volt; in fact, the mAh rating on the battery is based on a discharge test to 1v.

So since I'm using 3 batteries, I would want the circuit to be disconnected when the battery voltage reaches 3v or lower. Could I use a 3v zener diode for this? The way I understand a zener diode, is that ALL current/voltage can flow in one direction, but in the other direction, current will only flow if it is above the Zener voltage.

So if I put a 3v zener diode in series with the red positive wire coming out of my battery, it will allow the full 4.2 volts/whatever amps to flow, without any resistance or impedance, until the batteries drop below 3v, then it will open the circuit and stop it from discharging, right?

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