Low Voltage Cut Out

mamu;3404143 said:

That would work, but the problem is with the dimming of the LED. Using a shunt regulator (has a built in reference voltage from a zener diode) also does the job. The nice thing is there is no dimming of the LED - the LED is either on or off.

In some of my mods I added a LM431 shunt regulator as a batt status monitor. If the LED lights, batts' voltage is greater than 6.5v. If the LED doesn't light, the batts' voltage is less than 6.5v. At least it lets you know when it's time to charge the batts.

Here's how I wired it in the mod (I used a separate small tactile switch for it, but I guess you could also wire it to the atty switch):

For 6.5 volt indicator:
R1 = 3.3K ohms
R2 = 2K ohms
R3 = 500 ohms
R4 = 500 ohms

Changing R1 will change the volt value. For example, if you wanted a 7.0v indicator, use a 3.6K ohm resistor for R1.

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