Cutoff power on low voltage

I have bought Raspberry Pi and solar powered batteries. Raspberry Pi input voltage should be 4.75 V - 5.25 V by specifications. I have tested what happens when the batteries are nearly empty. Raspberry Pi first restarted few times, then lights flickered and SD card went corrupt. I would need a circuit that would cutoff power when it drops to let say about 4.7 V and would give power back when charged to let say about 5.0 V. I would be grateful for any suggestions.

I have posted several low/high voltage cutoff switches on these forums using an LM431, such as in this thread. Use the forum "search" feature to find others.

Thanks.

MikeMl said:

I have posted several low/high voltage cutoff switches on these forums using an LM431, such as in this thread. Use the forum "search" feature to find others.

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You want a circuit with hysteresis otherwise the circuit can still chatter on low battery.

A circuit using hysteresis that goes off at 4.0 volts and wont come on back until the input is >4.8 would do.