->  TW>  Unless they are designed for it YES. 

-> Designed for it or not,  you don't wanna leave one in a discharged condition.
-> That's how they get ruined...

Perhaps I didn't make it clear enough. NO rechargable should be left in
a Fully discharges condition for any reason. When it is run down to the
"Low Voltage Limit" it should be placed on the Charger IMMEDIATLY.
And on units set aside for emergencies or infrequently used any wet/gel
cell battery should be topped off Every 3 to 4 months.
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