I had many batteries in my bag of various uses.
I had slotted 5 of two types and sold the rest.
I actually accidently sold more than i wanted too leaving 2 of one type
and 3 of another, which i didn't bother to rebuy back.
The result was that my slotted batterys remained intact at 5 each,
even though i had only 2 of one type and 3 of another.
The bug allowed me to sell the batteries and still retain the slotted ones,
even though they were sold.