Hello nemanja , that's very interesting what you say... when you say this , is it because of more cases that you have experience with ? I would agree that a bad battery can causes something like this... What does the bad battery mean ? Not capacity enough for powering MOS with some bad ( lower ) level for electronic controls which can be a cause of wrong controlling MOS? The microprocessor's control of many forklift is very smart , lots of sensors , lots of sensing of any more parameters... not enough to stop any bad conditions ? Tell me more if you have anything more to this case , I do not think I would think about some problem with battery , thanks to you I have come to something that can help. At least it is something new what can push me somewhere. Take care , Vlado