There is a lot of stuff in there, and I don't have a clue what makes it tick, I only know it won't if the battery retires! I've cycled mine at least 2 dozen times since I did it, and it works perfect, just like it did when new, so I think I did OK, I saw the guy down under was repairing them, but by the time I paid the shipping both ways, and the repair, I think $50.00 to replace the battery is fair, and finding the correct battery ain't easy, it is "odd" to say the least! Bob