Hi, bought a cheap 12v drill driver £9.99 to wind my stays up n down, but due to it being cheap it had the dreaded old ni cam battery so would perform well when fully charged but you have to drain it to empty before recharging, charge it at half drain and you get the memory kicking in so when you needed it, it would inevitably be flat, not only that but it was big bulky and had to take the charger with you, so invested in one of those tiny 3.5v lithium powered drivers and it works a treat charge it up at the start of the season and I haven't had to charge it up once yet, it's tiny, light and no memory loss,