Finding Powercells that needs charging

[Jono]

How do I get a grabber to only collect Powercells that needs to be charged?

Code:

extern void object::Findandcharge()
{
object item;
while(true)
{

item=radar(PowerCell);

while ( item.energyLevel < 1 )
{
goto(item.position);
grab();
}
}
}