I have a Logitech G7, and love it. I like that when the battery goes low, I can swap out for the spare that's in the receiver, and recharge the dead one. It's getting old, and the batteries aren't holding a charge, so I think it's time to replace it. I'm a bit dubious about the replacement OEM batteries online. Any suggestions? While I don't use that system as much as I used to, I don't want to get stuck with a dead battery, but don't want to have to put trips in it either.