jordwill41

I have a 2006 is350, base model. A few days ago it completely died and would not start unless being jumped. I bought my battery about 4 months ago and my alternatore has been replaced since then. I had the battery tested and fully charged and everything appeared to be working fine but my IS was still acting up. After about a day it completely died, no lights, no alarm, nothing and my voltage meter says my battery is fully charged but my car acts as if the battery isn't connected at all. I checked my terminals and checked my fuses using a voltage meter and everything appears to be getting power but my car is unresponsive, I've tried both jumping it and charging the battery but it is still unresponsive. I'm very confused as to what the problem could be.

Please help