They claim to last twice as long. And battery is a reserve, not suppose to be the only supply especially when your equipment sucks electricity.
I use my yellow top for a little less than a year so can't really tell you. But I had listen to my music with the OEM JBL more than 5mins. I do experience power drain when rolling down 2 windows and when it hit bottom it draw even more power, but that was with the engine running so I can hear it cranking. I did the same without the engine running and the battery seem to handle it OK. Engine crank right up.
The Yellow Top is lighter and smaller than the OEM battery. So that help cut down the weight a little. But it is not as strong though. Strong enough to get the engine going.
And just in case, I do have a jumper battery in the trunk.
