STI normal running voltage

And that is why I’m 99% sure its the battery. Just wanted to check to see because the voltage seemed low to me for the higher rpms. It could also have just been the battery was still pretty dead. just took it off the trickle charger, but I’ll probably be replacing it tomorrow.

What do you guys recommend for a decent battery. For offroading I always used an optimum yellow top… but what about for these???