ORIGINAL: tonyc
I had the same set up with a Sig Cap ARF and a Saito 180. Needed about the same amount of nose weight.
Do not mount your battery to the engine mount. Its not that the mount would suffer, but your battery could have a problem. That Saito 180 is a shaker. Batteries hate this. I mounted my battery up against the fire wall and added weight to the motor mount with some epoxy glue.
Tonyc
Yeah I agree, I'd hate to have a connection in the battery pack shake loose. Or worse, the whole battery vibrate off the mount and fall out. The firewall mounts seems like it would be more solid and fool proof. I was trying to get it as far forward as possible to not have to add any more lead but that would be pushing the reliability factor (and increasing the crash factor).