Went to start my Rouser 180 at Unitop tonight, started to turnover and went completely dead like the battery cable was cut. Checked the battery and the positive side connector had completely corroded away. After scratching the terminal with the wire got a good enough connection to start the bike and drove home. Need the battery terminal cleaned and a new connector soldered onto the cable. I live walking distance to 'downtown' Valencia so a decent local guy is more convenient but will go to Duma if I have to. (off topic, if you have a Rouser and a back problem I found a guy that has riser adapters made so you can install a standard handlebar that helps seating position tremendously. I have a fat bar that is higher, closer to me, and wider than the stock bars, giving me an upright riding position - no more leaning over and better turning leverage.)
Go to the bigger mechanic shop next to the gas station as you are going down the hill in Valencia. You might be able to find the part at the motorcycle parts store just a bit further down the road (you can walk from the main mechanic shop, it has a small canopy in front of the shop where they work on bikes). If they don't have the part you will likely have to go to Dumaguete. The motorcycle shop across from Hotel Essencia (Raddi Parts) will almost certainly have the part you are looking for.
From experience in buying replacement parts here, I doubt you will find just the connector. They will try to sell you an entire cable. But you will find good quality electrical parts at Polaris. A crimp on connector made off copper alloy. then use a electrical contact grease to coat the positive post and connector. If you take the cable there they might even crimp it on for you.
The Robinsons Mall handyman sells the dielectric grease in a small sachet 29 Php it is in the locked cabinet in the automotive section at the bottom of the cabinet.