Makita circular saw stalling under load - battery or blade?

Hey everyone! I've got a Makita 18V circular saw (the XSS02) that's been giving me trouble. When I'm ripping 2x4s, it keeps stalling out. The blade slows way down and sometimes stops completely. The battery is a 5.0Ah that's about 2 years old. I checked the blade and it's sharp. Could it be the battery or something else? Any help appreciated!

First thing I'd check is the battery. 2 years on a 5.0Ah is about average lifespan if you use it a lot. Does it stall with a fresh battery too? If you've got another pack, try it. Also, make sure the blade isn't binding - sometimes the kerf closes up on pressure-treated lumber. But my money's on the battery losing capacity.

Dave's right. I had a similar issue with my old DeWalt. Turned out one of the cells in the battery was weak. The saw would run fine unloaded but bog down under load. If you have a multimeter, check the voltage under load. If it drops below 15V, the pack is toast. Also, check the brushes if it's a brushed motor - but the XSS02 is brushless, so probably not that.

Before you drop cash on a new battery, try cleaning the contacts on both the battery and the saw. Sometimes sawdust and gunk build up and cause resistance. I've seen that cause stalling. Also, what blade are you using? A cheap combo blade can cause the saw to work harder. Get a good ripping blade with fewer teeth for faster cuts.

Thanks guys! I'll try cleaning the contacts and borrow a buddy's battery to test. The blade is a Diablo 24-tooth framing blade, so I think that's okay. I'll report back.