what size battery does a yamaha warrior 350 take

The Warrior 350 uses a 12‑V, 7‑Ah lead‑acid battery, roughly 150mm x 87mm x 125mm. I swapped mine for an AGM of the same size and it works fine, especially in colder temps. Just make sure the terminals are clean and the mounting bracket lines up. If you go with a sealed AGM, you won't have to check fluid, which is a nice convenience for trail riding.

I had a similar question last year and discovered the OEM part number is YBM‑350. You can source a direct replacement from Yamaha dealers or get a refurbished unit from a local bike shop. One thing to watch: some cheap clones claim the same dimensions but are a bit short on cranking amps, which can make starting on steep inclines a hassle.

I’m hesitant to recommend an AGM unless you’re okay with the slightly higher price. The stock flooded battery is cheap and, if you keep it topped up, it’s perfectly serviceable. Just remember to disconnect it before any long storage periods, otherwise you’ll get sulfation. Also, double‑check the terminal polarity; I once installed it backwards and fried the starter relay.

If you plan on riding in the mountains, consider a battery with higher CCA. I upgraded to a 12‑V, 9‑Ah AGM that fits the same compartment, and the extra power helped on cold mornings. The trade‑off is a bit more weight, but on a Warrior 350 that’s negligible. Also, secure the battery with a nylon strap to prevent it from shifting on rough terrain.

I’d suggest buying a sealed AGM from a reputable brand like Yuasa or Power‑Sport. They’re a bit pricier, but you’ll get a longer lifespan and no maintenance. Just verify the dimensions; some AGM models are a tad taller and won’t close the cover properly. If you’re on a budget, a refurbished flooded battery is fine, but keep an eye on the electrolyte level and replace it sooner rather than later.