i just bought the battery tender junior for $24.99 SHIPPED on Ebay. No one else could touch the price and it comes with a one-year warranty. the junior is the 12v charger, so i'm using it for the snowmobile in the summer and quad in the winter. i've heard nothing but positive reviews about them!
Honestly, I run whatever battery I was able to get at the moment - mostly Walmart, lol... BUT I have not yet had to replace even a Walmart battery, in maybe three years on four quads, since I began using Battery Tender Jrs. on each when I'm not riding. Some time ago Bike Bandit had a sale on the BT Jrs. for $17.99... I bought 6.
I have two BT Jrs. on my motorhome batteries also and have had no problems with them in over 5 years.
Yeah I'm starting to think the BT Jr. is the key...One of our local Yamaha dealers is actually doubling the warranty if you buy a BT Jr. with the new battery. Of course another dealer sold me an Optimate 4 Battery Charger/Recover for $65.00 with my last battery.
I use to replace my Battery after every winter up here in Michigan. Bought a Battery Tender2 years ago and solved all my problems. I use to start and let the quads run and ride them a few times in the winter but come spring early summer they would just be junk. The grizzly battery will fit in the Raptor right. I'm gonna get a bigger battery for mine to turn it over, Without the compression release its not liking to fire when its cold and my dad need a battery for his Polaris so gives me a good excuse.