I have looked for a battery for my S40 in many stores that carry batteries.  I have not found it in stock even once.  Of course, you can have it ordered, but that won't help on the day that it dies on you.  When my '06 hits the 7500 mile checkup point (probably next year), I am thinking of having the local dealer replace the factory battery with a new one while it is in the shop getting its oil and filter changed.  Getting four years out of a motorcycle battery is about all you can expect anyway, right?  My son's sport bike battery wouldn't even last that long.  What do you all think?

Everstart starting batteries are made by any one of the 3 major batt MFGs, Johnson controls, Us Battery, and Excide.
I have 2 everstarts, one as a starting battery in my RV, the other in my pickup. One is 4 yrs old, both are giving good normal service. I would be surprised if they didn't have one that would fit the s-40.

My comment on the longivity of MC batteries is the same as car batteries, ....if they are kept watered, fully charged, preferably on a float charger thru the winter, they have been known to last much longer than 4 yrs.

I just replaced my Odyssey that lasted 7-8 years, and would likely have made it a couple more if my battery had not gone unreplaced for almost 2 years, with a AGM GEL Battery YTX20L-BS (270 CCA).  Got it on ebay for $53 incl shp.  It is for the big HD's.  The one listed for the Savage had 170 CCA.

Jay, yes you can put in an "instant" Walmart replacement -- just be prepared to do some work the first time you do it.

Walmart batteries will send your vent tube off in odd directions and will sometimes put your battery terminals on the "wrong" side -- neither are fatal with a little thought.  

Take all the routing slack out of your battery leads heading to the battery box and you may find you have enough slack to get to the connections on the Walmart battery.  If not, take out some cable and a soldering iron and give yourself the necessary leg room -- to use a generic battery you have to be able to put the connections wherever the generic battery happens to have them.  

Once you have the cable length, you are always prepped for a drop in battery.

The vent tube is easy -- they give you a long clear tube with the battery, so go over the top of the battery to the proper side to run the tube down the battery box.  As long as the tube isn't pinched it can still do its job.

The Savage battery terminal configuration is an odd one that is NOT stocked by many places any more.  Walmart stocks its popular brother, the one with  the + & - in the wrong places.  Mod your Savage a bit and be able to pick up a popular generic battery from anywhere at any time.

Everstart wont quite fit in that battery box, and cables wont reach.
I am re fabbing that battery box so it will work.
But Otherwise its fine for capacity if you get an ES14BS.
Cool.
Srinath.

We were talking the cheaper wet acid type when we are talking cheap replacement battery.

If you want to mod your box to use the bigger ventless battery, that's fine -- but the cost goes up towards the Big Crank price range.

I got a Everstart  since Aug 09 --- been good so far