You can try charging the battery for a while to see if that changes anything (and get the 4x4 light to go off). But if it consistently reads around 11.2 volts and if it is the original battery...then you may find yourself stranded sometime in the near future if the battery dips so low that it can't start the vehicle (but may have enough juice to light the interior etc.)...or you may begin to see a few more odd electrical gremlins.
See if you can find a vendor that can load test the battery...which would give you another indication if its time to replace. If it needs to be replaced...you have the option of looking for 49/H8 or 95/H9 class size batteries. The prices can range from just around $100 to well up to $300. But again, the battery class size you're looking for is the 49/H8 and/or 95/H9...with the latter usually costing the most $$$. And don't forget to hook up any replacement battery to the
VENT tube in the battery compartment since it's enclosed.