I feel sure that your auto requires at least 3 full quarts of oil for normal operation, and a complete oil change--getting rid of the old oil and replacing it with a new supply of oil--should require at least 3 full quarts of new oil. If a filter change is done at the same time, which it SHOULD be done at every oil change, an additional quart of new oil probably will be required to bring the recommended proper level of oil as shown on the dip stick. If you have a friend who knows how to check the oil level in your engine (stopped and preferably rested for a while) have him or her show you how to do it. If you have had a complete oil change along with a filter change quite recently, the oil on the dip stick should look almost as clear and it did coming out of the new bottles. You HAVE seen what new oil looks like coming right out of the bottle, haven't you? As for the battery question--there are many things to consider, such as;
1. How old is your battery? Is the original (old as your vehicle-- never been changed)?
2. Does your alternator appear to be working properly, by the ampmeter showing charging moderately on the (+) side of center when accessories such as air conditioning, headlight and tail lights, windshield wipers, etc. are operating and the engine is operating at a moderate or more speed; and the ampmeter goes to the (-) side center when such accessories are operating and the engine is allowed to drop to idleing?
3. Checking under the hood, (you need to have someone with you who knows what he/she is looking for and what to do) is there a lot of corrosive build-up around the two terminals on the top of the battery (white & sometimes blueish crusty dried soda-looking deposits)? If there is, the terminals and the wires' connector clamps need, eventually, to be cleaned thoroughly and sprayed with a protective coating (you can find at Wal-Mart automotive) that will greatly slow down the build-up of such deposits again. But before you do that with the old battery. You and your helper friend find someone (if the friend doesn't happen to have one) a vlot/amp meter that will check D/C voltages & amperages. Carefully clean the tops of the two posts on the battery and check to see, with the ignition turned off and the engine not running, what the voltage and amperage readings
across the posts (the positive post should have a (+) sign stenciled into its top and also its the one the RED wire is connected to) are for the battery. If the voltage is a good strong 12 volts and the amperage capacity is a good 50 amps., I believe the batter in its present condition is good--BUT--if the battery is one of the sealed type by which it cannot be inspected for the acid/water level in each of the cells, when put to the task of turning the motor over with the starter several times in succession or for extra-long cranking times, such as in cold weather; it might give out completely when you least expect it and it is the MOST INCONVIENT time. If the battery is 3-4 years old and the voltage and amp. capacity look good but you can't examine the water/acid levels in the cells, I think you'd be wise to get a new one soon. But clean off any corrosion you find around the terminals and wire connector clamps and spray with the protective coating--old or new.