The voltage from a Running alternator should be between 13.5-14.4V, so i think you Are ok, you might be able to read more if you rev it up some from idle.
There is nothing as a good cheap battery, you get what you pay for, buy a new battery and you Will be ok.

 

The ECM regulates voltage output. If you checked your voltage at the battery with the engine idling, there's little demand placed on the electrical system, so 13.5 volts is sufficient.

Place a load on the system in idle by turning on the high beams, rear defrost and heated seats (if equipped) and retest your voltage. It should jump up a bit.

 

well i checked on oriellyauto.com and their cheapest battery for my jeep is 160 bucks. What are the battery requirements for a 2003 grand cherokee larado so i can find a more affordable one that will work. Thanks

 

I am not familiar with the Brands availeble over there, but Go for a known Brand, Optima, Bosch, most important Are high CCA (cold crank amps).
Also it should have about the same Or better Ah (amphours) as the one in there now.

 

turn on the AC, Radio, lights and re check.
also check the dealer. I occassionally get good deals from dealers on parts with an expiration. If the battery just sits on their shelf eventually the will have to take it as a write off. Particularly now since they dont activate them as they come active..

 

The battery has increased internal resistance from a bad cell which raises its temperature. Late model Jeep, aka Dodge, determine charging voltage by sensing the battery case temperature. A Group 27 has more amp/hr power than the smaller Group 24, mine ran about $160 too. 99% of time a Group 24 will work fine in your mild climate but mounting it securely could be a hassle. I have a Jeep and 2 Dodge trucks - batteries are big expense.

 

The battery has increased internal resistance from a bad cell which raises its temperature. Late model Jeep, aka Dodge, determine charging voltage by sensing the battery case temperature. A Group 27 has more amp/hr power than the smaller Group 24, mine ran about $160 too. 99% of time a Group 24 will work fine in your mild climate but mounting it securely could be a hassle. I have a Jeep and 2 Dodge trucks - batteries are big expense.

Except the WJ battery tray is designed to accept a group 65 battery, plus that group size battery is what the factory designated as meeting all electrical system requirements. A little searching around here will show finicky the electrical system on these vehicles can be due to battery or connection issues.

To the OP:

In the size of battery required for the WJ these days you will have a hard time finding a suitable replacement under $100.

 

I though all WJs came like mine....:rofl::rofl::rofl::rofl:

 

I have an Interstate battery in my Dub. It's been going strong for about 7 years now. I'd stay away from Optima at the moment. I've seen two yellow tops so far that have bulged up from bad quality control issues. And i noticed that it started around the time that production was moved to Mexico. Now don't get me wrong my last name is Sanchez(though i'm actually Apache from a reservation in central America) but a lot of my Jeeps parts say Hecho in Mexico. Or Fabrique en Canada. FYI before people start a argument to be Made in America a Product has to have 75% or more of said product assembled in the U.S. That doesn't mean that all the parts have to be of U.S. origin. And by the bulge comment for the battery i mean they looked like they were getting ready to blow up.:nono:

 

Thanks everyone, I guess i will just spend the money and get a good one. I have just been having a lot of car trouble lately and thought maybe i could get away with a cheaper battery and save some money! I really appreciate everyones help. This forum never lets me down!

 

Thanks everyone, I guess i will just spend the money and get a good one. I have just been having a lot of car trouble lately and thought maybe i could get away with a cheaper battery and save some money! I really appreciate everyones help. This forum never lets me down!

That smoked battery could be the cause of most of your problems. Buck up and get a battery. Considering how low your battery voltage was with engine off 13.5 is expected. That alt may be full fielded trying to get the voltage up and charge the battery at the same time. At idle alternators don't put out their rated capacity.

 

Thanks everyone, I guess i will just spend the money and get a good one. I have just been having a lot of car trouble lately and thought maybe i could get away with a cheaper battery and save some money! I really appreciate everyones help. This forum never lets me down!

Good call. Batteries are still one of the parts that you get what you pay for. Plus given its importance to proper vehicle function its money well spent. Nothing sucks more than a vehicle that won't start.