Hi,

I think my battery is bad even though it's 3.5 yrs old and it's a 84 month battery. It is only reading 11.77V on my multimeter. when i go to start it it barely trys to turn over followed by the starter clicking noise. I tried jumping it and that didn't even get it going. The cables seem fine, the ground it attached well, cable going to starter looks fine and it's not terribly dirty or anything. the only other thing i was thinking is that maybe the alternator isn't charging the battery properly, but i think i need to get it started and get a reading with it running to identify that. Took the battery out and have it sitting on a charger right now, but expecting to have to replace. Any suggestions out there. Am i possibly missing something? thanks in advance.

chris

 

give it a good charge, put it back in and it should start. then get a voltage reading while running. if its in the 12's then the alternator isn't charging. you should be around 13.5 to 14.5 when its running.

 

had in on a charger for about 7 hours and it would only charge up to 11.95V. was hoping for mid 12's or so. i don't think it will start with that voltage, any opinions?

 

your best bet is just get a new battery it sounds like its dead maybe take ur alternator off and get it tested at the parts store

 

Do not know where you are located, but Costo Wholesale has the best prices on batteries.

 

first buy new battery. optimas are the ones to buy.

second with new battery in start jeep.

third remove battery cables. (will let you know if the alternator is charging or not).

just my .02!!

 

Sorry to say Seth but, NOOOO!!!!! dont do that.
Dont remove the battery cables while its running EVER!! The right way to check if the alternator is charging is with a multi meeter. The easiest way to see whats going on is to set the multi meter to Volts and put the 2 leads on the battery. Check the volts when the car is not running. Then with someone in the rig have them turn the key to start it. See if the battery drops allot. Then check to see what the volts are when the jeep is running. It should be around 14 volts while running. The battery may just have a bad plate in it or "cell". It might even start your jeep up with it that way but its still bad. I used to race electric cars so I know a few things about batteries. The Optima red top is a good battery but not necessary. Any Interstate is good though. Whew long winded huh!

P.S. Test your battery first before mindlessly replacing it. Make sure to clean them cables good.

 

ya, as long as your charger is working, after 7 hrs you should have been over 12 volts. possible bad cell, you won't get any good answers about your alternator with that battery. get a new one

batteries these days are a pain, there are way more crap batteries than good. the only two i've seen do any good are optima, and interstate.

 

check the water level in the battery.

 

I believe they are both made by the same company. My friend use to work for interstate. Top of the line battery IMO.

I have actually had good luck with Ford Motor Company batteries. Over 9 years of constant daily use out of multiple batteries.

 

Buy a optima....

 

Wait!

Before you guys go to buy an optima, if there is a interstate warehouse is anywhere near you call them and ask if they have any "BLEM" red top optima batteries. They are usually way cheaper.

 

thanks for the input guys. Going to replace the battery, then check the voltage to make sure my alternator is charging properly. providing the new battery get's it started that is.

 

If you don't have interstate by you(yea right) head to advance auto parts if you are near one. They carry a house brand made by Johnson control(makers of interstate, optima, and AC Delco) called Autocraft. The warranties on the autocraft are just a little better, and in many cases, cost less.

 

i agree with you use a multimeter. but if you dont own one like i didnt when i was 17 we would pull the cables off for 30 seconds to double check the alternator. optima red top is very necessary if it gets to be below zero in temperature. my wife car with an interstate battery didnt start whe we had very cold weather but mine did every time. clean your cables really good like the man said.

ps good call on the bad cell. i didnt know that could happen.