Battery Question

[xczar]

Original owner of a 97 4W 2dr Yukon. I drive it about once a week now as the price of gas has me garaged most of the time. Noticed, maybe the battery struggling to turn over for a bit for a while, then just yesterday, dim lights and nothing to get the starter going. I tested the battery at about only 8V. Then charged it connected to the truck to 12.42V (Charger automatically shuts off), then disconnected from the truck, and it has slowly dropped in volts to 12.18V now.

Can I conclude the battery is definitely bad? Just get a new battery, then test the altinator? I installed a new alt about 3-4 years ago.

BTW, I have been using Gold DieHard's for the last 10 years or so. The last one died after only 2 years and got this replacement that is doing bad now. It is also about 2+ years old. Anyone with godd or bad experiance with these DieHard's?

Xczar

 

[SunlitComet]

what is you weather like in your area? charge it up again, 12.8 volts is a totally good voltage, then load test the battery. if it fails load test then replace it. make sure your don't have excessive parasitic drains and the acid levels in the battery are well maintained. if you are in storage mode a lot then consider a battery maintainer. try to stick with one under the sears or interstate battery brand names as manufactures typically tune their designs to their own products and those are the ideal batteries to have these days. other bands that are well reviewed can be used to.

btw, when you disconnect a charging current the voltage will always settle a bit. your numbers on charging are totally fine.

 

[Slice]

^1+

Your battery is definitely done. I sell batteries for a living it does not even leave the warehouse under 12.7 volts. If you have access to a carbon pile load tester that would give you an extact answer. But from my experience I would say its time for a new battery. You should definitely get some sort of maintainer to keep the voltage up if its going to sit for awhile. Look into Noco Genius( part # G1100 or G3500)I sell a ton of there products and have great success with them.

 

[xczar]

Now several hours later and it is down further to 12.16V.

I thought the correct charge would be about 12.7 as Slice mentioned. Much over that would be a over charge? But more importantly, the voltage should not drop too much, at least not to 12.16?

I will check again in the morning to see if it continues to slide. Appreciate any thoughts, as I have to be as frugal as possible like most Americans, too much of my funds have to take care of other countries and their citizens along with my TRUCK!

 

[SunlitComet]

free battery load testing at parts stores.

 

[xczar]

Battery went down just a bit to 12.15 this morning. Are batteries susceptible to these very slow drains when they go bad? I connected it back to the truck and put a load tester on it (one of those cheaper hand held Chicago brand battery testers but seems like it could be accurate?). The load test was just a hair or two below acceptable at 11.10V. I figure before I replace it, I would try to get a bit more juice into it with a 2A charge for a few hours. Still bothering me my charger only got it to 12.42V initially with the 15A charge. My charger has a auto shut off, hope it doesn't effect the proper amount getting in the battery.

Should it matter in any way if the battery is connected to the truck when charging? Nothing to connect the charging clamps to when the wire posts are pulled from the battery. Also, how important is it to charge, or jump a vehicle for that matter, with the ground to the chassis or motor?

Hope to understand this a bit more, thanks for the thoughts.

 

[ccapehartusarmyINF.(ret)]

if it dropped to 12.15 volts when its not connected to the truck its no good

 

[SunlitComet]

does not sound really that bad but those load devices typically only put on a 100-150 amp load. you want to put about 300-350 amps of a load to(used to test stock oem batteries) simulate a a very cold engine start. or you can go to pats stores to do it. there methods vary as to how they test it.