battery charging??????????

[whitearrow]

good eveing fellas. when is a car battery too far gone to accept a charge? i know a properly charged battery is 12.6 volts. what would be a number on my multi meter that i would say just trade in the battery for a new one. like everybody i want to maximize my time that a bettery will be in service but don't want to waste my time hooking a bettery up to a charger if it won't accept a charge.
thanks,
whitearrow->>>-------->

 

[JHZR2]

100% SOC is more like 12.72 after equalized and no surface charge at reasonable, normal temperatures and conditions.

 

[wrcsixeight]

I have had a couple batteries that will charge up to and hold 12.7+ volts for a couple weeks, but fall to under 12 volts under a light load.

You can't just see a voltage and declare a battery fit for another year.
It doesn't work that way.

 

[fsskier]

I have a very old battery (9 years) with very limited capacity.... you would say it does not accept much charge... but its enough to easily start and run a small outboard. Only enough power to crank a car for about 3 seconds before it gives up the battle, thats why its in a boat.

Its full charge voltage, even after setting for a couple of days is slightly higher then my newest car battery.

Battery condition is much better determined by a load test then it is by an open circuit voltage measurement!!

 

[eljefino]

If you can watch your battery voltage while cranking it should stay above 9 volts with a reasonable outside temperature.

Digital voltmeters only update their displays every half second or so which might not be quick enough.

Is this in a car or something you're deep cycling? Why are you charging it?

 

[morris]

i dont have a garage so iam changing my battery every 2 years. after all its just a battery, its NOT a family member.

 

[mechtech2]

Voltage alone is not enough information.
You need it load tested.

 

[whitearrow]

sorry for the delayed comeback fellas. the battery is in a 50 hp john deere ag tractor. the tractor doesn't get used but maybe 25 hrs a year rite now as it is at my land where we are gonna build a house in about 3 yrs. it will get used more when i am out there all the time. the battery is 6 yrs old and was dragging last year and i had to jump it off for the first bushoggin session.cranked there after but was slow to crank and dragged. this tractor usually fires up pretty fast.
thanks,
whitearrow

 

[hatcoleman]

The six year old battery has lived its life. I would replace it. You have to bring old battery in for core when you buy new battery. Have store test old one first to confirm its bad.

 

[eljefino]

How about if you rotate one of your few years old car batteries into the tractor and get a new car battery? Like for the wife's car?

Heat and vibration kill batteries, cars make heat, tractors vibration. The wear you add to a half used battery will compliment the wear that's already on it.

Use an advance auto code like BIG35 off $85; the party has to end eventually, and batteries are getting pricey.