Did I overcharge my Battery ???

Sunline1 · 02-26-2009, 04:58 PM

Battery was dead/frozen.

Been charging it slowley with a 8 amp charger, yesterday and today.

yesterday charged it for a few hrs, charger showed 7 amps for most of the approx. 4 hrs. Measured voltage after removing charger yesterday, 12.33 volts. 12 hrs later with bat disconnected all night voltage 12,14 volt this am.

Chargers on most of the day today, amps 7 when put on this am, 4 when charger disconnected this evening. Voltage reading 13.32 volt right after charger disconnected. Will take reading tomorrow am.

Battery is AC Delco, with the magic eye. After charger was on all day today, reading 13.32 volt this evening, magic eye still red ??? Red indicates need to charged. By my calculations the battery should be approx. full charge.

If battery holds charge for the next few days I will try a load test with light in the camper. Thinking maybe it's shot since the magic eye still red.

any thoughts comments etc.

thanks

frank · 02-26-2009, 06:37 PM

I would try a trickle charge for 24-36 hours before throwing in the towel... worth a shot.

Remember that to get an accurate volt reading after a charge, you need to let it rest ~4 hours. You can also load it for a period of time, there's a rule of thumb for that, but I dont recall the figures off the top of my head.

- Frank

henryj · 02-26-2009, 06:55 PM

It's my understanding that a fully charged "12 volt" battery should read 13.6-13.8 volts. AC Delco used a "magic eye" way back in the 60's already that replaced one of the caps. Of course it only gave a reading for that one cell and I believe the newer sealed Delcos also are only reading one cell. The thinking being that if you have one bad cell, you have a bad battery, but if the eye is in a good cell, a battery could still be bad.

Here's a link to a company that makes these eyes that explains how they work and how to read them:
http://www.itwdelpro.com/battery.html

I believe Delco may also have stopped using the eye. My 01 Silverado had one, but the 07 Sierra doesn't. I don't know when they stopped, but it begs the question; how old is your battery?

Henry

henryj · 02-26-2009, 07:12 PM

I just did some more searching on the Internet and came up with tons of information on this page:

http://marine-electronics.net/techar...q/b_faq.htm#12

Buried a long way down is
"4.4.1. Delphi (AC Delco and some Sears DieHard)

Dates are stamped on the cover near one post. The first number is the year. The second character is the month A-M, skipping I. The last two characters indicate geographic areas. Example 0BN3=2000 February."

Henry

Sunline1 · 02-26-2009, 07:22 PM

frank

Thanks for the trickle charger idea, didn't think of that.
Good idea before as you say, throwing in the towel.

henryj

I read the info you supppied on the magic eye (interesting), thank you for it.

My battery was made in 2001, it came with my new 2002 camper I ordered, and specified an AC Delco battery. Took delivery june 2001, one of the first Model#2975 for the new model year I was told.

I'm sure you and most will say it's time for new one and your probably, right.

I will check the volatage reading in the morning and go from there.

If it maintains it's volatage for a few days, I then will do a crude load test
turning on some lights inside the camper, for a specified time and making a ruff calculation as to the amp hrs. etc.

Most likely the battery is shot. Being I have a lot of time on my hands, and the weather has been fairly mild, it gives me an excuse to be outside enjoying the fresh air, "Even if I'am wasting my time".

Thanks All.

Honda03842 · 02-27-2009, 05:42 AM

I believe a fully charged battery should measure 12.6 volts or so. It will read higher immediately after one stops charging because the charge voltage is higher.

As I've said earlier a properly charged and maintained battery can last a long time. Our motorhome's batteries are now 12 years old.

Norm Milliard

Sunline1 · 02-27-2009, 07:02 AM

Honda 03842

I agree a properly maintained/charged battery should last a long time.

Just did my "Crude" load test. Not sure exactly what I learned ? Will research the internet to see what if anyrthing I can find out. As well as any inputs from the "Sunline" family.

Bat Volts disconnected this AM 12 hrs after charger taken off = 13.08

Connected battery turn 24 lights on 21 inside 3 outside I believe they are approx 18 watts ea. My calculation approx. 36 amps. left on a little over 10 min.

Bat Volts with all lights on = 11.9

Bat Volts (right after), all lights turned off = 12.58

Would assume voltage will come up a little after some time, after removing the load.

The only thing I know to do at this time is wait several hours and check bat volt again then check on voltage charge chart.

My calculation is used approx 6 amp hrs. 36 amp X 1/6 hr. (10min) = 6 amp hr. I really could include the paristic drain which I measured, I believe appr .25 amps a while back if my memory serves me correct.
But that's probably neglegable, in comparision to the approx 36 amp load.

Anyone have any thoughts comments (except that I'm crazy), etc

Thanks

Hematite · 02-28-2009, 06:50 AM

Since I have a very low opinion of Delco batteries and you've, amazingly, gotten 8 years of use out of one, I'd tell you to buy a new quality HD battery.

Honda03842 · 02-28-2009, 06:59 AM

And what battery are you suggesting?

Thanks

Norm Milliard

henryj · 02-28-2009, 09:53 AM

Norm, you are right. The number I gave would be a reading while charging with the converter plugged into shore power.

Sunline1, here's another good link for some background. Check especially the table at the bottom of the page:

http://en.wikipedia.org/wiki/Car_battery

Henry

Sunline1 · 02-28-2009, 11:04 AM

Hematite,

just curious why you have a low opion on AC Delco ?
Care to share your reasoning/experience ?

And what battery would you recommend ?

henryj

thanks for the additional info, I checked out the chart at the bottom of the page.

It indicated fullly charged, volts 12.65, my reading this AM was 12.74 volts.

Thanks

Hematite · 02-28-2009, 02:47 PM

In my experience, Delco batteries have always shown shorter life and higher failure rates than other batteries. Again, my experience. I'm sure others have not had that experience or Delco would be out of the battery business. Either that, or I'm more critical of battery quality.

As to recommending a brand, it's pretty much like anything else, there's no point in recommending something because everyone has their favorites. Buy what works for you. Besides, this may all be a moot point because after all is said and done, maybe your battery is alright after all.