Pop quiz: Battery issue

I bought the new used '90 Dodge with a weak or uncharged battery, as the car sat for months. I now have my other good battery in the car. I have been trickle charging the weak one for 2 days. This morning I went down to the garage to unplug it. Before doing so, the input voltage was around 14.6 volts from the charger. THEN I disconnected the battery charger and the voltmeter said 13.23. But then about every second, as I held my test meter on the posts, the voltmeter kept dropping 1/10th volt about every second. Is that a good indication that battery is bad? Or will batteries do that if you leave a voltmeter attached to the + and - post.

I'm sure by tonight, after work, or tomorrow morning, I will actually learn by then if the battery held voltage to about 12.6 volts or not.

But I thought I would ask all you guys this question now, to see if you know the answer to this question, since it is a rather interesting question from the standpoint that many people use voltmeters on batteries to assess their state of charge.

 

Is it a sealed battery? Any way to check the electrolyte level? Do you have a load checker? Mine runs a resistive dead short across the terminals through a gauge and lets you know in a few seconds if the battery will hold a charge or not. It does sound as if your battery is begging for recycling. If it is dropping voltage below 12 volts with only a volt meter attached to it, there's not much hope.

 

Yeah the battery will hold a higher "surface charge" for a bit, but it should gradually taper down and stabilize at the standard 12.6 volts over the course of a few minutes. If it keeps going down below the nominal 12.6 volts, then you might have a bad cell.

 

Do you know - I really don't know? It is one of those batteries that has no raised cell cap covers. Yet, there is a division from the front and back half of the battery - a split, and it has these slots at the far left and far right, as if a place to slip a small screw driver in. I tied to pry up but gave up, since I do not know if these are supposed to come apart.

I have a hydrometer.

I have no such instrument. How much did that cost you and where did you get it?

I left this morning when it was dropping from 13.23 down to about 13.1. I did not want to sit there and wait around to see how far it would drop. I'll find out tonight/tomorrow. As you know I (we? ) should be out working, and not playing on the forum. I should be painting that apartment I started. And going back up in that attic rescrewing/taping duct sections(so I can get stiff joints again).

 

Thanks. I'll keep you al updated. I would like to use that battery to restart my billowing '91, after I drain the water out of it, to prevent possible hydrolock(gasket blew recently, I believe) and gassing out of neighbors. Right now the car is stuck in the garage, taking up space. I stole the good battery out of it to put in my recently purchased '90.

 

Take battery to auto zone or Sears they can check to see if battery is good. Any acid on top of battery will let battery discharge.

 

You mean like if it has some sort of leak?

 

24 hours later: 12.51 volts.

Here is a good one for you. I learned that my next door neighbors car did not even crank over again yesterday. Here he just spent over $200 to get the problem fixed. The garage (get ready) put in a USED starter -for $80! (cost charged for just the starter itself, not labor too -for a tiny 1.6 liter engine). And (get ready) -they never removed the battery cables! They never checked to see if corroded terminals might have been the cause of these sporadic, every 10th time or so, no start conditions? *I* found that for him, this morning. And under the clamp rings was green and white! I told "Bob" that I can see those cables have never had a wrench on them, and the post band that clamps around the post has grit and corrosion at the joint. And I could simply wriggle the cables off the post without a wrench! Absolutely these were not removed by any mechanic. The cable nuts/bolts were rusty and had no marks of a wrench/socket placed on them.

What an incompetant garage, that has employees, sells cars there, tow service, etc.! And "Bob" even bought the car there from him!

"Bob" told me this morning while I remnoved his cables and cleaned them with two kinds of wire brushes and spray treated them, that his lights were dimming at stop signs also. And the mechanic never removed the cables?! How did they remove/replace the starter without doing that? Well, anyoen knows you disconeect the negative cable first. Well, on the battery is a separate cable that has a jack connector. They probably removed that, and that probably did not even feed the starter.

Just thought I'd share. Just another horror story you here about people being either price gouged or incompetent service. Amazing.

 

Ec, the tester cost about $35-50, so taking it to Autozone is cheaper. I just have tractor, car, mower, and diesel batteries to keep up on, so I got one myself. You have a maintenance free battery. You could work for hours on those caps and never get them up. A hydrometer, therefore, would be useless, since you can't get to the liquid.
Not sure how they worked on the starter hot. I guess very carefully. I hate arcing batteries around fuel sources. Could make for a very unhappy day. Not to say anything about the shoddy workmanship on not checking the terminals.

 

Makes sense. You mean..... as in......... ?

Since I already did, I guess you did not have to.