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YosemiteBobR · 03-04-2008, 01:52 PM

OK, so I've done a search and have not found what I was looking for. I check my batteries regularly (coach is on my property) and noted while adding distilled water today (check every month) that the two outside cells in one of the four batteries was considerably low while the center cell was right up to the top. I mean below the top of the plates where it should not be. Is this an indication that the battery could be going bad? Or is it just an unusual occurrence.

YosemiteBobR · 03-04-2008, 01:52 PM

OK, so I've done a search and have not found what I was looking for. I check my batteries regularly (coach is on my property) and noted while adding distilled water today (check every month) that the two outside cells in one of the four batteries was considerably low while the center cell was right up to the top. I mean below the top of the plates where it should not be. Is this an indication that the battery could be going bad? Or is it just an unusual occurrence.

Hitchhiker · 03-04-2008, 03:34 PM

Generally, if one cell needs water more often that the others it's indicative that cell is going bad and the battery will fail soon. After a full charge test the specific gravity of each cell with a hydrometer and observe if the cells that use water faster have a lower reading.

YosemiteBobR · 03-04-2008, 04:14 PM

OK, when do you test with the hydrometer. Do you shut the charger off and test a pacific time afterward or can you test immediately?

Hitchhiker · 03-04-2008, 04:20 PM

Turn off the converter after it's had ample time to charge the batteries (unplug the shore power), let it sit for a 10-15 minutes to let the surface charge settle, then check the specific gravity. All should be the same or very close on a good battery.

YosemiteBobR · 03-05-2008, 06:40 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hitchhiker:
Turn off the converter after it's had ample time to charge the batteries (unplug the shore power), let it sit for a 10-15 minutes to let the surface charge settle, then check the specific gravity. All should be the same or very close on a good battery. </div></BLOCKQUOTE>

So here are my numbers: What do ya think. Looks like Bat 1 is bad, but can I change one without changing all the others?

Battery 1
80 deg 1200
80 deg 1275
80 deg 1225

Battery 2
65 deg 1250
65 deg 1250
70 deg 1300

Battery 3
55 deg 1275
50 deg 1275
50 deg 1275

Battery 4
55 deg 1275
55 deg 1275
50 deg 1250

becks · 03-05-2008, 07:08 AM

If one battery is bad you should change all. If not your old one will degrade the new one. This would be recomended whether you have two or three coach batteries.

YosemiteBobR · 03-05-2008, 07:18 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by becks:
If one battery is bad you should change all. If not your old one will degrade the new one. This would be recomended whether you have two or three coach batteries. </div></BLOCKQUOTE>

That makes perfect sense, so I'm assuming that battery 1 is truly bad?

Hitchhiker · 03-05-2008, 07:37 AM

Based on the following chart, battery 1 has a weak cell. The cell reading 1.200 has approximately a 60% charge while the other two cells are 100%. Battery 2, while not as weak as #1, is starting to go.

Batteries 2 and 3 may still have some life but I don't think you'll want to use them with two new ones, maybe you could find another use for those two such as a boat or a golf cart. Maybe a friend's RV that uses two 12v batteries would want to swap the two 6's in.

If you don't boondock a lot you could pull the two weak batteries out and just use the two good ones until they go bad. Then buy all 4 at the same time.

Chart:
<UL TYPE=SQUARE><LI>100% 1.265
<LI>75% 1.225
<LI>50% 1.190
<LI>25% 1.155
<LI>Discharged 1.120[/list]

BryanL · 03-06-2008, 10:27 AM

this sounds like a good case for an equalization charge (the real kind) followed by some desulfation charging.

cannon man · 03-06-2008, 01:09 PM

also check alternator charging rate at the batteries. anything over 14.2 will use water. don't be surprised to see 14.6 or 14.8. workhorse says its ok but the battery people don't like it.

YosemiteBobR · 03-06-2008, 05:23 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Posted March 06, 2008 12:27 PM Hide Post
this sounds like a good case for an equalization charge (the real kind) followed by some desulfation charging.
Posts: 57 | Registered: May 24, 2007

cannon man
Posted March 06, 2008 03:09 PM Hide Post
also check alternator charging rate at the batteries. anything over 14.2 will use water. don't be surprised to see 14.6 or 14.8. workhorse says its ok but the battery people don't like it. </div></BLOCKQUOTE>

I plan on doing the equalization charge tomorrow morning as a matter of fact, for the whole 8 hours. If all else fails I will just remove two of the batteries for now until the last two go bad and replace them all at once. It has been 5 1/2 years so they are due. As far as the alternator, have not had that problem as I charge right at 13.8, but thanks for the thought.

YosemiteBobR · 03-07-2008, 02:42 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by YosemiteBobR:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hitchhiker:
Turn off the converter after it's had ample time to charge the batteries (unplug the shore power), let it sit for a 10-15 minutes to let the surface charge settle, then check the specific gravity. All should be the same or very close on a good battery. </div></BLOCKQUOTE>

So here are my numbers: What do ya think. Looks like Bat 1 is bad, but can I change one without changing all the others?

Battery 1
80 deg 1200
80 deg 1275
80 deg 1225

Battery 2
65 deg 1250
65 deg 1250
70 deg 1300

Battery 3
55 deg 1275
50 deg 1275
50 deg 1275

Battery 4
55 deg 1275
55 deg 1275
50 deg 1250 </div></BLOCKQUOTE>

So, the above were before "EQUALIZATION" and below is after. I did the full cycle of 8 hours and it turned off automatically. I let it set to cool with everything off and took these measurements:

Battery 1
1300
1250
1250

Battery 2
1250
1225
1300

Battery 3
1225
1225
1225

Battery 4
1200
1225
1225

Both the batteries in question 1 and 2 seem to be all over the scale but much higher than previous. Anyone know what that means? At least they are in the "good" area.