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leadman · 02-19-2019, 08:18 AM

When you get the batteries out and the caps off carefully look into the cells with a flashlight. If a cell seems to have more bubbles coming out of it the possibility it is bad is good. Also look for a brown color like dirt in the cells. This is lead sulfide, which looks just like dirt but heavier, and is caused by overcharging the batteries or age. Eventually this settles in the bottom of the cell shorting out the plates when it gets deep enough.
I have yet to see one of the automatic fillers that does not overfill the cells in my 50 years of working on vehicles to include 17 years as a Shop Foreman. Many believe that the level should be to the bottom ring of the battery top in the cell. This is too full and the level is fine at 1/4" above the plates. With the level to the ring there is little room for the cell to off-gas in areas of the cell not directly in the opening. This results in pressure carrying the electrolyte out of the cell.
The best test of the batteries is to get them load tested. One of the glass tube testers with the floating balls in it is easy to use and if understood how it works can help in locating bad cells. If you see discolored electrolyte in the tube this is not good.

chunker · 02-20-2019, 04:35 AM

Quote:

Originally Posted by leadman

When you get the batteries out and the caps off carefully look into the cells with a flashlight. If a cell seems to have more bubbles coming out of it the possibility it is bad is good. Also look for a brown color like dirt in the cells. This is lead sulfide, which looks just like dirt but heavier, and is caused by overcharging the batteries or age. Eventually this settles in the bottom of the cell shorting out the plates when it gets deep enough.
I have yet to see one of the automatic fillers that does not overfill the cells in my 50 years of working on vehicles to include 17 years as a Shop Foreman. Many believe that the level should be to the bottom ring of the battery top in the cell. This is too full and the level is fine at 1/4" above the plates. With the level to the ring there is little room for the cell to off-gas in areas of the cell not directly in the opening. This results in pressure carrying the electrolyte out of the cell.
The best test of the batteries is to get them load tested. One of the glass tube testers with the floating balls in it is easy to use and if understood how it works can help in locating bad cells. If you see discolored electrolyte in the tube this is not good.

Just to be clear to everyone, you are talking about 2 different tests. The load tester can check the ability of a whole battery to accept and hold a charge. The "glass tube tester" is a hydrometer used to test specific gravity of an individual cell. Only possible to do with a flooded cell that's not maintenance free.

lwmcguire · 02-20-2019, 07:55 AM

Quote:

Originally Posted by drwwicks

Just to be clear to everyone, you are talking about 2 different tests. The load tester can check the ability of a whole battery to accept and hold a charge. The "glass tube tester" is a hydrometer used to test specific gravity of an individual cell. Only possible to do with a flooded cell that's not maintenance free.

Great clarification, I use a Sun tester that is getting grey but works well

If you don't have one or can't easily get your hands on a load tester simply charge up the batteries, apply a heavy load using the invertor for at least 15 minutes, then test the battery voltages separately. The low voltage battery is the weakest. this never fails

You do not have to lift the cables to test the voltage

twinboat · 02-20-2019, 09:32 AM

Quote:

Originally Posted by lwmcguire

Great clarification, I use a Sun tester that is getting grey but works well

If you don't have one or can't easily get your hands on a load tester simply charge up the batteries, apply a heavy load using the invertor for at least 15 minutes, then test the battery voltages separately. The low voltage battery is the weakest. this never fails

You do not have to lift the cables to test the voltage

You need to lift ( disconnect ) parallel battery cables, otherwise your testing both.

Load testing deep cycle batteries with a CCA battery tester will tell you if they are OK to use, but not how much capacity they have left.

AHs are measured with a specific load for a specific time. A 100 AH battery @ the 20 hour rate = 5 amp draw for 20 hours, and still read 10.5 volts. You can cut the 20 hours to 10 and see if it stays above 12.06 volts.

An older 100 AH battery may test fine with a load test, but only suppy 50 AH.

Mark_K5LXP · 02-20-2019, 09:59 AM

Quote:

Originally Posted by twinboat

A 100 AH battery @ the 20 hour rate = 5 amp draw for 20 hours, and still read 10.5 volts. You can cut the 20 hours to 10 and see if it stays above 12.06 volts.

As a battery gets older it gets "softer" and I find the discharge curve isn't linear, so picking the midpoint voltage isn't set in stone. What voltage it has under load is also going to move around a bit based on age and capacity. It could be argued if it's not at capacity at the 50% point it won't be at the 20% point either but I like running them down to 10.5V at the 20hr rate just so I have the real number. Sometimes data sheets will show capacities at other rates so if a shorter one is available I will use that sometimes. But the 20 hour rate I think will be more accurate.

As far as using an inverter as a load, some will sense a drop in input voltage and adjust input current to compensate, so it's useful to know that depending on the inverter it could be either like a resistance (current goes down with voltage) or constant power (current goes up as voltage comes down). Doesn't affect the test in a huge way and if you do it the same way each time the baseline is valid, but switching from one to the other will affect the run time.

Mark B.
Albuquerque, NM

Persistent · 02-20-2019, 10:09 AM

I don't have any problem maintaining my battery bank. In many years I have not found even the slightest damage around my batteries. Never had a problem maintaining water level.
I sold my first pair of GEL's with the TT last year. Worked the same as when I bought them 11 years before. My latest pair of AGM's are doing fine.
The GEL's were charged and maintained using a single stage constant voltage converter that applied a top voltage of 13.3 volts. I never let the static test voltage drop below 12.7 in storage. A couple of times they were accidentally drawn down flat.
My new TT has a three stage WFCO and switches to 13.2 after 4 days when there is no change in current. It charges from 20% to full much faster. I will check back with you in a few years to update.

reubenray · 08-12-2019, 07:49 AM

I thought I had this problem solved, but while getting ready for a trip I went to check my water levels in the batteries. There is corrosion all over the tray again, but worse. The metal clips for the straps are gone or broken. Now I have no option, but to take out all of my batteries and figure out what is wrong. I did check my charger and they are not being over charged.

I need to get some more clips and straps plus a battery carrier to remove the batteries. I have two little brackets on top of the batteries. It looks like this https://www.amazon.com/TROJAN-609628...72429883&psc=1 will work.

I plan on taking pictures to see how the cabling is one plus I will number the batteries to make sure I put them back in the correct spot.

One key question is what do I need to do with the electrical system prior to removing the batteries?

mobilemike · 08-12-2019, 10:34 AM

Quote:

Originally Posted by reubenray

I thought I had this problem solved, but while getting ready for a trip I went to check my water levels in the batteries. There is corrosion all over the tray again, but worse. The metal clips for the straps are gone or broken. Now I have no option, but to take out all of my batteries and figure out what is wrong. I did check my charger and they are not being over charged.

I need to get some more clips and straps plus a battery carrier to remove the batteries. I have two little brackets on top of the batteries. It looks like this https://www.amazon.com/TROJAN-609628...72429883&psc=1 will work.

I plan on taking pictures to see how the cabling is one plus I will number the batteries to make sure I put them back in the correct spot.

One key question is what do I need to do with the electrical system prior to removing the batteries?

The first thing you need to do is spread baking soda over the batteries and battery tray. That will neutralize the acid. keep adding more soda until it does not fizz anymore . Then you can wash the area with clean water. Then remove the cables and pull the batteries.

reubenray · 08-12-2019, 01:40 PM

Quote:

Originally Posted by mobilemike

The first thing you need to do is spread baking soda over the batteries and battery tray. That will neutralize the acid. keep adding more soda until it does not fizz anymore . Then you can wash the area with clean water. Then remove the cables and pull the batteries.

I have very little corrosion on my cables (one cable). The corrosion is on the strap clips and down the side of the batteries.

mobilemike · 08-12-2019, 08:29 PM

You will still need to neutralize it. Any water on the dried acid will reactivate it.

reubenray · 08-13-2019, 05:18 AM

Quote:

Originally Posted by mobilemike

You will still need to neutralize it. Any water on the dried acid will reactivate it.

I plan on doing that today if my wife has some baking soda to spare.

leadman · 08-13-2019, 06:28 AM

The lifting straps should not be left on the batteries when you are not lifting them. The cheap steel clips will corrode very fast.

I think the best thing for you to do is to remove the batteries and get them load tested.
Make sure the battery cells are not too full. A quarter inch above the plates is where it should be.

If they test good and the cells not too full then have your charging system looked at.

I don't recall if you have solar or not, but there are some controllers that do not shut off and will overcharge the batteries if left on.

leadman · 08-13-2019, 06:37 AM

drwicks, the glass tube tester with the floating balls can be a useful tool if one knows what it is telling you.
If all the cells in the battery except one float all the balls then there is a high probability that that cell is bad. We tested this method against a Motorola battery tester many years ago and it gave the same results.
I have also disassembled many batteries over the years and found that this method and the visual inspection confirmed the issue with the cell.

We had 4500 vehicles and pieces of equipment in our fleet and 1500 of those were assigned to the shop I was a foreman in. Plenty of batteries to test and play around with.