Battery question

[Wizzel]

I'm in the process of testing my batteries and these are the results. Can you guys help me decipher? The 2 on the right are reading 5.9 on my multimeter. the one 2nd from left is reading 5.7. However, the one on the far left is not giving a steady reading and is all over the place and generally reading low. I'm assuming the 3 on the right are good and I've got a bad one on the left? The battery reading on my panel is generally 2 out of 4 dots and I find that I'm having to start the rig up in order to start my generator. I'm assuming these are symptoms of my bad coach battery. I ran my generator for several hours yesterday btw. Thanks

[camaraderie]

Before testing...did you FULLY charge them overnight on your charger...then disconnect them removing them from the coach wires and each other for at least 12-24 hours from everything before you took your readings? If not...your readings are bogus.
Anything less than 6.3 AFTER you have done the first paragraph steps indicates some loss of capacity. Anything less than 6.1 should probably be replaced...definitely if 6.0 or below. If you are getting readings in the 5's after fully charging them AND disconnecting them from the coach...even without waiting 12 hours...they are toast. Without knowing about your battery charger, my guess is that you didn't run it nearly enough to charge the batteries fully.
You have roughly 450 amp hours of batteries there and if deeply discharged you could be needing to replace 300 of those...even with a 100 amp charger that is a minimum of 5-6 hours plugged in or running the genny and most coaches don't have 100 amp chargers.

[Libero]

I would think your batteries are toast.

Did you check the electrolyte level and then measure the Spefic Gravity with a hydrometer?

Less than 5,8v indicates they are less than 25% charged and if you had the gen on yesterday for several hours and this is all you measure, well I would just buy new batteries.

However you could take the best pair and put on charge and see what happens.

Good luck

[Girardet]

Try This
The 12volt Side of Life (Part 1)

[vsheetz]

Ensure properly charged then check with hydrometer. A load check is good too. Some auto parts store may do this for you.

[YC1]

What was the voltage across the bank when charging?

As suggested, a hydrometer will tell you a lot about them but they need to be charged fully.

[Wizzel]

Thanks! I've pulled them out and am charging them up in order to find out what I've got. I had previousy checked water level and topped off so that part is fine. Until now I was under the mistaken impression that driving the rig or running the generator would bring me up to full charge.

[targaboat]

The fluctuation in voltage measurement is strange. It can be where from 0 to 6.5 volts but not fluctuating. Sounds like a bad connection to me and maybe nothing wrong with battery. Also could account for not getting charged up.

[Arch Hoagland]

Fluctuating voltage is most unusual but could be a sign of a broken post.

A hydrometer is about $10 and well worth the cost.

How old are the batteries?

[Wizzel]

Two batteries are from late '09 and the other two from early '10. I'm uncertain as to where the water/acid level should be. Currently the water is at the top just touching the filler tube. Hopefully you can see in the picture. Is this correct? It's going to take awhile for me to charge all 4 but I'll follow up and let you all know. Many thanks

[Wizzel]

Well I replaced 2 of them today and attempting to charge the 2 that were in better shape but not all that hopeful. After 8 hours of charging things were looking up but the voltage appears to be dropping over time into the low 6's.

[camaraderie]

Originally Posted by Wizzel

Currently the water is at the top just touching the filler tube.

It's hard to see the water in your photo but you can see the slot cut in the orange filler tube and the water should be right at the bottom of that slot. Any higher than the top of that slot and you are over filled.

Not a good idea to mix old and new batteries especially if the old ones are nearing end of useful life. Suggest replacing all 4 now even if the one's you are still charging are still useful.

[Wizzel]

Compared to the new ones the water is fine but good to know that I shouldn't mix and match batteries. Looks like I'll swap the other two tomorrow. Thanks

[YC1]

Originally Posted by Wizzel

Well I replaced 2 of them today and attempting to charge the 2 that were in better shape but not all that hopeful. After 8 hours of charging things were looking up but the voltage appears to be dropping over time into the low 6's.

What is the voltage WHILE charging?