Battery Question

[rssnape]

I have a battery bank with 4 12v flooded batteries. They are charged with a 3 stage charger. I have already scolded myself for being in attentive. I checked one battery and there was adequate fluid. I was in a hurry and didn't check the others.
I finally checked all 4. 2 were severely low on water, the other 2 were fine. What causes this situation? Why are they not all low on water?
Thanks
Battery Killer 😡


1997 Tiffen Allegro Bus 37', Cat 3126

[GaryKD]

Hi rssnape,
There are several potential causes, go to
https://mathscinotes.wordpress.com/2...tgassing-math/ for a look at when the battery is overcharged or charged too fast.

The batteries may be connected so the two that are low on water are the first in line to supply power to the coach.

[rssnape]

Battery Killer here. Turns out that the odd thing that I saw on top of one of the batteries was where the top had been blown open. After charging for a while the batteries were getting HOT! One was venting steam out of this crack. Shut the charging down and battery never really cooled down so I'm pretty sure I was experiencing thermal run away. Removed that battery and got it out of the coach. Hopefully the other three will make it through the weekend.
So I am probably going to have to buy some new batteries. Looking at Interstate and Trojan. Any opinions as to which is better? Should I continue with 12 V or switch to 6 V?
Thanks
Battery Killer


1997 Tiffen Allegro Bus 37', Cat 3126

[mgscott4]

Sorry I can't help you with your battery issues. Could the battery have been damaged due to lack of water?

I use 4- 6 volt golf cart batteries and I use this to fill them. It automatically shuts off when full.

Amazon.com: Plews 75-030 Auto Shut Off 2 Quart Capacity Plastic Battery Filler: Automotive


As far 6 volt VS. 12 volt, Search this forum, there are hundreds of pages of information ready for you.

[wa8yxm]

Why will one battery boil dry before the others.....

Even if all your batteries are from the same production run, even if consecutive serial numbers, they are very slight differences.

Also how you connect the batteries to the RV may make a difference.

IE:

RV Battery Battery Battery Battery
v/s Battery Battery RV Battery Battery

(It is called balancing

Or Ground-Battery=battery=battery=battery-RV
(The = (Two parallel lines) sign means a parallel connection)

So what you describe is no surprise.

When you replace your batteries.. Consider this

A group 24 is about 75 amp hours, 4 of them = 300 amp hours
A group 27,, about 95 and thus 380
A group 29 about 105 and thus 420

4 GC-2 Six volt golf car batteries in a series/parallel arrangement (you put two in series makeing 1 12 volt battery and then parallel the two resulting 12 volt, 2 piece batteries) 230 amp hours 460 Total at 12 volt.

Group 31's are about 130 amp ours so you get 520

What size are those 12 volt? The GC2 fits in a Group 24 Tray but is taller.

It is also a true deep cycle (Can recover from a deep discharge better).

[mel s]

Originally Posted by rssnape

I have a battery bank with 4 12v flooded batteries. They are charged with a 3 stage charger. I have already scolded myself for being in attentive. I checked one battery and there was adequate fluid. I was in a hurry and didn't check the others.
I finally checked all 4. 2 were severely low on water, the other 2 were fine. What causes this situation? Why are they not all low on water?
Thanks
Battery Killer ��
1997 Tiffen Allegro Bus 37', Cat 3126

Originally Posted by rssnape

I saw on top of one of the batteries was where the top had been blown open. After charging for a while the batteries were getting HOT! One was venting steam out of this crack.
Battery Killer

rssnape (aka: Battery Killer)
I don't know why they are "not all low on water", but I do know that incorrect charger settings on your inverter/charger can ruin your batteries.
(See your inverter/charger manual for the proper settings).

I have 4 12v flooded house batteries... have shore power nearly all the time, (unless I am traveling or boondocking)... check my electrolyte level every 3 months... and usually only need to add water once a year.
(BTW, my first set of batteries lasted 11 years).

A friend, (with the same Heart Freedom 20 inverter/charger), over heated, boiled out and cracked his new house batteries with the wrong charger settings in less than 3 months.

Which/what inverter/charger do you have?
If your charger settings are adjustable... are the settings correct?

Mel
'96 Safari, 135k miles

[Gary RVRoamer]

If a battery develops a weak cell for whatever reason, it's deterioration will be accelerated as the charger struggles to bring it up to snuff (which is impossible). In effect, it gets overcharged because it never achieves a full charge state. That results in boiling and water loss. The other batteries in parallel with it also get somewhat overcharged, but they can handle it better if in good shape (they don't overheat as much).

That means the low water could be either the chicken or the egg. If water got low for some external reason (hot weather, corroded connection, etc) , continued usage causes more heat and further water loss. Or, if the battery had a bad cell, then the continual overheat from charging causes water loss and the downward spiral continues.

The moral is check the battery water on a regular schedule. If you can't remember to do that, spend the extra bucks to get AGM batteries so that you don't have to do it.

[mel s]

[QUOTE=Gary RVRoamer;2301981 the low water could be either the chicken or the egg. [/QUOTE]

Speaking of the chicken or the egg.
I just ordered both from 2 online sites....so I can find out for sure which comes 1st!

Sorry for the off topic post... (sometimes I have to repeat a joke to keep from crying).

Mel
'96 Safari

[TQ60]

Battery is a term for multiple cells.

And any one can fail just because.

Just be sure your charging system is good and replace the batteries.

Place it on probation for some time...check voltage and water OFTEN to be sure correct and stable.

You may have had a bad cell or an overvoltage condition combined with a weak cell.

Ot demonstration...

Take piece of paper and place 2 tears across it 3/4 wayy across.

Now hold each end in your hands and pull apart.

You will NOT be able to get 3 pieces as one will fail only.

That is the weak cell...others may be bad but one takes the hit.

[rssnape]

Originally Posted by wa8yxm

Why will one battery boil dry before the others.....

Even if all your batteries are from the same production run, even if consecutive serial numbers, they are very slight differences.

Also how you connect the batteries to the RV may make a difference.

IE:

RV Battery Battery Battery Battery
v/s Battery Battery RV Battery Battery

(It is called balancing

Or Ground-Battery=battery=battery=battery-RV
(The = (Two parallel lines) sign means a parallel connection)

So what you describe is no surprise.

When you replace your batteries.. Consider this

A group 24 is about 75 amp hours, 4 of them = 300 amp hours
A group 27,, about 95 and thus 380
A group 29 about 105 and thus 420

4 GC-2 Six volt golf car batteries in a series/parallel arrangement (you put two in series makeing 1 12 volt battery and then parallel the two resulting 12 volt, 2 piece batteries) 230 amp hours 460 Total at 12 volt.

Group 31's are about 130 amp ours so you get 520

What size are those 12 volt? The GC2 fits in a Group 24 Tray but is taller.

It is also a true deep cycle (Can recover from a deep discharge better).

I think my connection may be part of the issue. My RV has a ridiculous number of loads connected to the battery bank. As they all can't connect to one terminal, I have some attached to different terminals with no real reasoning other than what length will reach which terminals and route the "cleanest".
Is there a part that can allow me to attach all my loads in one spot and run a separate cable to the batteries? Perhaps with a fuse?


1997 Tiffen Allegro Bus 37', Cat 3126

[TQ60]

If connected directly to battery then may not disconnect when needed and be a load to discharge.

Also may not be properly fused.

Determine what they are and remedy as needed.

You csn get a 12 volt selenoid like a ford starter type but continous duty to use as a controller.

Distribution panels with built in fuses or breakers for multiple circuits also available so you can relocate them and have minimal wires on battery.

[wa8yxm]

Originally Posted by rssnape

Is there a part that can allow me to attach all my loads in one spot and run a separate cable to the batteries? Perhaps with a fuse?

Yes, it is called a Bus Bar, it is a solid bar of Brass or copper with either has several bolt holes or several tapped holes (usually about a quarter inch) for lug bolts, use matching bolts (Brass) and washers and depending on the length of the bar you can hook up a whole lot of leads. I would put loads in the middle and batteries going out from there one side then the other.

The last two holes are mounted to an insulator, which is then mounted to the RV.

Google BUS BAR

[rssnape]

Originally Posted by wa8yxm

Yes, it is called a Bus Bar, it is a solid bar of Brass or copper with either has several bolt holes or several tapped holes (usually about a quarter inch) for lug bolts, use matching bolts (Brass) and washers and depending on the length of the bar you can hook up a whole lot of leads. I would put loads in the middle and batteries going out from there one side then the other.



The last two holes are mounted to an insulator, which is then mounted to the RV.



Google BUS BAR

Located all the appropriate bus bar, fuse holder, and disconnect switch. Wondering if I should run an individual cable from fuse to each battery or run one and tie the other batteries to each other? Thinking of using one 2/0 cable from the fuse out to the one battery and tie the others with #2. Does this work or should I also use 2/0 to tie the batteries together?


1997 Tiffen Allegro Bus 37', Cat 3126

[rssnape]

Next question. The inverter is a load and a charging source, which side of the disconnect switch should I connect it?


1997 Tiffen Allegro Bus 37', Cat 3126