Battery Boil & Water

[sailorboy1]

With the EQ harge going battery 3 has remained about 0.3V less than the others. So I removed the jumper between 3&4 and the then the voltage between the 2 became the same. Cleaned the ends and measured the ohm on the jumper and reinstalled. The EQ charge was again applied to them and #3 voltage went up, but still to about 0.3V less than #4.

Did the same on 1&2. With the EQ charge going #1 had started being noticeably less than #2. With jumper removed 1&2 voltage became almost the same. Cleaned the jumper and reinstalled. With the EQ charge reapplied #1 voltage lower than #2.

[sailorboy1]

Im done with this thread. I had the caps off all the batteries and watched them bubbling for 3 hours during an EQ charge. #2 isnt really doing anyway much more than the others. Its hard to tell really because there isnt a good way to measure and all visual and other stuff may jot be level, but i think the battery is phyiscally off level with the “problem” being lower. So the cell bubbles up into the cap and runs down the side more than the others.

[ramblinrod]

Originally Posted by sailorboy1

Im done with this thread. I had the caps off all the batteries and watched them bubbling for 3 hours during an EQ charge. #2 isnt really doing anyway much more than the others. Its hard to tell really because there isnt a good way to measure and all visual and other stuff may jot be level, but i think the battery is phyiscally off level with the “problem” being lower. So the cell bubbles up into the cap and runs down the side more than the others.

Electrolyte should not bubble up and out of the cap during normal charging.

Is the cell overfilled?

[Trawlerman]

Originally Posted by a64pilot

Shorted cell would have just that one cell using water, and boiling wouldn’t it?

No, what happens now is that you no longer have two 6 volt batteries in series but rather you now have a 6 volt battery in series with a 4 volt battery and the 4 volt battery is "feeling" too much voltage across it and all its cells are gassing badly thus using water.

[ramblinrod]

Originally Posted by Trawlerman

No, what happens now is that you no longer have two 6 volt batteries in series but rather you now have a 6 volt battery in series with a 4 volt battery and the 4 volt battery is "feeling" too much voltage across it and all its cells are gassing badly thus using water.

Already covered.

The 6 Vdc battery in series will be seeing too high charge voltage
and may gas out excessively as well.

[sailorboy1]

Originally Posted by ramblinrod

Electrolyte should not bubble up and out of the cap during normal charging.

Is the cell overfilled?

Cant be, you said its a shorted cell

[ramblinrod]

Originally Posted by sailorboy1

Cant be, you said its a shorted cell

Har Har!

[thomm225]

Sometimes when the brain has little stimulation it will create it's own world with what seems like real world problems.

It could be time to get out and smell the roses, learn celestial navigation, redo your budget, start a workout program, anything but freaking out over an old battery a couple tenth's of a volt off from the others

[GordMay]

Originally Posted by a64pilot

... I believe you posted you have a hygrometer, have you even measured specific gravities?
I may be mistaken ...

Yep, you are.
A hygrometer is an instrument used to measure the amount of humidity, and water vapour in the atmosphere.
A hydrometer is an instrument used for measuring the relative density, such as specific gravity, of liquids, such as battery electrolyte, based on the concept of buoyancy.

[kenbo]

SB1 poster he has a refractometer and he has also posted the SG of the 12 cells in the bank.

The one thing that hasn't been done is put all 4 cells in parallel and chage them to 7.4v. But that's tough without a power supply.

[sailorboy1]

I dont even know why people are still posting about battery 2 and not battery 3. My theory is that there is more interest in trash posting that the info I've supplied. I even have more info and data, but don't think it is about the original topic. I would start a new thread about that, but have learned that would be just stupid of me.

[mdenize]

Originally Posted by sailorboy1

but i think the battery is phyiscally off level with the “problem” being lower. So the cell bubbles up into the cap and runs down the side more than the others.

Hi Sailor boy, dont give up yet there is gold amongst all the slag heap

I agree the electrolyte should not be lost during normal charging. One thing to make sure is that you only top them right up when they are fully charged...

The reason is the electrolyte expands as it charges reaching a peak at full charge and will overflow losing some of the precious acid if there is not enough reserve capacity.

A better practice is to make sure the plates are at least just covered before charging and then top them up if needed when they are actually charged (the levels will be higher)

[Dockhead]

Originally Posted by sailorboy1

I dont even know why people are still posting about battery 2 and not battery 3. My theory is that there is more interest in trash posting that the info I've supplied. I even have more info and data, but don't think it is about the original topic. I would start a new thread about that, but have learned that would be just stupid of me.

You should just ignore what is not helpful. Amongst the unhelpful comments and wrong information, there are several smart people in this thread who are genuinely interested in the question, and you will get good information if you stick with it. It's a process.

The problem is interesting and I'm glad you posted about it. I am following this thread with interest and have already learned a couple of interesting things. I am also curious about your battery 3.


I don't have much to contribute to this thread, but here's an idea for you -- why don't you swap the positions of batteries 2 and 3 and see what happens? And while you're at it, have a really good look at all the cables, connections, connectors. Remember that the cabling and connections can also cause uneven charging. If the problem is there, then battery 2 will start behaving like battery 3.



Your data shows that you have a big voltage difference so clearly a significant problem which needs to be solved.

[sailorboy1]

I plan to swap #2&3 when i get to it. I cleaned and checked all the cables. Yesterday morning with -102ah and +1amp , so basically at rest with some morning sun, #3&4 had the same voltage. So the voltage imbalance only seems at “high” charge amps. I say “high” as i first measured it at just 8 amps total into bank and would think only around half that were going through 3&4.

Btw- i wonder how many really can do an EQ on their batteries. My charger doesn't do the specified Trojan voltage even on the EQ setting. My solar will do any voltage i program, but it needs full sun to get the batteries there and by the time can get the batteries to real 100% its already mid afternoon.

[a64pilot]

I would imagine most chargers that have an equalization program, that isn’t programmable is not of much use, unless you get lucky and the program matches what you need.
Both my chargers all the voltages can be programmed and are temp compensated, my Magnum which is the only one I have used for equalization is also programmable for duration of the equalization charge.

Charger that was on the boat when I bought it was I believe an old Ferro resonant charger that had two settings, on and off. I have no idea what it’s voltage was.
It surprises me how many people have chargers like that still, ran into a couple the other day with a boat like mine and they are beginning to cruise, they didn’t even know if they had a charger or not, no kidding.