Charger problem? Or???

[smokey tennis shoe]

sorry to cut in here, what is a T6 battery?

[Clemsoncartguy]

Originally Posted by smokey tennis shoe

sorry to cut in here, what is a T6 battery?

A model of Trojan batteries.

[Clemsoncartguy]

They say you dont need a load tester as the cart motor is as good a load test as you will put on them and true to the purpose There used for.

[april]

Originally Posted by smokey tennis shoe

sorry to cut in here, what is a T6 battery?

Sorry! T-105, the Trojan battery. T-6 is the motor oil I use in my motorcycles, LOL! My bad.....

[april]

Originally Posted by scottyb

42v during charging is not a red flag. Can you remove the black plate in front and tell us what MODE the charger is set to.
Note that mode 2 is set to turn off at 2.35vpc (volts per cell) times 18 cells = 42.3 volts.
All other modes are higher.
I suspect that one battery is not taking the charge well and letting the others to make up the total voltage to reach the cut off.
Please give a voltage reading for each of the 6 batteries.

Hi guys! Sorry to take so long to continue this troubleshoot; been super busy!
Anyway, the charger is set to mode 2.
And the batteries each read 6.4v when we tested them. We had driven it a little, so not a totally fresh charge, but pretty close. I was actually surprised that they were all the same. I was expecting at least one to be bad to explain the "boiling over" while charging.
We have been using the old Powerwise charger because the DPI still makes the batteries "boil over".
Thoughts? Ideas?

[JohnnieB]

Originally Posted by april

Hi guys! Sorry to take so long to continue this troubleshoot; been super busy!
Anyway, the charger is set to mode 2.
And the batteries each read 6.4v when we tested them. We had driven it a little, so not a totally fresh charge, but pretty close. I was actually surprised that they were all the same. I was expecting at least one to be bad to explain the "boiling over" while charging.
We have been using the old Powerwise charger because the DPI still makes the batteries "boil over".
Thoughts? Ideas?

"Boiling" while charging is normal, "Boiling over" isn't.

The boiling is called gassing and is the result of electrolysis of the water in the electrolyte due to an electrical current flowing through it. Gassing actually occurs throughout the charge cycle, but is only intense enough to be noticed when the on-charge voltage climbs to and goes above about 2.35VPC (Volts per Cell), which is a bit over 42V with a 36V battery pack.

Boiling over occurs when the cells are overfilled. The electrolyte grows as the battery is charged, so if the cells are fill to the correct level when the battery is less than fully charged, the electrolyte may grow enough to overflow when the battery is charged.

Some moisture will collect on top of the batteries because the hydrogen and oxygen gasses that are vented while charging are moisture laden, but no puddles should form.

A properly operating Powerwise charger shuts off when the on-charge voltage climbs to about 45V, which is less than 100% SoC for newer batteries. That cutoff voltage is a compromise between not severely undercharging new batteries while not severely overcharging older batteries.

On the other hand, the DPI charger allows the on-charge voltage to climb unit it ceases to climb during the last stage of the regular charge cycle, fully charging the batteries regardless of age. So the peak on-charge voltage reached using a DPI charge may exceed 45V, up to around 50V or so.

The Yellow LED flashes during the DPI Pre-Qualification test and once those criteria are satisfied, Yellow LED stays on steady and the ammeter climbs to 17A to 20A and stays there until the on-charge voltage reaches 42.3V. Then the DPI switches from a constant current mode to a constant voltage mode and stays at 42.3V while allowing the Amps taper off. When the DPI senses th battery pack has reached about 90% SoC, the Green LED also illuminates and the on-charge voltage is allowed to climb until it stops climbing (More correctly, the rate of voltage change slows to less the something like 4mv/hour/cell - which will vary depending on battery brand selected). When dV/dT (change in Voltage over change in Time) criteria is satisfied, the Yellow LED extinguishes, leaving the Green LED on and the DPI switches into the Float charge mode, which is a steady 39.4V for a 36V pack of Trojan batteries.

[april]

Thanks! That's a great explanation of how the 2 chargers are different.

Is it normal (assuming the cells were overfull) to boil over enough and get so low as to allow the plates to be exposed?
And, why would they boil over if they were full to the correct level?

[JohnnieB]

Originally Posted by april

-------------------
1. Is it normal (assuming the cells were overfull) to boil over enough and get so low as to allow the plates to be exposed?

2. And, why would they boil over if they were full to the correct level?

1. During normal operation (discharging and recharging) water in the electrolyte (diluted sulfuric acid - about 30% by weight) is decomposed into hydrogen and oxygen gases (electrolysis) and escapes into the atmosphere. In addition, the water evaporates and there warmer it is, the faster it evaporates. Between the unavoidable electrolysis and evaporation, the plates will eventually be exposed if water (distilled water only) is not periodically added to the electrolyte.


2. Filled to the correct level is a conditional statement since the electrolyte physically grows in volume as the battery charges. Also, the battery temperature increases while being charged, further increasing the liquid volume inside its cells. In other words, if a battery is filled to the correct level for a fully charged battery when the battery is less than fully charged, it is overfilled and may very likely overflow during the charging process.

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Only add water to batteries when they are fully charged unless the plates are exposed and then only add enough water to cover plates, charge batteries and fill to correct level after the batteries are fully charged.

[april]

Thanks JohnnieB. However, what is happening that I don't understand is why the water in the batteries, filled to the correct, fully charged level as you described, is "boiling over" in one or two chargings to the point where the plates are being exposed in a matter of 2 days. And even with the water low enough that the tops of the plates are exposed, it continues to "boil" out.

I charged the cart with the Powerwise, the voltmeter on the cart read 39+ volts. Checked the water in all batteries -all about half inch to 3/4 inch above the plates. Battery tops are all dry, no smell. I plugged in the DPI and in the first night the batteries are wet and it stinks like sulfur. Used cart, plugged in DPI again for a second night and in the morning the batteries are wet, smells like sulfur and now the tops of some of the plates are just starting to be exposed.

Thanks for all your help, but what am I missing here?

[JohnnieB]

The only thing that comes to mind is that the charger is staying in one of the regular charge phases (Bulk, Absorption and Finish) for some reason.

What LEDs are illuminated on the DPI charger after it has been charging the batteries overnight?

Only the very top (Green) and very bottom (Red) should be illuminated if the charger has completed the regular charge cycle and advanced into the Float charge mode.