During the recent Webinar there were some questions around sulfation & equalizing batteries so I wanted to post some more information here.
What is "Equalizing" or a "Conditioning Charge"?
Equalization - A low current, high voltage controlled over charge of the battery.
Equalization or conditioning charges can help to:
* Balance the individual cells of a battery so that the voltages in each cell are closer to equal and the specific gravity is also closer equal across all cells.
* Reverse or help to shed the formation of hard lead sulfate on the and in the battery plates.
* Eliminate stratification effects where the acid concentration is weak on top and more concentrated down low in the battery.
Sulfation = Cancer of the Battery
Once the cancer has begun it is only a matter of time before the banks demise.
Equalization = Chemotherapy:
While equalization can help it can lead to other damaging effects and should only be used when absolutely necessary. Equalization can lead to errosion of the positive and negative plates which also reduces battery life. It is best not to do it "automatically" or too often. Only equalize on an as needed basis and turn off any auto equalization functions, if you can..
When should I equalize?
* When specific gravity (SG) & open circuit voltage do not agree
* When SG across cells varies more than .030 (.050 difference is a bad battery)
* When an individual cell requires more or less water than the others
* When you notice capacity loss
* When your wet cell batteries have sat for 2+ months without a charge or 5+/- months for Lifeline AGM
* Do not over equalize
* Follow your manufacturers guide-lines for equalization
* Use a PROPER charger that has a dedicated equalization mode. This is CRITICAL. Cheap chargers and "equalization" are not like bread and butter they DO NOT go well together.
* Most good quality marine chargers will do a separate controlled equalization at 15.3 - 16.0 volts, and low current, around 1.5% to 3.5% of the battery capacity. Do not buy a charger that puts out a 16V non-adjustable equalization voltage if you have batteries that require a limit of 15.5V etc. etc.. When shopping for a charger look at the specs of your batteries and your charger.
* Many chargers, such as Xantrex, time out the equalization mode at 1 hour. Your batteries may require more equalization and this "time out" allows you to test SG/Voltage etc. and then re-equalize if necessary.
What is Sulfation?
Sulfation = The formation of hard lead sulfate crystals in and on the + & - plates of the battery that are difficult, if not impossible, to reconvert to active material.
* Sulfation happens most at below 100% state of charge. Keeping your batteries as full as you can, as often as you can, will help minimize the formation of lead sulfate.
* It begins as soft lead sulfate, and if charged regularly, it can be reconverted to active material thus preventing the damaging hard lead sulfate from forming.
* If left at states of charge below 100%, as happens with mooring sailed or cruised boats, charged only via an alternator, the sulfate crystals can harden, die (become non-active) and adhere into and onto the plates. This basically acts as an insulation layer limiting current from properly flowing into and out of the battery.
How do I know if my batteries are sulfated?
* Charging current may never drop below 2% of battery capacity in the time it should take for the battery to become fully charged.
* When batteries should be "full" they are still warm or hot to the touch.
* SG is low in all cells and they had been "on-charge" for a long while.
* When your batteries are known to be severely discharged, like 50% discharged, and your charging voltage rises to absorption level "quickly". When battery voltage rises quickly on a deeply depleted bank this is a sure sign of sulfation.
* If state of charge voltage readings and SG readings do not agree, after resting.
* If the absorption voltage is correct 14.4-14.6 roughly, and temp compensated, and the batteries are rapidly boiling to excess.
* Poor performance
* You look in the cells with a flashlight and can see a whitish fuzz adhered to the plates.
So what can equalization do for my batteries?
Below is an example of a Deka Dual Purpose Starting/Deep Cycle battery that had been used as a house bank battery. The battery was installed in July of 2007 and has a June 2007 date code. The battery had never been equalized and it's depth of discharges are unknown. It had been topped up with water and charged via an alternator and occasionally a shore charger. It was on a 25 foot boat with an outboard motor. This was a simple 1 hour 15.5V equalization with a current of 2.2A to 2.6A during the duration. It is my guess that if I perform a second equalization I can get that battery to test out at the manufacturers "spec" of 650 CCA.
These are the test certificates taken before a 1 hour controlled equalization, and after:
Some cautions around equalizing:
It is generally best to equalize one battery at a time, not the whole bank.
Fully charge the battery to full, then add distilled water, and recharge. Only after these steps is it safe to equalize. Do not add distilled water to a discharged battery only to a full one,unless the plates are exposed.
Do not leave batteries on an equalization charge unattended
Turn off ALL DC loads. Equalization voltages may be too high for some electronics and the loads can also interfere with the EQ voltage.
Wear safety goggles & gloves when working around batteries
DO NOT equalize GEL CELL or AGM batteries. The only known exception to this is Lifeline AGM's which you can equalize...
What is "Equalizing" or a "Conditioning Charge"?
Equalization - A low current, high voltage controlled over charge of the battery.
Equalization or conditioning charges can help to:
* Balance the individual cells of a battery so that the voltages in each cell are closer to equal and the specific gravity is also closer equal across all cells.
* Reverse or help to shed the formation of hard lead sulfate on the and in the battery plates.
* Eliminate stratification effects where the acid concentration is weak on top and more concentrated down low in the battery.
Sulfation = Cancer of the Battery
Once the cancer has begun it is only a matter of time before the banks demise.
Equalization = Chemotherapy:
While equalization can help it can lead to other damaging effects and should only be used when absolutely necessary. Equalization can lead to errosion of the positive and negative plates which also reduces battery life. It is best not to do it "automatically" or too often. Only equalize on an as needed basis and turn off any auto equalization functions, if you can..
When should I equalize?
* When specific gravity (SG) & open circuit voltage do not agree
* When SG across cells varies more than .030 (.050 difference is a bad battery)
* When an individual cell requires more or less water than the others
* When you notice capacity loss
* When your wet cell batteries have sat for 2+ months without a charge or 5+/- months for Lifeline AGM
* Do not over equalize
* Follow your manufacturers guide-lines for equalization
* Use a PROPER charger that has a dedicated equalization mode. This is CRITICAL. Cheap chargers and "equalization" are not like bread and butter they DO NOT go well together.
* Most good quality marine chargers will do a separate controlled equalization at 15.3 - 16.0 volts, and low current, around 1.5% to 3.5% of the battery capacity. Do not buy a charger that puts out a 16V non-adjustable equalization voltage if you have batteries that require a limit of 15.5V etc. etc.. When shopping for a charger look at the specs of your batteries and your charger.
* Many chargers, such as Xantrex, time out the equalization mode at 1 hour. Your batteries may require more equalization and this "time out" allows you to test SG/Voltage etc. and then re-equalize if necessary.
What is Sulfation?
Sulfation = The formation of hard lead sulfate crystals in and on the + & - plates of the battery that are difficult, if not impossible, to reconvert to active material.
* Sulfation happens most at below 100% state of charge. Keeping your batteries as full as you can, as often as you can, will help minimize the formation of lead sulfate.
* It begins as soft lead sulfate, and if charged regularly, it can be reconverted to active material thus preventing the damaging hard lead sulfate from forming.
* If left at states of charge below 100%, as happens with mooring sailed or cruised boats, charged only via an alternator, the sulfate crystals can harden, die (become non-active) and adhere into and onto the plates. This basically acts as an insulation layer limiting current from properly flowing into and out of the battery.
How do I know if my batteries are sulfated?
* Charging current may never drop below 2% of battery capacity in the time it should take for the battery to become fully charged.
* When batteries should be "full" they are still warm or hot to the touch.
* SG is low in all cells and they had been "on-charge" for a long while.
* When your batteries are known to be severely discharged, like 50% discharged, and your charging voltage rises to absorption level "quickly". When battery voltage rises quickly on a deeply depleted bank this is a sure sign of sulfation.
* If the absorption voltage is correct 14.4-14.6 roughly, and temp compensated, and the batteries are rapidly boiling to excess.
* Poor performance
* You look in the cells with a flashlight and can see a whitish fuzz adhered to the plates.
So what can equalization do for my batteries?
Below is an example of a Deka Dual Purpose Starting/Deep Cycle battery that had been used as a house bank battery. The battery was installed in July of 2007 and has a June 2007 date code. The battery had never been equalized and it's depth of discharges are unknown. It had been topped up with water and charged via an alternator and occasionally a shore charger. It was on a 25 foot boat with an outboard motor. This was a simple 1 hour 15.5V equalization with a current of 2.2A to 2.6A during the duration. It is my guess that if I perform a second equalization I can get that battery to test out at the manufacturers "spec" of 650 CCA.
These are the test certificates taken before a 1 hour controlled equalization, and after:
Some cautions around equalizing:
It is generally best to equalize one battery at a time, not the whole bank.
Fully charge the battery to full, then add distilled water, and recharge. Only after these steps is it safe to equalize. Do not add distilled water to a discharged battery only to a full one,unless the plates are exposed.
Do not leave batteries on an equalization charge unattended
Turn off ALL DC loads. Equalization voltages may be too high for some electronics and the loads can also interfere with the EQ voltage.
Wear safety goggles & gloves when working around batteries
DO NOT equalize GEL CELL or AGM batteries. The only known exception to this is Lifeline AGM's which you can equalize...
