What is the difference between a ferroresonant battery charger and any other type of battery charger?
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Ferroresonant
Batteries are fickle things and really need a three or four stage charger. I studied the Dytek ferroresonant charger which was original fit on my H376 and realised that all it did was to supply the battery with current which was stabilised against mains input voltage variations. Such variations may be common in marinas, particularly if the marina is not wired according to national codes of practice. So my Dytek is only a TAPER CHARGER and not at all suited to rapid recharging or complete charging to 100% of capacity as the proper multi-stage chargers do. I bought a Heart Interface charger/inverter and (now Zantrex)now only use the Dytek in the garage at home.
Batteries are fickle things and really need a three or four stage charger. I studied the Dytek ferroresonant charger which was original fit on my H376 and realised that all it did was to supply the battery with current which was stabilised against mains input voltage variations. Such variations may be common in marinas, particularly if the marina is not wired according to national codes of practice. So my Dytek is only a TAPER CHARGER and not at all suited to rapid recharging or complete charging to 100% of capacity as the proper multi-stage chargers do. I bought a Heart Interface charger/inverter and (now Zantrex)now only use the Dytek in the garage at home.
Go Chargers!
Sorry, got carried away there. *666 Ferroresonant Chargers use the battery charger transformer to help control charging current. This enables the manufacturer to save money on the charge control circuitry inside. They were a good idea for their time, before the modern family of integrated circuits and high power FETs were designed into charge controllers. The way they worked was the design had a limiting voltage and current. When putting out a lot of current (as into a discharged battery) the transformer (and a series resistor) dropped the output voltage, which controlled how much current went into the battery. As the battery state of charge increased, so did the voltage, and the currrent from the transformer decreased. So far, so good. Where they go wrong is once the battery reaches about 90% charge, extra electric current going into the battery is wasted as heat, and starts breaking down the battery water into oxygen and hydrogen. Usually the ferroresonant charger design didn't taper current off enough to keep this from happening. And when the battery was fully charged, often the charger had too high a float voltage, one that didn't cut off the current, instead kept heating the battery and causing the water to disassociate (gassing, making hydrogen and O2). This caused a condition called sulfation as the liquid dropped, and death to the battery. So enter the modern step charger, it uses electronics to go through the 3 main stages of charge and maintenance 0-90, 90-100% and float. The high end charger also measures the cell voltage and temperature and controls the rate of charge through that. Sometimes there is a fourth stage, called equalizing, where a deliberate overcharge is put on the battery. This is used because, if not moved or shaken, the battery acid will settle out according to is specific gravity, with water at the top and the acid at the bottom. This is bad because only that plate area in the acid will store and release charge. So a high current that causes gassing is used to "stir up" the acid/water mixture for a couple of hours. In a sailboat that rocks back and forth a bit, and thumps around, (IMHO) this fourth stage probably isn't really necessary.
Sorry, got carried away there. *666 Ferroresonant Chargers use the battery charger transformer to help control charging current. This enables the manufacturer to save money on the charge control circuitry inside. They were a good idea for their time, before the modern family of integrated circuits and high power FETs were designed into charge controllers. The way they worked was the design had a limiting voltage and current. When putting out a lot of current (as into a discharged battery) the transformer (and a series resistor) dropped the output voltage, which controlled how much current went into the battery. As the battery state of charge increased, so did the voltage, and the currrent from the transformer decreased. So far, so good. Where they go wrong is once the battery reaches about 90% charge, extra electric current going into the battery is wasted as heat, and starts breaking down the battery water into oxygen and hydrogen. Usually the ferroresonant charger design didn't taper current off enough to keep this from happening. And when the battery was fully charged, often the charger had too high a float voltage, one that didn't cut off the current, instead kept heating the battery and causing the water to disassociate (gassing, making hydrogen and O2). This caused a condition called sulfation as the liquid dropped, and death to the battery. So enter the modern step charger, it uses electronics to go through the 3 main stages of charge and maintenance 0-90, 90-100% and float. The high end charger also measures the cell voltage and temperature and controls the rate of charge through that. Sometimes there is a fourth stage, called equalizing, where a deliberate overcharge is put on the battery. This is used because, if not moved or shaken, the battery acid will settle out according to is specific gravity, with water at the top and the acid at the bottom. This is bad because only that plate area in the acid will store and release charge. So a high current that causes gassing is used to "stir up" the acid/water mixture for a couple of hours. In a sailboat that rocks back and forth a bit, and thumps around, (IMHO) this fourth stage probably isn't really necessary.
Try this reference
www.amplepower.com Download their Ample Power Primer. Equalization is not a fourth stage of charging, it is a completely separate regimen that must be continually kept under observation. It does, however, perform the task noted above. Stu
www.amplepower.com Download their Ample Power Primer. Equalization is not a fourth stage of charging, it is a completely separate regimen that must be continually kept under observation. It does, however, perform the task noted above. Stu
A fero-resonate charger is:
It is just an iron transformer that is constructed to resonate at 60 Hz. It improves the effecency if your windings and iron core are 60 Hz resonate to mach the 60 Hz AC input power. Most battery chargers are in fact fero-resonate. What you realy have to make sure of is that the two sets of windings are not electricly connected. If they are lots of bad rusty stuff starts to occur. Most good marine charger are of this type. Auto chargers almost never have the windings seperated.
It is just an iron transformer that is constructed to resonate at 60 Hz. It improves the effecency if your windings and iron core are 60 Hz resonate to mach the 60 Hz AC input power. Most battery chargers are in fact fero-resonate. What you realy have to make sure of is that the two sets of windings are not electricly connected. If they are lots of bad rusty stuff starts to occur. Most good marine charger are of this type. Auto chargers almost never have the windings seperated.
Not quite it, Bill
Most modern battery chargers are switching types not ferroresonant. The ferroresonant charger is just a design which regulates the charging voltage magnetically instead of electronically. You are right about not connecting the primary and secondary windings, though.
Most modern battery chargers are switching types not ferroresonant. The ferroresonant charger is just a design which regulates the charging voltage magnetically instead of electronically. You are right about not connecting the primary and secondary windings, though.
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