JHZR2
Staff member
Originally Posted By: ImpactBattery
Originally Posted By: JHZR2
Originally Posted By: 3311
Doesn't matter if the AGM, Gel or Flooded. The recharging process is the same.
Now if this is a trickle charger with a fancy name, that would work well, as others have said. Trickle charging, if you have the time is better because can avoid damaging a battery over gassing caused by high voltage and heat.
The process (e.g. CC/CV) may be the same, but the max charge voltage anf float voltages differ between gel, flooded and AGM, with the voltage increasing respectively.
Recombination kinetics generally occur at a rate to sufficiently allow C/3 charging. For a 60Ah battery, that means 20A. On bigger batteries like 49, 94, etc., 8A is roughly C/10. So generally most commonly available battery chargers will not create a thermal issue. There is a TON of thermal mass. Ambient will do more for degrading batteries.
On occasion, the high voltage is beneficial for equalization and for removal of sulfate. The means of removing sulfate is by presence of a high voltage charge, which causes gassing, which is why it is not desirable. The desulfation processes give a higher voltage for a short amount of time in a cyclic basis, so the time averaged gas generation is low enough to allow recombination.
To me, the most important thing is temperature compensation, as the voltage range in an area like the NE where we have four solid seasons is over 1.5V depending upon ambient temperature. Most cheap junior and HF type chargers dont temperature compensate. So they overcharge above roughly 75F, and undercharge below, like in the winter when it is more important. The lower the SOC, the higher the freezing point of the electrolyte. It doesnt take much to get the freezing point into the 20-27F range...
You are obviously a smart guy, but I am curious as to why you think the presence of a high voltage charge is the only way to remove sulfate crystals? High voltage charges can actually mess with vehicle electronics, harm batteries if not compensated for and was the basic method used in the 50's (yes the delivery method has been adjusted). Frequency pulsing dissolves the crystals and causes no excessive heat. I have yet to see an Xtreme charger over charge any battery. The microprocessor inside does all the work and since voltage never spikes above 14.8V and the unit continually tests the battery it cannot overcharge a battery.
The Battery Minder desulphating chargers that use both frequency based pulsing and voltage pulsing require a temperature compensation control (i.e. model BM12248) because they can overcharge based on ambient temperatures. That is solely due to the voltage spikes that average 18-22V, but I have been told can reach into the 40V range. These chargers work pretty good and would be #2 on my list behind PulseTech chargers. [We do not even consider CTEK a desulphating charger. Several years ago we pointed out our findings to them and they purchased some of the competition’s chargers to compare results…a couple months later we got the cold shoulder and the president of the company never replied to us again. We were hoping they would prove us wrong and send a detail comparison chart, but I guess the lack thereof indicates they did not stand up well to the head to head competition.]
I am interested in your comments of seeing 18-22V or 40V. I have not seen this, I have seen excursions in the 14-15V range, fluctuating, when under float, which is roughly 13.4V. Maybe the voltage spikes are higher and the sampling rate on my Fluke doesnt show it, but Ive not seen it.
Sulfate can be dissolved in the 2.5-2.66V per cell range. That is the 15-16V range. There is no basis I know of to justify 18, 22 or 40V. All it would do is instantly electrolyze some water if the current was high enough, or else bunch current and create a localized concentration overpotential someplace.
I agree if a charger is putting voltages like that out, there is a problem. Ive just not seen it...
Originally Posted By: JHZR2
Originally Posted By: 3311
Doesn't matter if the AGM, Gel or Flooded. The recharging process is the same.
Now if this is a trickle charger with a fancy name, that would work well, as others have said. Trickle charging, if you have the time is better because can avoid damaging a battery over gassing caused by high voltage and heat.
The process (e.g. CC/CV) may be the same, but the max charge voltage anf float voltages differ between gel, flooded and AGM, with the voltage increasing respectively.
Recombination kinetics generally occur at a rate to sufficiently allow C/3 charging. For a 60Ah battery, that means 20A. On bigger batteries like 49, 94, etc., 8A is roughly C/10. So generally most commonly available battery chargers will not create a thermal issue. There is a TON of thermal mass. Ambient will do more for degrading batteries.
On occasion, the high voltage is beneficial for equalization and for removal of sulfate. The means of removing sulfate is by presence of a high voltage charge, which causes gassing, which is why it is not desirable. The desulfation processes give a higher voltage for a short amount of time in a cyclic basis, so the time averaged gas generation is low enough to allow recombination.
To me, the most important thing is temperature compensation, as the voltage range in an area like the NE where we have four solid seasons is over 1.5V depending upon ambient temperature. Most cheap junior and HF type chargers dont temperature compensate. So they overcharge above roughly 75F, and undercharge below, like in the winter when it is more important. The lower the SOC, the higher the freezing point of the electrolyte. It doesnt take much to get the freezing point into the 20-27F range...
You are obviously a smart guy, but I am curious as to why you think the presence of a high voltage charge is the only way to remove sulfate crystals? High voltage charges can actually mess with vehicle electronics, harm batteries if not compensated for and was the basic method used in the 50's (yes the delivery method has been adjusted). Frequency pulsing dissolves the crystals and causes no excessive heat. I have yet to see an Xtreme charger over charge any battery. The microprocessor inside does all the work and since voltage never spikes above 14.8V and the unit continually tests the battery it cannot overcharge a battery.
The Battery Minder desulphating chargers that use both frequency based pulsing and voltage pulsing require a temperature compensation control (i.e. model BM12248) because they can overcharge based on ambient temperatures. That is solely due to the voltage spikes that average 18-22V, but I have been told can reach into the 40V range. These chargers work pretty good and would be #2 on my list behind PulseTech chargers. [We do not even consider CTEK a desulphating charger. Several years ago we pointed out our findings to them and they purchased some of the competition’s chargers to compare results…a couple months later we got the cold shoulder and the president of the company never replied to us again. We were hoping they would prove us wrong and send a detail comparison chart, but I guess the lack thereof indicates they did not stand up well to the head to head competition.]
I am interested in your comments of seeing 18-22V or 40V. I have not seen this, I have seen excursions in the 14-15V range, fluctuating, when under float, which is roughly 13.4V. Maybe the voltage spikes are higher and the sampling rate on my Fluke doesnt show it, but Ive not seen it.
Sulfate can be dissolved in the 2.5-2.66V per cell range. That is the 15-16V range. There is no basis I know of to justify 18, 22 or 40V. All it would do is instantly electrolyze some water if the current was high enough, or else bunch current and create a localized concentration overpotential someplace.
I agree if a charger is putting voltages like that out, there is a problem. Ive just not seen it...