CHARGING TERMS Bulk/Absorbsion/Float
Lots of confusion about these three terms. Let's simplify things a little. We have a TWO STAGE CHARGER. The main charger and a float. Not a three stage, that's a bunch of marketing hooey. The MA...
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The so-called "three-stage" converters are to blame for the terminology confusion. With those each "stage" is just a different level of voltage but they name them as though they were charging profile "stages".
Meanwhile the battery itself has the three "stages" in the profile Mex describes.
You have to pay close attention to context when people use the terms so you don't get mixed up what they are talking about.
Then you have Vector chargers like the VEC1093DBD, which are programmed to "trip" from constant amps as battery voltage passes through 13.9v. That is "Stage 1"
Amps now taper but voltage continues to rise all the way through "Stage 2" while amps continue to taper. So max voltage is reached just before they shut themselves down and say FUL (they claim to have a "Stage 3" at the end but if you blink you will miss it)
So they do not have a constant voltage for Absorption, but a controlled one from 13.9 to 14.8 while amps taper. This has the effect of slowing down the taper of the amps to a less steep curve and that keeps the time to get it done shorter.
You might ask why not just let it go to 14.8 and hold that while amps taper from there? Power requirement. The Vector is at max power at that 13.9/40a point = 556W. when it "trips" Later amps are down to say 35a with voltage now up to 14.2. 14.2x35 = 497 and so on
If it went to 14.8 before dropping from 40a, that would be 592w
Poor Mex would go even more crazy seeing that, where it is not in Bulk with voltage rising it is in Absorption with tapering amps.
Meanwhile the battery itself has the three "stages" in the profile Mex describes.
You have to pay close attention to context when people use the terms so you don't get mixed up what they are talking about.
Then you have Vector chargers like the VEC1093DBD, which are programmed to "trip" from constant amps as battery voltage passes through 13.9v. That is "Stage 1"
Amps now taper but voltage continues to rise all the way through "Stage 2" while amps continue to taper. So max voltage is reached just before they shut themselves down and say FUL (they claim to have a "Stage 3" at the end but if you blink you will miss it)
So they do not have a constant voltage for Absorption, but a controlled one from 13.9 to 14.8 while amps taper. This has the effect of slowing down the taper of the amps to a less steep curve and that keeps the time to get it done shorter.
You might ask why not just let it go to 14.8 and hold that while amps taper from there? Power requirement. The Vector is at max power at that 13.9/40a point = 556W. when it "trips" Later amps are down to say 35a with voltage now up to 14.2. 14.2x35 = 497 and so on
If it went to 14.8 before dropping from 40a, that would be 592w
Poor Mex would go even more crazy seeing that, where it is not in Bulk with voltage rising it is in Absorption with tapering amps.
