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Re: Faster Charging

PostPosted: Tue Jan 04, 2011 2:46 pm
by CMS
So I had an external regulator fail me a few years ago and converted back to the stock "dumb" regulator that I had never used, an adjustable Leece-Neville unit. I was amazed to find that my bank did not charge any faster or the alt supply any more amps to my bank from a depth of discharge of about 50% than it did with the "smart" regulator. I monitored this multiple times and switched back and forth between dumb and smart three times and plotted the charging but both regulators performed almost identically up to absorption voltage or until my banks were accepting less than 2% of the Ah rating.

I have since spent a good deal of time trying to figure out why I saw no difference with no good answers. As I understand it most of the regulators regulate voltage not amperage? Before the regulator hits the absorption set point, mine is14.4 volts, they are simply full fielding the alternator. So do both dumb and smart regulators do the same to the alternator, apply full field until the absorption voltage is reached? When they approach the absorption voltage they begin to limit the voltage to this level, in my case 14.4 volts on both the dumb and smart brand.

How will an Ample regulator change voltage limiting and feed my banks more amperage to charge faster? Can you please explain this to me in geek speak? Do your regulators hold a higher filed voltage at absorption voltage than a dumb one does? I have often heard dumb regulators referred to as "tapering" but my guess is that this comes from the auto field where start batteries quickly taper the current because they are already full. I can't seem to find any electronic circuitry in a dumb regulator that "tapers" it other than the batteries acceptance?

Can you please give me a detailed in-depth primer as to how your regulators actually charge faster than a dumb regulator set to the same absorption voltage so I can fully understand this. I am concerned with roughly 50% to 90% charging as I cruise and the solar tops off.

I am sold on the technology, especially temp sensing, but perhaps not on your competitors products. I know you really bashed the PS tests but also did not give much of an explanation explanation of how or why your regulators can charge faster. I don't see any trade secrets that would be given as there seem to be only a few things you can mess with to get more current into a battery, voltage or the field current but it seems the batteries will still decide how much they will take when up against acceptance?


Re: Faster Charging

PostPosted: Tue Jan 04, 2011 3:24 pm
by Coulomb
You're correct, during the bulk phase, the alternator is 'full fielded', by all regulators. But the term 'full fielded' is loosely defined as applying the maximum voltage that can be applied by the regulator. If you measure the voltage drop between B+ and field during the bulk cycle you'll find that an Ample Regulator drops the least voltage of any regulator. More voltage on the field means more Amps.

When is absorption voltage reached? At the setpoint, minus the resolution of the voltage measurement. To get a sharp cut off at the absorption cycle, the measurement needs to be made with high resolution; that is, resolution is a small percentage of battery voltage.

Measuring with high resolution comes with a price. Noise becomes an issue, and alternators generate plenty of it. Voltage drops between the regulator and system ground are now significant. To pay the price of higher resolution, Ample regulators separate digital ground from analog ground. You can see this on the wiring diagrams.

Another issue is the gain/bandwidth at which feedback is shifted enough to turn the system into an oscillator. The sampling rate on Ample regulators is higher than others, which can be seen by measuring response time to load changes on the system. Run a heavy load for a while and monitor a full battery with an oscilloscope when the load is turn off. The Ample regulator will recover much faster.

Fast recovery also comes at a price. This time it's buried in the microcomputer code.

That's about as geek as you're going to get.