[RE-wrenches] Fwd: PENTAMETRIC

[Michael Welch]

 From Julie Haugh jfh at greenhousepc.com

>>Seems the benefit of using % charge would go out the window if your batteries were sulphated....just when you would need the voltage based/temp comp logic the most.  No experience with your proposal though.
>
>The PentaMetric has a feature that allows you to determine if the batteries are sulfated by comparing the state of charge and discharge voltage.  A healthy battery has a fairly linear decline in (temperature corrected) voltage under load.  The discharge voltage of a sulfated battery collapses in a very characteristic manner.  What the PentaMetric does is track voltage, load, and state of charge in an internal spreadsheet.  What you want to see is nice, smooth curves with no abrupt drops.  And the great thing about this feature is that it will tell you went a battery is sulfated, but not so badly that it is obvious.
>
>I forget the exact option, but the software that is included with the PentaMetric should allow you to download the spreadsheet that's in the PentaMetric's memory and look at the SOC / voltage data.
>
>As an aside, there are advantages and disadvantages to using SOC to control generator start and stop. The better solution is to use both temperature compensated voltage and state of charge.  Voltage protects against integration (rounding) errors in the SOC calculation, while SOC protects against discharging under low load when the voltage might remain higher than the low voltage start.
>--
>Julie Haugh
>Senior Design Engineer
>greenHouse Computers, LLC // jfh at greenhousepc.com // greenHousePC on
>Skype