Instruction Manual

26
P31: RelayOff: 28.8V, Batt%=80.
In case of disagreement between the voltage setting and BATT%FULL setting the voltage setting will
govern. .
P32-Batt1 charged criteria.
This tells the PentaMetric when the battery system measured by “volts1” and “amps1” is to be
declared “charged”. When this occurs, the “days since charged” display (AD24 or AD25) will be reset
to zero. Also, if the “battery capacity” (program numbers P14 or P15) are set to a “non zero” capacity,
the “Battery % full” display (AD22 or AD23) will be reset to “100% and the “amp hour” display (AD13-
AD14) will be reset to 0. These “charged criteria” must be set correctly to get meaningful data from the
“battery efficiency” measurements, (described in section 6.C.3.)
As a battery system becomes more fully charged its voltage rises, and eventually the charging current
drops. You may specify a voltage and a current (amps) that define when the battery is “charged”.
The PentaMetric considers the battery to be “charged” when the (filtered) Battery voltage (AD3)
equals or exceeds
the “voltage” setpoint entered here, and the charging amps (filtered Amps1, AD10)
current is LESS
than the amps value entered. Refer to section 7B for more details, and for
suggestions for actual values to be entered.
P33: Batt2 charged criteria. Same as P32 except for battery system 2.
P34-P35: Battery efficiency factor and Battery self discharge current.
Refer to section 7 for more information on programming this: How the PentaMetric keeps track of
battery “state of charge”. The purpose of both of these parameters is to compensate for the “self
discharge” current of the battery. If you don’t compensate for battery self discharge, the “battery % full”
values could be too optimistic. Section 7 describes in more detail the reason for “battery efficiency
factor” and “self discharge current” settings. A “bottom line” conclusion is that in most cases you will
want to use either
“battery efficiency factor or “self discharge current”, but not both simultaneously.
The “classic” method is to use only battery efficiency factor. A typical setting for “battery efficiency
factor” (used in the TriMetric) for a lead acid battery system is 94%--in which case you would turn off
the “self discharge” compensation by setting P35 to 0.00. This generally results in a slightly
pessimistic (low) reading for Battery % full, which is usually more desirable than having the reading too
optimistic. Incidentally, you turn off
the “efficiency factor” setting by programming it to 100%.
The use of a “self discharge” compensation current is new--so it is not yet known if this method may be more reliable
than the “classic” method of using an “efficiency factor” compensation. If you use “self discharge” compensation, the
value will typically depend on the capacity of the lead acid battery system. A “typical” value would be to divide the
capacity of the battery system (in amp hours) by 500 and put this value of “amps” in P35. (This is now a pretty wild
guess. More research is needed.) Then set the “efficiency factor”, P34, to 100%, so that both methods are not being
used simultaneously.
The values that are computed by the “battery efficiency logged data”(section 6.C.3) could be helpful in
determining a suitable value for these parameters.
Incidentally, it is possible to compensate with both “efficiency factor” (P34) and “self discharge current”
(P35). However we don’t yet recommend this yet. The logic for doing this might be to program the
“battery efficiency” for the amount of overcharge at the end of cycle, and program the “self discharge
current” for the actual “self discharge” current expected.
P36: Equalize interval.
This is used to define the “alarm time” for how many days should elapse between battery
equalizations. It is only applicable when the “time to equalize” alarm is activated. See section 6.E.5;
for more information. Enter the time in days desired between equalization reminders. If two battery
banks are being monitored, the same number applies to both banks.
P37: Maximum Charge interval.
This is used to define the “alarm time” for the maximum number of days which should elapse between
times that the battery is detected as “fully charged”. See section 6.E.4 Time to recharge battery for
more information. Enter the maximum time in days desired between a full charge. If two battery banks
are being monitored, the same number applies to both banks.