TM-2030 Technical Manual

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would cost twice as much to replace. (Of course you’d get more days of autonomy.) But in a vehicle it would
add extra weight. This measurement is a way of getting quantitative data on these kinds of questions.
H2-H6: Battery Charge Cycle Data provide answers to these system questions for the last five
charge/discharge cycles: A discharge/charge cycle begins at the time the battery is “fully charged” and ends at the
next “full charge”—a precise definition is given in section 6.2: How the TriMetric keeps track of battery % full.
H2 and H3: Did too many days go between full charges?
H4: System efficiency: Is a reasonable percent of the total charging energy being recovered during
each discharge(80-97%)—not too much or too little?
H5: How deeply are the batteries being discharged?
H6: How low does the battery voltage go?
More detail about what H2-H6 can tell you:
H2.1 through H2.5: (somewhat redundant information to H3) How many hours ago that the cycle in
question ended (H2.1 most recent cycle. H2.5 oldest cycle data).
H3.1 through H3.5: Length of the cycle in question, in hours. This shows how much time goes by between full
battery charges. Frequent charging helps keep them from permanently losing capacity. If solar charging is
used, and the days are sunny, they should charge nearly every day. If times are too long, say over 4 or 5 days
(96-120 hours) in a system that is being significantly discharged every day batteries may not being charged
sufficiently to maintain their capacity—although this could be OK if they are hardly used and mainly on float.
Long times could also mean either that the charger “absorb voltage” or “absorb time” is set wrong, or
that the “charged” setpoints in the TM-2030 programs P1 and P2 may be set incorrectly so that the
charging system cannot reasonably reach them. Then refer to data in H7-H9 (below) to show why.
H4.1 through H4.5: Total charge efficiency over each cycle (records total discharge divided by total charge)
which shows how efficiently the batteries are storing energy for that cycle—which from a theoretical system
efficiency standpoint would be ideal if 100%--but for a real system will be less. If this number is
consistently over 100% that means that the wiring to the shunt is incorrect, (batteries cannot be more than
100% efficient!)—possibly a charging source (possibly solar controller, or chassis ground?) connected to the
negative post of the battery instead of on the load side of the shunt, so the meter is not measuring it. If
unreasonably low, say below 70%, that may also indicate a miswiring—in this case a load that is connected
to the negative post of the battery. Or perhaps the batteries are old and inefficient. Or the charger could be
overcharging the batteries (which could also be damaging batteries—but this may not be significant if batteries
have been recently very lightly used—see “rPC” in section 2.1 page 4). For liquid electrolyte batteries an
average number between 80 and 90 is reasonable. If a higher average, the batteries are getting less than
10% overcharge, which is usually less than optimal for liquid electrolyte batteries. For AGM batteries ideal
could be 92-96% as they do not need as much overcharge. Another cause of an occasional high
percentage is that the temperature has gone down significantly between one full charge and the next. This can
cause the “charge setpoints” to be achieved with a lower state of charge than before—so less energy was able
to be charged. Similarly, an occasional low percentage could result if the temperature has risen at the
batteries, because when warmer they can accept more charge than before when cooler, which will reduce the
apparent efficiency value.
There should be some consistency in the readings. Although the values should ordinarily be less than 100%, as
said they can occasionally be greater than 100% when the temperature of your batteries drops as explained
above. If readings are wildly inconsistent it could be a wiring error, with a source or load that is connected to
the negative side of the battery, (a frequent installer mistake!) instead of on the load side of the shunt. (See
Figure 1 of TM2030 Installation instruction.)
H5.1-through H5.5: Minimum Battery % full during each cycle. This is another check to see how much
usage the batteries are getting, that they are not being run too low between charges.
H6.1 through H6.5: Minimum voltage during each cycle. This can show if the battery voltage is too low
before being recharged. Going below 11.5V or so (12V system) would indicate batteries are nearing their low
limit.
H7, H8, H9 check if proper charging is taking place. Charging data for each of the last 5
days: H7:Maximum charging volts. H8:Minimum charging Amps. H9:Maximum overcharge percentage