Maretron DCM100 - Manual (Page 16)

DCM100 User’s Manual
Page 12 Revision 1.0
restated version of the equation, which allows you to calculate the time to totally discharge a
given battery at a given discharge current, follows:
ܶ ൌ ܴ ቀ
஼
ூோ
ቁ
௡
,
w
= the rated battery capacity in Amp-hours,
here
= the number of hours over which the rated battery capacity was calculated (usually 20),
ܥ
= the discharge current in Amperes,
ܴ
= the time to discharge the battery in hours, and
ܫ
ܶ
݊ = the Peukert constant for the battery (dimensionless).
The Peukert constant for an ideal battery is 1.0. For lead-acid batteries, the value of the
Peukert constant is in the range of 1.10 – 1.25.
The DCM100 takes the Peukert effect into account when calculating the state of charge of a
battery.
Please contact the manufacturer of your battery to obtain the Peukert’s constant for the battery
to which you are connecting the DCM100.
5 Synchronization
In order to keep state of charge readings as accurate as possible, the DCM100 must
periodically (once per month is recommended) be synchronized with the battery. This is done
by fully charging the battery. When the battery is at the “Fully Charged Voltage” and the
current flowing into the battery is below the “Fully Charged Current” threshold for more than
the “Fully Charged Time”, the DCM100 sets the state of charge of the battery 100% (see
Sections 2.5.4.7, 2.5.4.8, and 2.5.4.9 starting on page 7 for details).
5.1 Charge Efficiency Factor Calculation
The battery must first be discharged below the synchronization threshold state of charge. The
battery must then be fully charged.
At this point, if the “Charge Efficiency Factor” is set to “Auto”, the DCM100 re-calculates the
Charge Efficiency Factor based on the amount of energy which flowed into the battery during
the charging cycle. This new Charge Efficency Factor value is used for further charging
cycles. Alternatively, you may manually set the value of the “Charge Efficiency Factor” (see
Section 2.5.4.6 on page 7 for details).
6 Maintenance
Regular maintenance is important to ensure continued proper operation of the Maretron
DCM100. Perform the following tasks periodically: