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Bogart Engineering TM-2020 TriMetric Meter Battery Monitor

Bogart Engineering TM-2020 TriMetric Meter Battery Monitor
Bogart Engineering TM-2020 TriMetric Meter Battery Monitor
Item code Brand name Model number
BOGTM2020 Bogart Engineering TM-2020
You will need to purchase a shunt separately. 100 or 500 amp shunts are used most often.

Bogart EngineeringBogart Engineering
The TriMetric MODEL 2020
Battery Monitor

This Battery Monitor Measures:
Battery Volts, Amps, Amp-Hours, Battery Percent Full, and Five Other Data Functions

The TriMetric MODEL 2020 Battery Monitor
Size : 4.5 x 4.75 inches.
Shown in optional "double gang" box.

If your home, R/V or boat depends on batteries for electrical power, here's why a battery monitor should be part of your electrical system.

Helps save valuable energy by letting you see how much you're using
  • Use "amps" to educate users about how much energy different electrical loads draw.
  • Check that all loads are really off when you think they're off.
  • Check for "phantom loads"-small loads that steal power 24 hours per day.
  • Keep informed about how much energy you have left in your battery system.
  • Reduce generator use by knowing when you can efficiently shut it off because batteries are approaching full charge.
Provides information you need to protect your battery investment.
  • Know when to turn on your generator to avoid damage from over discharge.
  • Check that charging systems are charging to correct voltage for longest life.
  • Be reminded not to let batteries go too many days between a full charge.
Helps locate system problems when they occur.
  • Monitor solar arrays and inverter/chargers to be sure they are still charging at proper rates and voltage.
  • Find out if batteries are still holding energy properly.
  • Even if you're not an expert, a dealer or other knowledgeable person can more easily help you by phone to locate a problem if you have a monitor on your system.

Operation and Specifications for Trimetric 2020

"BATTERY PERCENT FULL" display shows how full the battery is by the most accurate method: measuring amp hours expressed as a percentage of a full battery.

AMP HOURS FROM FULL shows how much energy has been taken out of a full battery.

EASY TO UNDERSTAND FRONT PANEL AND CONTROLS All display and RESET functions are explained on panel. The six less used functions are easy to access, yet easy to ignore if not needed.

Battery Monitor

Make good battery care easier: This battery monitor shows when recharging should occur, or battery voltage gets too low. It's important to periodically fully charge lead acid batteries to keep them in good condition. Program the desired maximum number of days(1-60) between full chargings. Then, if the batteries exceed that time without being fully charged the BATTERY REMINDERS lamp will occasionally blink, and the display will flash "Ch. F", (as shown on the label) every 5 seconds to explain the reminder. Similarly, program in desired number of days (1-250) between battery equalizations and the TriMetric will remind you when to equalize. (When equalization is accomplished you'll need to reset the "days since equalized" data so it will remind you again the next time). Program in the desired value of "lowest battery voltage" and the lamp will flash when battery voltage falls below that voltage. You can disable any or all of these.


Push SELECT to cycle through these:
Battery Volts: Reads 8.0 - 35.0 volts accurate to ±.08 volt including "digit resolution" accuracy. An optional adapter extends this to 70 volts for 32 or 48V systems and delivers lightning protection too. Please see accessory section for additional information.

Battery Amps: Measures amps into and out of battery, accurate to ±1% ±1 least significant digit. Or the meter may be set up to measure only incoming amps from solar array or other energy source, or only load amps if desired. Resolution and maximum amps depends on choice of shunt. With the 100A/100mV shunt: measures 0.01 to 250 amps. With 500A/50mV shunt: measures from 0.1 to 1000 amps. Shunt type is programmable, so amps always display correctly. Speed of response one second time constant.

Battery Percent Full: This number is based on net-amp hour reading divided by the user programmable value of battery capacity. This is more reliable than other methods which do not use amp hours to compute battery energy content (for example less expensive monitors which rely only on battery voltage to estimate energy content). There is a (user programmable) choice of two ways to display this result: (1) an exact, literal reading from 0-100% in increments of 1%, or (2) a more "honest" display which shows in steps of 5%, and displays "FUL" when above 92%, and "LO" when below 27%. Although the meter amp hour measurement accuracy is ±1%, this option is intended to reflect the fact that the system accuracy in determining how much energy content in an actual battery system, (assuming the batteries are recharged fully at least every week) is more honestly stated as ±5%. The assumed BATTERY CAPACITY, upon which this display is based, can be programmed from 10-2550 amp hours, in increments of 10 amp hours.

Display Off: The display may be turned off (for lowest current draw of 16 ma.

Other Features

How the TriMetric Determines that Batteries are Charged: When the TriMetric senses that batteries are charged, it resets the "days since charged" display to 0.00 and (at user option) resets the "amp hours" to 0.00 and the "Battery % Full" to 100%. The TriMetric determines that the batteries are "charged" when the battery voltage rises above a user programmed "charged voltage" (adjustable from 10.0-35.0 volts within 0.1 volt) and the charging amps goes below a user programmable "charge current criteria" (adjustable from 1-100 amps within 1 amp). This condition must remain for 20 seconds.

User Selectable Efficiency Factor: Amp hours may be monitored without an "efficiency factor," meaning that the "charge" and "discharge" current for the "net amp hours" reading are both accumulated at exactly 100% rate. Or a "charge efficiency" factor may be manually set from 60% to 100% in 1% increments. This means that the discharging current will subtract from amp hours at 100% rate, where as the charging current accumulates at the lower specified rate, to approximate the "charge efficiency" of the battery. This compensates for the fact that you don't get quite as much charge out of a battery as you put in.

The Same Reliable, Proven Measurement Circuit: This TriMetric Battery Monitor circuit has proven accurate and reliable for over three years in production. All programmed information retained when meter unpowered.

Remote Locatable: Up to 55 feet with four #22 ga. wires. Up to 150 feet with #18 wire. Longer distances are possible with larger wire size.

Bright Display With Low Current Draw: Requires about 30mA with display on-about 16mA with display off.

Size: The battery monitor is designed to fit into a standard "double-gang" electrical box mounted 90 degrees from the usual position. See accessories section (on the back) for suitable enclosure. Panel size (inches): 41/2 x 43/4 x 13/4 deep.

Warranty: The Bogart Engineering warranty policy is to repair at no cost any of their products that develop a problem not due to customer misuse.

TM2020 Battery Monitor Operational Information:

Hold the SELECT button down for two seconds, release, then push SELECT again to cycle through these six functions. The data alternates with identifier letters which are shown on front label.

  1. Amp Hours From "Full": Shows actual "net" amp hours removed from the battery from ±0.01 to ±9,999 amp hours. A flashing decimal point reminds you to multiply the reading by 1000 when the amp hour number exceeds 999. May be manually set to 0, or automatically when the "charged" criteria are met. (See information below on "How TriMetric determines that batteries are charged"). It is also possible for this display to measure only total amp hours produced by an energy source, such as solar array, or only load amp hours, by wiring the shunt in the desired current path.
  2. How Many Days Ago Since Batteries Were Last Fully Charged: To prolong their life, lead-acid batteries shouldn't go too long between being fully charged. This display will show you how long since they last received a full charge-measures from 0.01 day to over 600 days. It's a timer that resets to 0.00 whenever batteries are fully charged (i.e. meets charged criteria as described below). If desired the "battery reminders" lamp will alert the user when this number exceeds a value programmable by user from 1 to 60 days. May also be manually reset with the "reset" button.
  3. How Many Days Ago Since The Battery Was Equalized: "Wet cell" lead acid batteries should be periodically given an overcharge, called "equalization," to maintain their capacity. This is typically done every month or two. It's easy to forget when they were last equalized-this timer will keep track for you. Reads from 0.01 day to over 600 days. You will need to reset this number manually whenever you equalize the batteries. In addition, if desired the "battery reminders" lamp will alert you when this number exceeds a user adjustable "maximum equalize time" from 1-250 days.
  4. Cumulative Battery Amp Hours: Records only discharging amp hours-displays to minus one million amp hours. (A flashing decimal point in the display tells you to multiply the reading by 1000). This function acts like an odometer in a car, to show how much total chemical change the battery has seen in its life. It's a "bottom line" number of total battery endurance and can be used to evaluate the life performance of the batteries and the care they've received at time of replacement of the battery set. This number stays in the TriMetric even if power is disconnected-in that case a maximum of the last 3.2 hours of data will be lost. When replacing the battery set the number to 0 by pushing "reset" button while this display is showing.
  5. Maximum Battery Volts: Useful to check that the charging sources are charging to the voltage recommended by battery manufacture for longest life. Pushing the "reset" button when displayed to reset this display to the present battery voltage.
  6. Minimum Battery Volts: Use this to check that batteries haven't been over discharged. Pushing the "reset" button when displayed to reset this display to the present battery voltage.


Bogart Engineering

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