Bogart Engineering TriMetric 2025 Battery System Monitor
Size : 4.5" x 4.75"
Designed for the interior of your RV
Manufacturer Part Number: TM-2025-RV
The TriMetric is used to monitor battery systems used in remote homes, RV’s or boats that have batteries that store solar, wind, or possibly generator powered chargers. They will help you maintain your batteries. The end cost, including the required shunt you will need to purchase separately, comes in under $200.
Please note that if you do not already have a shunt installed in your system, you will need to purchase one separately. This is not included with the product because some systems may already have a shunt installed.
The newer TM-2025’s have much in common, and also a few advantages over the older TM-2020, which we believe makes the TM-2025 a better choice now. There are also two choices of TM-2025, the TM-2025-RV and TM-2025-A, but there is no operational difference—they only differ in their size and the color of the front label. The TM2025 A is designed to fit an a “double gang” electrical box of appropriate size, and does not come with its own box. The TM-2025-RV is physically slightly narrower, and has its own box, with more muted color scheme designed to fit with the interior of an Recreational Vehicle.
All models are designed to monitor the following:
"Percent Full" ("State of charge") of your batteries, so you can see if you need to charge them more, or check that overall usage is less than your charging resources.
Volts of the batteries, for example to check that they are being charged at proper voltage.
Energy going in, or out of your batteries, measured in Amps or Watts, so you can see that your charging sources are charging properly, or how much current your loads are using.
How many days since the batteries were fully charged: to remind you to not wait too long between fully charging your batteries to maximize their life.
TM-2025 Advantages over TM-2020
The TM20205 is easier for you to program the necessary system parameters.
The TM2025 has some minimal data logging, which can be useful for a technician to diagnose some common setup or operational problems with battery systems.
The TM-2025 will operate with (nominal) battery systems from 12 to 48V.
- The TM-2020 will operate with 12 or 24 V systems, but requires the addition of the “TM-48VA” Adapter and lightning protection board when using it with 48V battery systems. This also provides lightning protection for the TM-2020.
The TM-2025 can also monitor the voltage only of a second battery, such as a starting battery, or possibly also the input voltage of a solar array (if less than 100 volts.)
The TM-2025 has a “simplified” level of operation suitable for most users, but can be configured for more flexibility (and complexity) where occasionally required.
(For the technically knowledgeable only): It has a serial data output of all the “real time” data—which could be used to access data for other control or output in, for example OEM applications.
The newer TM-2025 includes better lightning protection.
It is easier to view and enter programmed parameters.
It is about typically about $15 more than the TM-2020. For 48V systems it is less expensive than the TM-2020 because it does not require an extra 48 volt adapter.
Which shunt should I use with the TriMetric or PentaMetric?
For medium and larger systems most people use the 500A/50mV shunt. There are two things to consider when deciding which to use:
If you will be measuring current with the meter that is greater than 70 Amps (charging or discharging) then the 100A/100mV shunt is too small (it will overheat), and you should use the 500A/50mV shunt. For example, a 12 V battery system with an inverter over 800 watts could exceed this, and the 500A/50mV shunt should be used. The maximum current in Amps in this case is 800 divided by 12, which is 66 Amps.
If you will be measuring current with the meter that is less than 70 Amps, then you may use either a 500A/50mV shunt or 100A/100mV shunt. But the 100A/100mV shunt will allow you to see on the meter currents as low as 0.01 amps, whereas with the 500A/50mV shunt you will see currents only down to 0.1 amps. So with smaller systems you will be able to more accurately measure very low currents with this shunt
What is the differencer between TriMetric and PentaMetric?
The TriMetrics and PentaMetric are both designed to help you maintain batteries which are periodically charged and discharged such as are typically used for storing energy in solar or wind powered homes, RV’s or boats or (for the PentaMetric) remote offgrid commercial sites with batteries.
The TriMetric will be the choice for most battery systems in homes, RV’s and boats where the owner does not need the greater analysis capability that the PentaMetric has.
The PentaMetric has additional capability to do more extensive system analysis, and logging of system data, which can be controlled by a computer and emailed or even controlled and analyzed remotely. The PentaMetric may be appropriate for larger systems or for systems owned by technical users who are interested in more system detail, or systems which may be managed by installers that are not usually at the battery site, or unattended commercial installations.
Both monitors show you the following:
flow of energy in or out of the batteries (in amps or watts) so you can check your charging sources or electrical loads.
battery state of charge (i.e., how much energy is left in the batteries)
how recently since you fully charged the batteries, which is useful because lead acid batteries should not go too long between being fully charged.
How they keep track of "state of charge": They both determine the "state of charge" by keeping track of the amp hours flowing in and out of the batteries. This is a more accurate method than using only the battery voltage as some less expensive meters do.
The TriMetric battery monitor now comes in three variations: The TM-2020 has been made since 1999. The (two) newer TM2025-RV and TM2020-A models were introduced in 2009, and are very similar to the TM-2020, but have some improvements over the TM-2020 based on customers’ experience.
The two newer TM-2025’s are both identical to each other in function, but differ only in physical size and label colors. The TM-2025-RV has its own enclosure with more muted front panel colors. The TM-2025-A has a larger panel size and fits into a "double gang" electrical box, which is not included, but can more easily be flush mounted on a wall.
All require external shunts: Both TriMetric and PentaMetric measure the amps flowing in and out of the batteries by using an electrical shunt (or shunts) that are accessories which must be installed in series with the negative cable of the battery system. They cost about $30 each. There are two types depending on whether the maximum current flow (amps) charging or discharging is less or greater than about 70 amperes. More shunt info can be found in our application notes.
The PentaMetric is more complex and more expensive—but that does not mean that it is necessarily better for any application than the TriMetric. For many users the TriMetric is the better choice because it is less costly, and simpler to install and use.