Trimetric settings – lessons learned

[BendOR]

This is posted here since it mostly applies to those using solar while boondocking, either short term or long term.

The Trimetric is intended to help maintain battery systems for nominal 12V to 48V systems, such as those found in RV’s or off grid homes—which are regularly charged and discharged and use “deep cycle” batteries. The “amps” or “watts” display measures the rate of energy going in or out of your batteries so you can check your charging systems, and also to see how much energy each of your appliances use to help you conserve energy. The “% Full” display will help you keep track of how charged or discharged your batteries are. The “volts” display will let you discover if your charger systems are charging to the proper voltage, neither too high or too low, which is important for maximizing your battery life—also when battery voltage gets too low you will know your battery is getting really close to being discharged. The “days since charged” display shows how recently the main battery (system) was fully charged, so if it hasn’t been charged recently you can perform extra charging if necessary to help maintain the capacity of your batteries.

I installed my Trimetric 2025RV last fall. At that time, I searched the ‘net to see what others had. I found very little. Therefore, I’ll document what I’ve learned. My focus will be to those that use solar as their primary means to charge their RV 12 volt battery system. This could be for a weekend or for the long term.

Using the 2025RV with only the factory defaults, the Trimetric will show amphours (AH) used and count back up to zero with AH replaced through charging. Upon a manual reset, the unit will report that the battery is fully charged no matter what the +- AH count was.

The Installer’s Instructions and User’s Instructions recommended Level 1 settings, a review:

Level L1- Basic level (P stands for program function)

Set P1 (charged setpoint voltage); 1-2% below absorb charging voltage. Default = 28.6v

Set P2 (charged setpoint amps); 2% of P3. Default = off.

Set P3 (battery system AH capacity); approximate AH of charge (or energy) your battery bank holds when fully charged. Usually expressed at the 20amp/hour discharge rate. Default = 400.

The meter will then be set up to measure volts, amps/watts, battery %full and AH from full. However, with all other settings at their factory default, this might result in a nightly (when the sun goes down) automatic reset when using only solar recharging. If voltage is above P1 AND amps are below P2 at the same time then there will be an automatic reset while metered AH are still negative. Example: P1=13.5v (13.8 x .98) and P2=4a (200 x .02), the controller is in bulk charging stage, the meter reads -50 AH (75% charged), a cloud passes over obstructing the sun, volts drop but momentarily stay above P1 and amps drop below P2. This will result in an automatic reset. 75% charged (-50 AH) now reports as 100% charged (0 AH down).
Note: An automatic reset can be to your advantage, changing a +AH report to 0 AH used. Meaning, your battery bank is charged more than it was prior to the last count down.

Level L2- Allows all of L1 functions and the observation of historical data.

Level L3 – Allows all of L1, L2 functions and additional programing.

For solar charging, P12 and P14 are a very important part of L3.

P12 - Automatic reset; the default is on. This should be turned off if only Level L1 and/or L2 are used (P7 must be in L3 to change on to off then reset to L1/L2). With P12 set to off, all resets must be manual.

P14 – Allows a minimum time to be set where filtered volts have to be greater than P1 AND filtered amps less than P2 throughout before an automatic reset is activated. Default = 0.0 hours. Filtered describes a 4.8 minute moving average.

My setpoints, observations, opinions and reasoning:

When is a battery bank considered fully charged so that a manual reset is done to start the AH tracking?

I’ll consider the battery bank fully charged after a hydrometer confirmation, a rare equalization, after a weekly overcharge/top charge, or after a 2 plus hour haul where the engine alternator charges the bank. This charge will be the new basis for the stay and a manual reset will be done. Note: This will also compensate for general temperatures and aging banks gradually loosing AH capacity.

When is a good time for an automatic reset?

I want the conditions for an automatic reset to be hard to achieve and not often. Generally, only when the late afternoon AH count is positive (charged above the AH capacity of the last reset).

Considering the answers to the 2 above questions -

P1: I don’t want it based on the absorb stage voltage. Potentially, there are still too many AH to be pumped into the bank after absorb. I want it based on the float voltage. Anywhere from 1/2 to 1 volt below what the Trimetric reads as the true float voltage that is getting to your battery bank.

P2: I want the float stage to be active for a while with amps decreasing gradually as the bank tops off. I like 1 amp.

P3: Go with your best guess as to the capacity of your bank.

P7: L3 of course. I want access to P12 and P14.

P12: I want automatic reset set to on.

P14: Greater than P1 volts, less than P2 amps consistently for P14 time = reset. 1 hour seems reasonable to abate the passing cloud or afternoon thunder storm. YMMV.

All the other available P settings except for P10 have no direct basis on daily charging. P10 (assumed charging efficiency factor) is above most people’s (and my) ability to measure and adjust meaningfully. Set them as you may.

[bobandshaz]

Great info Thank you for the work!!"

[okiejim]

Great information thank you. I am going to try out your settings to see what happens. I have two aging t-105 and have the trimetric set to their recommendations and I never see my ts-45 charge controller get to float, it stays in either bulk in the morning and pwm in the afternoon.

[BendOR]

Jim-

I seriously don't think changing your Trimetric settings will get your TS-45 to go into float. The Tri is only a monitor not a charger. It will give you a truer idea of voltage & amps going to the batts.

You might want to review the controller settings vs batt manufacture charging recommendations and maybe do an equalizing. How are your hydrometer readings? Maybe go higher in your absorb voltage & longer.

http://www.trojanbattery.com/pdf/TRJ...UsersGuide.pdf

[bukzin]

Originally Posted by BendOR

Jim-

I seriously don't think changing your Trimetric settings will get your TS-45 to go into float. The Tri is only a monitor not a charger. It will give you a truer idea of voltage & amps going to the batts.

You might want to review the controller settings vs batt manufacture charging recommendations and maybe do an equalizing. How are your hydrometer readings? Maybe go higher in your absorb voltage & longer.

http://www.trojanbattery.com/pdf/TRJ...UsersGuide.pdf

Good info.

Any updates over the last 6 months of using your system?

[BendOR]

Thanks for asking!
Version 3 is below. The biggest minor change is that I played with P10.

Trimetric settings – lessons learned version 3

The Trimetric is intended to help maintain battery systems for nominal 12V to 48V systems, such as those found in RV’s or off grid homes—which are regularly charged and discharged and use “deep cycle” batteries. The “amps” or “watts” display measures the rate of energy going in or out of your batteries so you can check your charging systems, and also to see how much energy each of your appliances use to help you conserve energy. The “% Full” display will help you keep track of how charged or discharged your batteries are, the state-of-charge (SOC). The “volts” display will let you discover if your charger systems are charging to the desired (recommended) voltage which is important for maximizing your battery life—also when battery voltage gets too low you will know your battery is getting really close to being discharged. The “days since charged” display shows how recently the main battery (system) was fully charged, so if it hasn’t been charged recently you can perform extra charging if necessary to help maintain the capacity of your batteries.

I installed my Trimetric 2025RV in the fall of 2013. At that time, I searched the ‘net to see what others had used as setpoints. I found very little. Therefore, I’ll document what I’ve learned. My focus will be to those that use solar as their primary means to charge their RV 12 volt battery system. This could be for a weekend or for weeks.

Using the 2025RV with only the factory defaults, the Trimetric will show amphours (AH) used and count back up to zero with AH replaced through charging.
*****
The Installer’s Instructions and User’s Instructions recommended Level 1 settings, a review:

Level L1- Basic level, default. Note: P stands for program function.

Set P1 (charged setpoint voltage); 1-2% below absorb charging voltage. Default = 28.6v

Set P2 (charged setpoint amps); 2% of P3. Default = off.

Set P3 (battery system AH capacity); approximate AH of charge (or energy) your battery bank holds when fully charged. Usually expressed as the 20 amps per hour discharge capacity. Default = 400.

The meter will then be set up to measure volts, amps/watts, battery %full and AH from full. However, with all other settings at their factory default, this might result in a nightly (when the sun goes down) automatic reset when using only solar recharging. If voltage is above P1 AND amps are below P2 at the same time then there will be an automatic reset while metered AH are still negative. Example: P1=13.5v (13.8 x .98) and P2=4a (200 x .02), the controller is in bulk charging stage, say the meter reads -50 AH (75% charged), a cloud passes over obstructing the sun, volts drop but momentarily stay above P1 and amps drop below P2. This will result in an automatic reset. 75% charged (-50 AH) now reports as 100% charged (0 AH down).

Note: An automatic reset can be to your advantage, changing a +AH report to 0 AH used. Meaning, your battery bank is charged more than it was prior to the last reset. Upon a manual reset, the unit will report the battery is fully charged no matter what the +- AH count was.
*****

Other options:

P7 (Operational level) Default L1.
Level L2- Allows all of L1 functions and the observation of historical data.

Level L3 – Allows all of L1, L2 functions and additional programing.
For solar charging, P10, P12 and P14 are a very important part of L3.

P10 - Assumed charging efficiency factor; range is 60-100, the default is 94%. The charging of the battery requires more energy than discharging due to electrical, chemical and heat losses. Therefore, 10 AH of charging will not fully compensate for 10 AH of discharge. Using the default factor, only 9.4 AH will be counted toward charging after 10 AH has passed through the shunt. Some recommend a setting of 88-92% others recommend 94-98% depending on type/make of battery and charging rate/method.

P12 - Automatic reset; the default is on. This should be turned off if only Level L1 and/or L2 are used (P7 must be in L3 to change on to off then reset to L1/L2). With P12 set to off, all resets must be manual.

P14 – Allows a minimum time to be set where filtered volts have to be greater than P1 AND filtered amps less than P2 throughout before an automatic reset is activated. Range is 0-5, default = 0.0 hours. Filtered describes a 4.8 minute moving average.
*****

Observations, opinions, reasoning and my setpoints:

When is a battery bank considered fully charged so that a manual reset is done to start the AH tracking?

I’ll consider the battery bank fully charged after a hydrometer confirmation, a rare equalization, after a weekly overcharge/top charge, or after a 2 plus hour haul where the engine alternator charges the bank. This charge will be the new basis for the stay and a manual reset will be done.
Note: This will also compensate for general temperatures and aging banks gradually loosing AH capacity.

When is a good time for an automatic reset?

I want the conditions for an automatic reset to be hard to achieve and not often. Generally, only when a late afternoon AH count is positive (charged above the AH capacity of the last reset).

Considering the answers to the 2 above questions -

P1: I don’t want it based on the absorb stage voltage. Potentially, there are still too many AH to be pumped into the bank after absorb. I want it based on the float voltage. Anywhere from .1 to .4 volts below what the Trimetric reads as the true float voltage that is getting to your battery bank.

P2: I want the float stage to be active for a while with amps decreasing gradually as the bank tops off. I like 1 amp.

P3: Go with your best guess as to the capacity of your bank (start with manufacture’s data).

P7: L3 of course. I want access to P10, P12 and P14.

P10: I’ll take the middle ground, 92. If that is too high then I’m at least closer to reality than the default was. If it is too low then the replaced AH report is understated. When boondocking, an understated positive AH is not a bad thing.

P12: I want automatic reset set to on.

P14: Greater than P1 volts, less than P2 amps consistently for P14 time = reset. 1 hour seems reasonable to abate the passing cloud or afternoon thunder storm. YMMV.