Trimetric 2025RV initial settings
Oh wise one's in PWM and Trimetric’s: I’d like some advice on initial settings for a Trimetric 2025RV. Most of my camping is boondocking using solar with a 2K gen as backup. I’ve been upgrading my 1...
Forum Discussion
Trimetric settings – lessons learned
I installed my Trimetric 2025RV last fall. At that time, I searched the ‘net to see what others had for their settings and why. 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 backup to zero with AH replaced through charging. With solar charging only and no other overnight charging source, the unit may automatically reset to zero when the sun goes down. Upon reset, the unit will report that the battery is fully charged no matter what the +- AH count is. There may be no long term (more than a day) running total of AH used/recharged.
The Installer’s Instructions and User’s Instructions recommended Level 1 settings, a review:
Level L1- Basic level
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 too might result in a nightly 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 and the observation of historical data.
Level L3 – Allows all of L1, L2 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 rare equalization, after a daily/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 good 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 is above most people’s (and my) ability to measure and adjust meaningfully. Set them as you may.
BFL13 - I apologize for changing some of my numbers suggested in the past.
Flame away gents. 8>)
I installed my Trimetric 2025RV last fall. At that time, I searched the ‘net to see what others had for their settings and why. 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 backup to zero with AH replaced through charging. With solar charging only and no other overnight charging source, the unit may automatically reset to zero when the sun goes down. Upon reset, the unit will report that the battery is fully charged no matter what the +- AH count is. There may be no long term (more than a day) running total of AH used/recharged.
The Installer’s Instructions and User’s Instructions recommended Level 1 settings, a review:
Level L1- Basic level
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 too might result in a nightly 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 and the observation of historical data.
Level L3 – Allows all of L1, L2 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 rare equalization, after a daily/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 good 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 is above most people’s (and my) ability to measure and adjust meaningfully. Set them as you may.
BFL13 - I apologize for changing some of my numbers suggested in the past.
Flame away gents. 8>)
