Trimetric 2025 Reset

Dalama32

I have recently purchased a trimetric 2025. The issue I am having is that the unit will reset to 100% and the AH to 0 whenever the power is cycled. I was hoping that it would "remember" its last state, alas this does not seem to be the case. I was then hoping there was way to "set" either the % to a given value Or the AH but I can't seem to do this either. The reason I want to do this is I have to disconnect the unit from the battery bank for short periods of time. I know for example that when I disconnect it was at 80%. I would like to some how either have it remember that 80% or be able to set it back to 80% when power is restored. Is there any way of accomplishing this? Can it be powered by a different source than it is measuring?

Thanks

NorthGuy

Re: Trimetric 2025 Reset

Dalama32 wrote: »

I have recently purchased a trimetric 2025. The issue I am having is that the unit will reset to 100% and the AH to 0 whenever the power is cycled. I was hoping that it would "remember" its last state, alas this does not seem to be the case. I was then hoping there was way to "set" either the % to a given value Or the AH but I can't seem to do this either. The reason I want to do this is I have to disconnect the unit from the battery bank for short periods of time. I know for example that when I disconnect it was at 80%. I would like to some how either have it remember that 80% or be able to set it back to 80% when power is restored. Is there any way of accomplishing this? Can it be powered by a different source than it is measuring?

I think it's been a thread here recently about modifying try-metric for higher voltages that had instruction on how to power it with outside source, but I cannot find this thread.

BB.

Re: Trimetric 2025 Reset

From the Data Sheet:

Requires about 30 milliamps with display on—about16 milliamps with display

I was thinking of using a blocking diode to power the unit with the battery bank removed--But that is iffy too... You will lose ~0.2 to 1.0 volts through the diode (or several diodes, one to the main bank and a second to a backup battery.

Why remove the battery bank except for external charging/discharging? Which the meter then would know nothing about.

I could see installing a battery monitor with the removable battery pack (say everything on a pallet)... But it does sound a little strange.

Bogart Engineering (the mfg. of the -metric battery monitors) has done custom units for other mfg. (such as integrated battery monitor for Apollo controllers--I believe)--Perhaps you can discuss your application with them and see what they say.

-Bill

Dalama32

Re: Trimetric 2025 Reset

Okay, after a little experimentation, this is what I have done...

I will use a 8 x 1.2v NiMh back up battery pack and a 1n4004 diode which gives me a working voltage of about 8-10.5V (after 0.7V drop). This voltage ensures that my backup battery is always less than my main voltage so battery will only be used when main is disconnected. A couple of notes. The Trimetric will stay powered on until about 7V but its display will not display the correct voltage (always higher). It needs about 10.5V before it become accurate. The diode is connected to the B1 and the battery negative to the G1. One problem is that with no shunt connections the amp reading is incorrect and will throw my AH accumulation off. I created a dummy plug that connects SIG to G2 to eliminate this (well almost - reads 0.01A). Another annoyance is that with the display off, it will use less power but... the low battery alarm "wakes up" the display periodically which causes it to use more power. The lowest you can set the alarm to is 10V. Anyway, I tested and get just over 24h of battery time (8 eneloops).