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Trimetric battery monitor

November 05, 2012, 03:05:40 pm

Has anyone installed a Trimetric battery monitor in a U280 or any FT where the house batteries are not in an enclosed space but out "in the open"  behind the drive wheels? It looks to me to be quite a project. Not much space to install a shunt back there, and then there is the issue of everything out in the open. My tentative plans are to get a piece of phenolic to use as a mounting board for the shunt as well as a terminal board for the batteries. Involves a bit of rerouting of the wires which is doable, but there just is not a lot of usable space back there to mount the terminal board to the chassis. Ideas anyone?

Roland

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Re: Trimetric battery monitor

Reply #1 – November 05, 2012, 04:36:56 pm

I wouldn't worry about the shunt being in an exposed location.  The voltage across the shunt terminals is negligable, and it is connected to the negative battery terminal, so accidental shorts to ground are not a problem.

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Re: Trimetric battery monitor

Reply #2 – November 05, 2012, 07:17:09 pm

I have a Trimetic but my batteries are in a bay as well as shunt
John H

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Re: Trimetric battery monitor

Reply #3 – November 05, 2012, 09:39:52 pm

Roland,
I know exactly what your taking about.  I don't like the wiring connections back behind the rear wheels either.  I have on my "someday" project list to enclose all of those in a sealed electrical box with a hinged access door.  But you would want to put the battery isolator in a box because of all the heat it produces.  I don't have that problem because I got ride of the isolator and just use my boost switch manually when driving.  Oh, and yes I turned down the alternator voltage since there isn't a diode drop across it anymore.

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Re: Trimetric battery monitor

Reply #4 – November 05, 2012, 11:35:54 pm

Our Trimetric shunt is in the center bay on the DC power panel, but I did mount a shunt of the same size in the engine compartment to measure alternator current.  I used a standard square weather tight outlet box (plastic) with a blank cover and drilled holes for the cables.  Sealed all holes and the cover with silicone.  I think you could do the same thing for your Trimetric shunt.  And I do think it would be best to enclose it, since the voltage sensed across the shunt is very small, and it wouldn't take much corrosion to change the readings. 

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Re: Trimetric battery monitor

Reply #5 – November 06, 2012, 01:20:02 am

John putting the batteries in the open behind the wheels just doesn't make a lot of sense to me, makes me wonder what were they thinking. Just checking and maintaining the acid level is a chore. I have also thought of enclosing the batteries but haven't come up with a plan yet. I will replace these batteries with AGM's when the time comes. I do plan on enclosing the shunt assembly however as I believe as Dave pointed out that corrosion could affect the readings.

Roland

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