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Rbertalotto's avatar
Rbertalotto
Explorer
Aug 04, 2013

Solar Panel Charge Issues..Trimetric 2025RV....HELP!

I thought this solar stuff would be easy........NOT!

I have a 120w Solar Cynergy Polycrystalline solar panel on the roof of my TC.....7' of #10 wire to the controller....18" of #10 wire to the shunt....12" #10 wire to the battery

I have one brand new 95AH Deep Cycle, Walmart (Johnson Controls) 12V battery....

I have a Phocos 20A controller....

My TC has a Centurion 3000 power converter , 1998 vintage...

I have a Trimetric 2025RV with a 500 Shunt....
Current Readings:
Volts ... 13.2
Amps .... -00.3
Percent Full... - - -

Settings:
P1 ...14.3
P2 ...02.
P3 ...090.
P4 ...A
P5 ...OFF
P6 ...OFF
P7 ...L1



My battery will only get to 13.2V and there it stays.

I have used a SEARS smart battery charger hooked up to it for a couple of days...13.2V..no more
http://www.sears.com/diehard-platinum-microprocessor-controlled-battery-charger-engine-starter/p-02871227000P?prdNo=11&blockNo=11&blockType=G11

I've left the Centurion 3000 on for days...Battery gets to 12.9 on a digital VOM and no higher

The solar panel is putting out 19- 27V over the course of the day (The camper is parked in a partially shaded area when not being used)

The Phocos is outputting only 12.8V no matter the output of the panel.

I have a feeling the Phocos is garbage.....Just a hunch. I want to replace it with a Morningstar Sunsaver 20A PWM

I have a feeling the SEARS charger is rubbish. I've ordered the Black and Decker VEC1093DBD as it is spoken of extremely highly on this and other forums.

I'm not sure I have the Trimetric set properly. ??? Why is "% Full" still showing three dashes?

What is the best way to monitor the solar panel output....Simple volt meter or a clamp on amp meter? When I park for best sun exposure, does it matter whether I'm monitoring Volts or Amps?

Looking at my system, how come my battery won't come up to 14+ volts as I see referenced in many posts and articles here on the internet.

Any help is greatly appreciated.

Thanks!

11 Replies

  • BFL13's avatar
    BFL13
    Explorer II
    Aug 05, 2013
    Was just talking with an old time battery guy who said some batteries they had trouble with had what they called a "hole" in it, where no matter what you did it would not go above 13.5 volts, eg. It would heat up real good if you kept trying though. I think he said sometimes they would jolt it past there with an 18 volt shot.

    He said some had a "gap" instead of a "hole." These would work fine with a 20amp draw but not be able to run a light bulb. It needed something big to jump the gap and then work ok. I think he said after they jumped the gap then they could reduce the draw and it would then run a light bulb. He had lots of stories as old-timers do. :)
  • BFL13's avatar
    BFL13
    Explorer II
    Aug 05, 2013
    OP I can't tell from here what is what. You might be going over and over something that just needs a new set of eyes on it, and bingo.

    In our rig the only #10 used was a short length of each for the converter to DC dist panel. The rest was all #6 and #8. Anything I do in addition, near the battery gets #4.

    But that isn't your problem with not getting past 13.2. needs a new set of eyes.
  • Rbertalotto's avatar
    Rbertalotto
    Explorer
    Aug 05, 2013
    The installation manual says to use the same size wire or "larger" than the largest wire connected to the battery.

    The largest wire to the battery is #10.....In fact, ALL wires to ground and + are #10.....But it makes sense that the wire should be as large as the "total" of all the wires. There were four #10 wires connected to the negative terminal of the battery. I would think a #4 would compensate for these wires. I'll change that tomorrow.

    But the single positive wire that goes to the Centurion converter is only a #10...This wire is only 18" long as the converter sits directly over the battery.

    Thanks again!

    Will this make a difference? Or do I need the #4 simply for the shunt operation.
  • BFL13's avatar
    BFL13
    Explorer II
    Aug 05, 2013
    The shunt is part of the battery wiring and needs to be connected to the neg post with at least #4 wire since it carries the total amps of everything on the outboard end of the shunt. I use a store-bought short piece of "starter cable" that has the two ring terminal lugs already on it for that connection.

    In the OP you seem to be mixing up your units AH, volts? Hard to tell what the situation is. I suspect the equipment you have would work, but there is some kind of operator error somewhere. Can you ask another RVer at a campground who seems to have a good set-up to look at yours?
  • Rbertalotto's avatar
    Rbertalotto
    Explorer
    Aug 05, 2013
    I just went out and "tricked" the Trimetric to be sure it was working correctly. I changed the P1 reading to 13V instead of the 14.3 it was set at. The charger is outputting 13.2 volts.

    The Trimetric then started blinking the "Charging" light as now it was seeing more watts than what it was set to. So this is working fine.

    Then I went to "% Full" and it now shows 100% instead of - - -. So now I know this working.

    But the issue remains that the battery should charge to 14.3+/- volts and I simply can't get it there even with Solar, Sears Charger and Centurion 3000 all operating together.

    But I guess if neither of these devices are outputting over 13.2V that is all the battery will charge to.....can't get something for nothing....Correct?

    So if the Phocos doesn't output above 13.2, it matters not how much sun the panel is getting and how many volts the panel is outputting, the controller will limit the charge to 13.2....Correct?
  • Rbertalotto's avatar
    Rbertalotto
    Explorer
    Aug 05, 2013

    When using the Trimetric to monitor solar, be sure to turn off the automatic AH reset, or it will keep going back to zero when amps go negative, especially as it gets dark. Instructions for programming that in the manual.


    Looked everywhere and can't seem to find where to turn off the AH reset....
  • pianotuna's avatar
    pianotuna
    Nomad III
    Aug 04, 2013
    HI BFL13,

    Let's ask the OP for the specifications from the "name plate" on his panel? If it is operating at 27 volts then MPPT make sense. If, on the other hand it is a 12 volt (17 volt) panel then a decent PWM makes sense.

    I know you hate watts but his amperage is going to be desperately low with PWM if voltage is 27 (about 4.4 amps). With MPPT that may more or less double to 8 amps.

    BFL13 wrote:
    PT, the guy has only one 120w panel--whyinhell would you tell him to get MPPT!!!!
  • Rbertalotto's avatar
    Rbertalotto
    Explorer
    Aug 04, 2013
    Thanks BFL... I'll check the AH reset.

    My Trimetric shows -00.3amps (negative) no matter how much energy I try to put back into the battery. I believe the -00.3amps is the propane and CO2 monitor/alarms as everything else is off.

    I've double and triple checked my wiring. It is as the manual states. The battery side of the shunt has one #10 wire to the NEG terminal of the battery. Everything else is hooked to the outboard side of the shunt.

    I use a four conductor, double twisted pair wire with the proper twists to the proper terminals on the side of the shunt.

    My concern is that no mater what I do I can't get the amps to go positive and the voltage stays as 13.2.

    The Phocos also came with a digital read out module (Phocos CMM) but I removed it when I installed the Trimetric. It never showed more than 1 amp no matter how much sun was on the panel.

    Is this more food for thought?
  • BFL13's avatar
    BFL13
    Explorer II
    Aug 04, 2013
    PT, the guy has only one 120w panel--whyinhell would you tell him to get MPPT!!!!
    -----------
    The Trimetric only reads what goes across the shunt, so be sure the neg output of the solar controller is on the outboard end of the shunt, not the battery neg post end of the shunt.

    Check to see you have the small wires on the shunt at the right ends iaw the Trimetric manual's diagrams.

    When using the Trimetric to monitor solar, be sure to turn off the automatic AH reset, or it will keep going back to zero when amps go negative, especially as it gets dark. Instructions for programming that in the manual.

    With everything in the rig across the Trimetric including solar, you have to derive what is the solar part. this is fairly easy once you know your usual day. eg, if solar is doing +10amps and you have a light on at -3a, then the Trimetric will show the net of +7 amps.

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