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Author Topic: MorningStar TriStar MMPT-45 Overcharging  (Read 163 times)

Heli_av8tor

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MorningStar TriStar MMPT-45 Overcharging
« on: September 21, 2018, 02:02:11 PM »
My controller is set for Absorb = 14.7v and Float at 13.5v. (Switches 4-5-6 = on-off-on). The remote verifies this setting.

However, the controller routinely runs in Absorb mode in the morning running the battery voltage to 15.0 to 15.1 before switching to Float mode.
This voltage is reported both by the Morningstar remote and my Trimetric battery monitor. This is with minimal overnight battery draw and/or on shore power (Xantrex Freedom XC 2000).

Batteries: 2 - FullRiver DC260-12

Why would it be doing this and how do I correct it?

Thanks,
Tom
Tom & Theresa
2004 Pace Arrow 37C, Workhorse W22, 8.1 Vortec
2014 Honda CR-V Toad, Roadmaster -5 Base and tow bar
SMI Stay and Play Duo Brake system

AStravelers

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  • Part time travelers, 4-8 months each year.
Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #1 on: September 21, 2018, 05:30:44 PM »
You could contact Morningstar support.  It looks like you would have to go online and describe the problem and they will get back to you.  I didn't see a phone number listed in the support contact page.
Al & Sharon
2006 Winnebago Sightseer 29R
2009 Chevy Colorado 4X4

http://downtheroadaroundthebend.blogspot.com/

PJ Stough

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Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #2 on: September 21, 2018, 05:36:47 PM »
Mine will do the same when the weather is cooler, as I have mine set for 14.7 volts temperature corrected, and have seen as high as 15.3 volts when the outside temperature is down in the 40s or 30s.
PJ Stough   Iowa
2005 Winnebago Voyage 38J

Heli_av8tor

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Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #3 on: September 21, 2018, 08:42:41 PM »
Thanks Al and Paul.

My battery temperature was 55 this morning.

See you both in KOFA or Q this year?

Tom
Tom & Theresa
2004 Pace Arrow 37C, Workhorse W22, 8.1 Vortec
2014 Honda CR-V Toad, Roadmaster -5 Base and tow bar
SMI Stay and Play Duo Brake system

Kevin Means

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Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #4 on: September 22, 2018, 12:21:11 AM »
We have a different controller Tom, and unfortunately I'm not familiar with how to program Morningstar controllers. However, I would recommend that you keep your battery compartment a little cleaner. I saw two grains of dust on top of one of your batteries. See ya at KOFA! ;)

Kev
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ
RVI Brake 2, Minder TM-66 TPMS, 960 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

AStravelers

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  • Posts: 1079
  • Part time travelers, 4-8 months each year.
Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #5 on: September 22, 2018, 06:48:11 AM »
Thanks Al and Paul.

My battery temperature was 55 this morning.

See you both in KOFA or Q this year?

Tom
Our winter travel plans are still up in the air so I don't know if we will be in the Q area or even if we will travel this winter.
Al & Sharon
2006 Winnebago Sightseer 29R
2009 Chevy Colorado 4X4

http://downtheroadaroundthebend.blogspot.com/

Gary RV_Wizard

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Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #6 on: September 22, 2018, 08:24:37 AM »
The most obvious reason for those readings is a battery that is getting weak, perhaps just one cell in the entire battery bank.  A modest amp draw knocks the voltage down substantially, so the charge control reacts by going into absorb mode and staying there until it gets the SOC up again.
« Last Edit: September 23, 2018, 12:11:02 PM by Gary RV_Wizard »
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

PJ Stough

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Re: MorningStar TriStar MMPT-45 Overcharging
« Reply #7 on: September 22, 2018, 09:24:49 AM »
We are planning on being at Q again this year, not sure about KOFA.
PJ Stough   Iowa
2005 Winnebago Voyage 38J