Problem with Victron battery monitor

May 6, 2010
472
1984 Oday 39 79 Milwaukee
Reposting this as my mobile phone spell (in)corrected the title last time!

I have a 602s which I installed early this year in a boat with two battery banks. The batteries on the primary bank are new this year. Every few weeks the monitor will suddenly lose all history, and the SOC, CE and TTG fields will display just dashes. In no case was the state of charge below 90% when these events occurred. I can’t be sure, but these events may have happened while starting the motor. The installation of the monitor was done in conjunction with a complete re-wire of the entire starting and charging system, so all connections, cables etc are new. We are in fresh water environment. I am wondering if you can offer some suggestions as to how to go about trouble shooting an intermittent problem such as this?
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
some time when i install gadgets i have to go back and reread the installation instructions again and again just to satisfy that i have it correct and some times i find some little thing that i have done incorrectly like hooking up a wire to the wrong part of a circuit...some of this tuff is very fussy about where it wants to be hooked up...then it gets in to programing and that is another world altogether and i have to read and reread the program instructions several times ...so to answer your question i have not installed one of theses yet but when i do i am sure i will go through what i have described again...maybe some one here will know your problem and help you ...good luck
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Reposting this as my mobile phone spell (in)corrected the title last time!

I have a 602s which I installed early this year in a boat with two battery banks. The batteries on the primary bank are new this year. Every few weeks the monitor will suddenly lose all history, and the SOC, CE and TTG fields will display just dashes. In no case was the state of charge below 90% when these events occurred. I can’t be sure, but these events may have happened while starting the motor. The installation of the monitor was done in conjunction with a complete re-wire of the entire starting and charging system, so all connections, cables etc are new. We are in fresh water environment. I am wondering if you can offer some suggestions as to how to go about trouble shooting an intermittent problem such as this?
Need a LOT more information..

How is it wired exactly?

What gauge battery wires?

Where does the small red wire connect to?

What size type and brand of battery?

How exactly are the batteries wired?

How exactly are the batteries used?

How many ampere hours are the batteries?

How was the monitor programmed? Specific settings.

How do you know you were at 90% SOC?

What are the charging sources? Type, brand etc...
 
Jun 7, 2004
36
Catalina 320 Middle River, MD
Just wondering

Gee, when my hearing aids stop working I just change the batteries. Why can't boats be more like my hearing aids?
 
May 6, 2010
472
1984 Oday 39 79 Milwaukee
Need a LOT more information..

How is it wired exactly?
Attached is a wiring diagram.

What gauge battery wires?
See diagram - bank #2 is approximately 10' - 12' run one way - probably could have gone heavier on the cable but that was the max for my crimper. Our Universal M25 always starts on the turn of the key - I never have to crank it.

Where does the small red wire connect to?
One goes to the + terminal of battery #1, one goes to the battery #2 + cable where it is connected to the fuse buss bar for the main battery switch, service disconnect and charger.

What size type and brand of battery?
Duracell Procell 6V golf cart 244 ah

How exactly are the batteries wired?
See diagram

How exactly are the batteries used?
Bank #1 is reserve and inverter (used for occasional laptop power or bluetooth speaker charger), bank #2 is used for starting and house loads, which are just lighting, stereo, and instruments - speed and depth, and occasional auto helm.

How many ampere hours are the batteries?
244 each

How was the monitor programmed? Specific settings.
I'm sorry I don't recall specific numbers but I programmed it based on the Victron setup manual for my battery rating

How do you know you were at 90% SOC?
The monitor will work fine for a few weeks, then all of a sudden it loses it's history and will just display dashes in the CE, SOC and TTG fields until I manually recalibrate it.

What are the charging sources? Type, brand etc...
Standard 55A alternator (rewired with Catalina panel - eliminating the trailer connectors) and Xantrex TruCharge 20. 95% of the charging is alternator, although we just spent a weekend on shore power about a week prior to the last memory loss incident. The boat is on a mooring, and we typically stay on the boat Friday nights and sail Saturday and sometimes on Sunday. I don't think I've ever seen the monitor display less than 90% since I installed it early this season. After the memory loss incidents, I have charged it on shore power until the input is under 2A, then manually re-calibrated.

Thanks,
Scott
 

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Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
It sounds like it is losing power at some point.. These won't reset until 9 volts about 7-8 seconds at 9 volts... You might check the in-line fuse or your batts may be getting weak??
 
May 6, 2010
472
1984 Oday 39 79 Milwaukee
It sounds like it is losing power at some point.. These won't reset until 9 volts about 7-8 seconds at 9 volts... You might check the in-line fuse or your batts may be getting weak??
I agree, although I am confused now - I was also of the understanding that it would take several seconds at low voltage to lose memory however Victron tech support told me that less than a second at low voltage (below 8 volts) is enough to reset it.

I guess I need to get out the Fluke and see what is going on. Although it starts immediately is it possible the starter is causing a momentary drop sufficient to reset it?
 
Jan 10, 2011
342
Macgregor 25 675 Lake Lanier
If your batteries are good then you may be pulling too much juice with the starter indicating it is about to give you that quiet sound when you want your engine to start.