Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 19-08-2014, 22:14   #31
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,426
Re: State of Charge

Just about 3 days ago I installed a balmar smart gauge alongside my mastervolt. So far, I feel like I'm getting much better data from the balmar. It says in the instructions that it takes 4 days to sync properly but what I am seeing from this gauge makes much more sense than what I'm seeing from the mastervolt.

Basically, the mastervolt is showing me being full when I reach float voltage (13.2) rather than absorption target voltage (14.8). So it's saying I'm at 99% full while the smart gauge was showing low 80's. It took almost all day with my solar and wind to get up to 98% charge on the smart gauge.

The mastervolt is also way off on voltage readings. When charging the mastervolt and smart gauge show very close voltages but when drawing down, the mastervolt reads a much lower voltage... About .2 volts. So my volt meter and my smart gauge read the same but my $700 mastervolt shunt is way off.

Incidentally, when I asked my mastervolt dealer about the discrepancy he had nothing to say and the line has suddenly gone dead. Since I'm still within my 1 year warranty I think I'm going to challenge the install on my credit card. I tried to get him to test it many moons ago but he claimed I needed to drive the boat back to Maryland from the Carolina's. I bet I get a referral to a local mastervolt dealer real quick. Mastervolt has only ever responded to one generic email I sent in regards to how they define a charge cycle, so I'm generally displeased with their customer service as well.


Sent from my iPad using Cruisers Sailing Forum
__________________

__________________
zboss is offline   Reply With Quote
Old 22-08-2014, 02:57   #32
Registered User

Join Date: Mar 2012
Location: On board in Alanya, Turkey
Boat: Hunter Legend 420 Passage
Posts: 626
Re: State of Charge

Quote:
Originally Posted by zboss View Post
Just about 3 days ago I installed a balmar smart gauge alongside my mastervolt. So far, I feel like I'm getting much better data from the balmar. It says in the instructions that it takes 4 days to sync properly.....
The manual says 2-3 charge cycles to sync, not 4 days! The longer you use it and take it from 100-50% SoC the more accurate it will become.

Anyone who has the 10 year old original SmartGauge should download the new Balmar Manual which is much more helpful.

Don't be too hard on Mastervolt as ALL shunt based BMs can become inaccurate as the batteries age. I suspect your 0.2v drop on load compared to fully charged is an installation problem. The voltage sense wires MUST go to the positive stud of the battery and the load side of the shunt. Saving cables and installation time by wiring these positive and negative wires to master switches or to the engine block negative will cause a voltage drop.
__________________

__________________
sailinglegend is offline   Reply With Quote
Old 22-08-2014, 16:47   #33
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,426
Re: State of Charge

I'm pretty sure the installation was done very well, the marine installer engineer did a spectacular job at the wiring. The shunt is connected properly.

The issue is the voltage reading not the amp reading. I can see no reason why the voltage reading would be so far off. Voltage readings should not wander over time... The voltage is the voltage.

What is perplexing is that my wind generator regulator, which has a voltmeter on it also, shows the correct voltage. So, it's only the master volt meter in between that shows the incorrect voltage. This says to me a bad circuit board or bad software.


Sent from somewhere other than where I want to be!
__________________
zboss is offline   Reply With Quote
Old 22-08-2014, 18:20   #34
Moderator Emeritus
 
Ex-Calif's Avatar

Cruisers Forum Supporter

Join Date: May 2007
Location: Singapore
Boat: Maxi 77 - Relax Lah!
Posts: 11,514
Images: 4
Re: State of Charge

Glad to hear about the SmartGauge. Mine is in transit as we speak...
__________________
Relax Lah! is For Sale <--- Click
Click--> Custom CF Google Search or CF Rules
You're gonna need a bigger boat... - Martin Brody
Ex-Calif is offline   Reply With Quote
Old 22-08-2014, 19:35   #35
Registered User
 
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,649
Re: State of Charge

It's more than likely a bad (ground) connection.
__________________
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Old 22-08-2014, 21:41   #36
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,426
Re: State of Charge

Quote:
Originally Posted by Terra Nova View Post
It's more than likely a bad (ground) connection.

But there is only two wires in an two wires out. If it was a grounding fault at the master shunt, a) I would get a warning, b) anything after that shunt would show a similar drop in voltage. This is not what happens. A voltmeter placed both before and after the shunt read higher voltages than the shunt.


Sent from my iPad using Cruisers Sailing Forum
__________________
zboss is offline   Reply With Quote
Old 22-08-2014, 22:13   #37
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,450
Re: State of Charge

ZB, perhaps I am misreading your post, but the shunt itself is not involved in the measurement of the system voltage. Its sole purpose is to measure the current flowing through it. The shunt is nothing but a very low ohm resistor in series with the main buss. You measure the current by measuring the voltage drop across this resistance. If you were to measure the voltage above ground (or below line voltage if the shunt is in the negative lead) on both sides of the shunt, the difference is a few millivolts or so, depending on the current.

I agree that it sounds like the voltmeter in your monitor is out of calibration. A poor connection in that circuit will not make much of a reading difference because the current drawn by the voltmeter is extremely low. Thus the voltage dropped in a poor connection is tiny and will not make a big difference in the reading.

Out of calibration instruments really bug me... I sympathize with your frustration.

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 22-08-2014, 22:24   #38
Moderator Emeritus
 
Ex-Calif's Avatar

Cruisers Forum Supporter

Join Date: May 2007
Location: Singapore
Boat: Maxi 77 - Relax Lah!
Posts: 11,514
Images: 4
Re: State of Charge

Quote:
Originally Posted by zboss View Post
But there is only two wires in an two wires out. If it was a grounding fault at the master shunt, a) I would get a warning, b) anything after that shunt would show a similar drop in voltage. This is not what happens. A voltmeter placed both before and after the shunt read higher voltages than the shunt.


Sent from my iPad using Cruisers Sailing Forum
I have scrolled up and down this thread but can't find the model number of your mastervolt BM.

Care to share?

<edit> what is getting me is your statement about only 4 wires. The BTMIII for example can have up to 7. The shunt (amp measuring) is separate from the voltage sensing - it requires 2 wires. The voltage sensing requires 1 wire per bank (up to 3). Then you need power and ground for the unit (2 wires)

The shunt will have only 4 connections. But that is not where voltage is being measured.

http://images.mastervolt.nl/files/Qu...II061113EN.pdf
__________________
Relax Lah! is For Sale <--- Click
Click--> Custom CF Google Search or CF Rules
You're gonna need a bigger boat... - Martin Brody
Ex-Calif is offline   Reply With Quote
Old 22-08-2014, 23:05   #39
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 6,385
Re: State of Charge

Quote:
Originally Posted by ontherocks83 View Post
Can you elaborate on this a little? I can understand the 14.4v and 1.5% being full but after it hits that it eventually goes to float voltage. Why is float not considered full? I'm sure I'm missing something obvious I just don't know what it is.
Glad you Got It from MS's explanation.

Another way to say it is:

FLOAT IS NOT FULL

The only way to determine a full bank is when the voltage is ___ and the acceptance is less than ________ % of C.

__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 23-08-2014, 03:52   #40
Registered User

Join Date: Mar 2012
Location: On board in Alanya, Turkey
Boat: Hunter Legend 420 Passage
Posts: 626
Re: State of Charge

Quote:
Originally Posted by Stu Jackson View Post
FLOAT IS NOT FULL....
I think it's always easy to explain that unless a charger is actually measuring the current going into the battery AND it knows the size of the bank then it can't know when it's full! Hence chargers are designed to 'charge' your battery and not 'overcharge' it, so almost all if them will switch to Float before the battery is full.
__________________
sailinglegend is offline   Reply With Quote
Old 24-08-2014, 10:40   #41
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,426
State of Charge

It's a mastershunt 500.

http://www.mastervolt.com/marine/pro...h-system-fuse/


When I'm referring to the shunt I mean the unit as a whole not the shunt component. In this particular design they are one and the same.

The mastervolt "shunt" reads the voltages and current and sends the data to the remote display over master connect.


Sent from somewhere other than where I want to be!
__________________

__________________
zboss is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Technical question - bank state-of-charge question Zanshin Electrical: Batteries, Generators & Solar 11 17-01-2014 12:10
Battery state of charge sailorboy1 Electrical: Batteries, Generators & Solar 50 27-06-2012 10:16
Washington State purchase with out-of-state residence cyclepro Dollars & Cents 7 06-06-2011 09:55
State by State Nonresdient Regs Stoney Rules of the Road, Regulations & Red Tape 2 10-06-2008 09:52
To Charge or Not to Charge... alexleclainche Engines and Propulsion Systems 2 12-06-2007 22:31



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 07:04.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.