Reply
 
Thread Tools Display Modes
Old 11-10-2018, 02:07 PM   #1
Member
 
Join Date: Jul 2017
Posts: 81
Bluetooth battery monitor and shut off switch.

I put a cutoff switch on my battery and also want the Bluetooth monitor

In what order should the cables be placed on the posts?

Do I just put the monitor on top? That would be way too easy.
__________________

mtmurphy56 is offline   Reply With Quote
Old 11-10-2018, 02:28 PM   #2
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 2,431
Quote:
Originally Posted by mtmurphy56 View Post
I put a cutoff switch on my battery and also want the Bluetooth monitor

In what order should the cables be placed on the posts?

Do I just put the monitor on top? That would be way too easy.
If you choose a "Bluetooth Monitor", consider a Victron 712. It uses a shunt that is installed in series with the ground cable from batteries to frame attachment point (usual connection point for RV's).

The shunt needs to be installed in negative/ground cable that is common to all batteries so ALL current in and out of the batteries has to pass through the shunt. Instructions will show where the cable to the batteries is to be connected to the shunt. If you get it backwards it will just show discharge on the monitor itself when the batteries are actually charging.
__________________

__________________
I have it on my dog's authority that an afternoon nap is acceptable.

Politically Incorrect since 1943

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is online now   Reply With Quote
Old 11-11-2018, 12:16 PM   #3
Junior Member
 
Join Date: Jun 2017
Posts: 21
I suspect the OP is referring to one of those small bluetooth "monitors" that simply clamps to both battery posts. Which would be a voltmeter.

While reading voltage alone may certainly meet the needs of some users, I myself consider true battery monitoring with a device capable of the following:
1) Sensing when battery is fully charged, and automatically setting that as the start point for the next discharge cycle
2) Measuring actual total capacity removed from the battery over time during discharge cycle
3) With the above two in hand, battery degradation can be monitored and accounted for each charge/discharge cycle

Unfortunately, the "battery post" monitor only shows voltage, so really does not "monitor" much. While resting battery voltage can be a general indicator of charge state of a LA battery, it is not particularly accurate (especially with some of the newer chemistries that maintain a steady voltage deep into discharge).

The Victor may not account for total system draw (according to an Amazon review their tech support confirmed it does not measure its own usage, also just the way it is wired up it looks like it could be true since a positive wire goes to the shunt, need to verify the negative lead goes to the battery or load side of the shunt). Also, the Victor cannot sense a full battery (user must enter guesstimate of remaining total battery capacity after being fully charged).
__________________
Current TV: 2006 Chevrolet 2500HD Duramax LBZ 4x4
Current RV: 2014 Rockwood A192HW A-Frame
Former RV's: 24' Pioneer travel trailer, Northstar truck camper
rvsixer is online now   Reply With Quote
Old 11-11-2018, 12:28 PM   #4
Senior Member
 
Join Date: Jul 2017
Location: Peoples Republik of Kalifornia
Posts: 1,967
Quote:
Originally Posted by rvsixer View Post
The Victor may not account for total system draw (according to an Amazon review their tech support confirmed it does not measure its own usage, also just the way it is wired up it looks like it could be true since a positive wire goes to the shunt, need to verify the negative lead goes to the battery or load side of the shunt). Also, the Victor cannot sense a full battery (user must enter guesstimate of remaining total battery capacity after being fully charged).
The Victron 712 draws 1mA which turns out to be 0.7AH/month. Likely WAY lower than the battery's self discharge if you are using flooded lead acid.


The Victron does sense a full battery and adjusts the %charge remaining to 100% when it sees that voltage level/current combo. Can't always trust those Amazon reviews. A lot of non technical people providing poor advice. Kinda like what happens here a lot!
__________________
2017 Coachmen 233RBS
2018 Ford F150 Lariat
"Common sense is not very common"
babock is online now   Reply With Quote
Old 11-11-2018, 01:38 PM   #5
Junior Member
 
Join Date: Jun 2017
Posts: 21
Quote:
Originally Posted by babock View Post
The Victron 712 draws 1mA which turns out to be 0.7AH/month. Likely WAY lower than the battery's self discharge if you are using flooded lead acid.


The Victron does sense a full battery and adjusts the %charge remaining to 100% when it sees that voltage level/current combo. Can't always trust those Amazon reviews. A lot of non technical people providing poor advice. Kinda like what happens here a lot!
People also tend to not read or understand fully before responding.
1) My comment for Victron meters was in general, which can use up to 15ma if the battery gets below the 50% capacity remaining guesstimate. If a user forgets to unhook the device for storage, can definitely lead to trouble.
2) I agree don't trust Amazon reviews. Still in this case, the review in question had nothing to do with setting SOC, it did have to do with my stating Victron's may not include their own current usage (if you actually read the review, you will find it took some technical skill to find the condition, which a technical source did verify, and still I mentioned this needs to be verified to make sure it's true, and how to do it).
3) The very first step per Victron user manual is to manually enter the battery capacity.

Anyway, out and best, now into the garage to find out where to put my battery monitor in the a-frame .
__________________
Current TV: 2006 Chevrolet 2500HD Duramax LBZ 4x4
Current RV: 2014 Rockwood A192HW A-Frame
Former RV's: 24' Pioneer travel trailer, Northstar truck camper
rvsixer is online now   Reply With Quote
Old 11-11-2018, 01:57 PM   #6
Senior Member
 
Join Date: Jul 2017
Location: Peoples Republik of Kalifornia
Posts: 1,967
Quote:
Originally Posted by rvsixer View Post
People also tend to not read or understand fully before responding.
1) My comment for Victron meters was in general, which can use up to 15ma if the battery gets below the 50% capacity remaining guesstimate. If a user forgets to unhook the battery for storage, can definitely lead to trouble.
2) I agree don't trust Amazon reviews. Still in this case, the review in question had nothing to do with setting SOC, it did have to do with my stating Victron's may not include their own current usage (if you actually read the review, you will find it took some technical skill to find the condition, which a technical source did verify, and still I mentioned this needs to be verified to make sure it's true, and how to do it).
3) The very first step per Victron user manual is to manually enter the battery capacity.

Anyway, out and best, now into the garage to find out where to put my battery monitor in the a-frame .
If you have the 712 monitor(I wouldn't buy any other model) you will find on their spec sheet that the draw is 1mA....not 10mA.


https://www.victronenergy.com/upload...2-Smart-EN.pdf


Yes you have to enter the battery capacity yourself which may or may not be an exact perfect number.
__________________
2017 Coachmen 233RBS
2018 Ford F150 Lariat
"Common sense is not very common"
babock is online now   Reply With Quote
Old 11-11-2018, 03:02 PM   #7
Senior Member
 
Join Date: Nov 2012
Location: West St. Paul, Manitoba
Posts: 839
Ok so I have a question for all those smarter than I. You have your trailer winterized the battery( s) are left in the RV the solar panels are still functioning and the solar charge controller is maintaining the battery! The battery disconnect switch is engaged to isolate the batteries from the RV. The battery are fully charged controller reads %100. This is no draw or very minimal draw on the battery, nor will there be.
Now lead acid battery (s) self discharge at approximately %5 per month. Your batteries capacity is 220 amp/ hour. The controller sees %100 there is no current flow through the shunt? After a couple of months 220 x %5 x 2 months = 22 amp/ hours is lost from the battery, how would this be replaced?
__________________
Of all the things I've lost in my life the thing I miss the most is my mind!
prairiecamper is offline   Reply With Quote
Old 11-11-2018, 03:10 PM   #8
OYO
Senior Member
 
OYO's Avatar
 
Join Date: Jan 2016
Location: SW Ohio
Posts: 438
Quote:
Originally Posted by prairiecamper View Post
Ok so I have a question for all those smarter than I. You have your trailer winterized the battery( s) are left in the RV the solar panels are still functioning and the solar charge controller is maintaining the battery! The battery disconnect switch is engaged to isolate the batteries from the RV. The battery are fully charged controller reads %100. This is no draw or very minimal draw on the battery, nor will there be.
Now lead acid battery (s) self discharge at approximately %5 per month. Your batteries capacity is 220 amp/ hour. The controller sees %100 there is no current flow through the shunt? After a couple of months 220 x %5 x 2 months = 22 amp/ hours is lost from the battery, how would this be replaced?
Pretty sure I'm not smarter than you, but put the shunt in front of the switch, directly on the battery post. The bluetooth connects to the shunt. The wire on the left goes to the battery post. The one on the right goes to the cutoff switch. The switch goes to the camper.

To the OP. You really need to specify what kind of monitor you want/have.
Attached Thumbnails
Click image for larger version

Name:	20171227_155557.jpg
Views:	31
Size:	289.0 KB
ID:	191207  
__________________
2016 Rockwood A213HW
2010 Silverado LTZ 4x4 Ext Cab

Craig
OYO is offline   Reply With Quote
Old 11-11-2018, 06:17 PM   #9
Senior Member
 
Join Date: Jul 2017
Location: Peoples Republik of Kalifornia
Posts: 1,967
Quote:
Originally Posted by prairiecamper View Post
Ok so I have a question for all those smarter than I. You have your trailer winterized the battery( s) are left in the RV the solar panels are still functioning and the solar charge controller is maintaining the battery! The battery disconnect switch is engaged to isolate the batteries from the RV. The battery are fully charged controller reads %100. This is no draw or very minimal draw on the battery, nor will there be.
Now lead acid battery (s) self discharge at approximately %5 per month. Your batteries capacity is 220 amp/ hour. The controller sees %100 there is no current flow through the shunt? After a couple of months 220 x %5 x 2 months = 22 amp/ hours is lost from the battery, how would this be replaced?
When you recharge. The monitor will not keep track of self discharge but will be accurate again once you complete a full charge.
__________________
2017 Coachmen 233RBS
2018 Ford F150 Lariat
"Common sense is not very common"
babock is online now   Reply With Quote
Old 11-11-2018, 06:37 PM   #10
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 2,431
Quote:
Originally Posted by babock View Post
When you recharge. The monitor will not keep track of self discharge but will be accurate again once you complete a full charge.
Doesn't the "tail current" setting on the BMV-712 provide for this "lost current"? When the tail current drops to a given level which should be the same as the normal self discharge current, the monitor just shows zero current and 100% charge. Or does it?

If that is the case then it would be essential that that tail current setting be accurate. Also, the rest of the settings such as Peukert, Charge Efficiency %, and last but not least, a good "Zero Current" calibration. When I do the latter I just disconnect the ground cable from the frame so Zero current flows but the shunt is still in the circuit and providing power to the monitor.

On the Solar side, I have a Victron Smart Solar Controller (MPPT) and it "networks" with the Monitor. Voltage and battery temp is fed to the solar controller and the rest of the battery parameters are handled by the Monitor.
__________________

__________________
I have it on my dog's authority that an afternoon nap is acceptable.

Politically Incorrect since 1943

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is online now   Reply With Quote
Reply

Tags
battery, switch

Thread Tools
Display Modes

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



» Featured Campgrounds

Reviews provided by


Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 02:39 PM.