Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 06-16-2022, 09:28 AM   #1
eblues's Avatar
Join Date: Nov 2017
Posts: 42
BMV-712 Temp reading high

I installed a Victron BMV-712 with the correct temp sensor about a yr ago and it has worked fine until I recently noticed the temp was indicating about 200 deg F. Everything else appears to be normal. After disconnecting and reconnecting the temp sensor fuse, the temp indication returns to where it should but slowly begins to ramp back up. After 1-2 days its indicating ~200 deg again.

I bought the monitor and sensor from different sources and have reached out to both of them but no response yet. Any suggestions or ideas?

The monitor is connected to 4 FLA batteries. Ambient temp is 60-75 and I have a remote sensor connected to a weather station monitoring battery compartment temp. Batteries feel at ambient temp to the touch.
21 Bay Star 3226, 12 JKU Rubicon
96 SeaRay 270DA
eblues is online now   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-16-2022, 04:18 PM   #2
Senior Member

Join Date: Sep 2017
Location: Northern California
Posts: 1,075
The temperature sensor is likely a thermister. The resistance of a thermister rises with temperature or drops with temperature depending on the type of thermister (NTC or PTC). The BMV-712 measures resistance of the thermister to ascertain temperature. So it's possible there's something affecting resistance in the wiring or maybe the sensor itself. I.e., a bad connection somewhere along the line would introduce additional resistance and a high reading (PTC). In the other case, a short of some kind could do the same (NTC). I don't know what type Victron uses in the BMV-712 but I suppose it doesn't matter. It seems the problem is either a bad connection that is introducing extra resistance or a short of some kind that is pulling resistance down. So it could be a wiring problem. Or, of course, it could be a flakey sensor. I'd trace out the wiring from the BMV-712 to the sensor and if you don't see a problem, disconnect the sensor wires at the BMV-712 and put an ohmmeter across them and warm and cool the sensor, wiggle it, etc. looking for other than a nice smooth change in resistance as the temperature changes. If you don't see predictable ohm readings and the wiring looks good, suspect the sensor itself.
2020 GMC Denali 2500HD Crew 4X4 Gas 6.6L
Rockwood 8280WS (30' 5th)
Solar and LiFePO4. 12V NovaKool fridge
hclarkx is offline   Reply With Quote
Old 06-22-2022, 03:53 PM   #3
eblues's Avatar
Join Date: Nov 2017
Posts: 42
Thanks hclarkx. The wiring is simple & looks good, connections are clean. As you suggested I disconnected the sensor wiring from the shunt & connected an ohmmeter ... the resistance varied (drops w/ temp incr) smoothly while the sensor warmed & cooled. I'll check it over a day or two to see if it remains constant. If it does I'll pursue getting a new shunt under warranty.
21 Bay Star 3226, 12 JKU Rubicon
96 SeaRay 270DA
eblues is online now   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Victron BMV-712 Battery Monitor vsheetz RV Systems & Appliances 41 05-29-2019 05:18 AM
Victron BMV 712 Bluetooth pin code Unicorn Driver RV Systems & Appliances 5 02-04-2019 09:07 AM
Victron BMV 712 App solar question Unicorn Driver RV Systems & Appliances 4 01-06-2019 07:51 AM
Victron BMV 712 Dead NealC Going Green 7 12-05-2018 02:04 PM
Location of Victron BMV 712 Monitor Vtwin996 General Discussion 1 06-24-2018 02:06 PM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 05:25 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.