SimonP85
Well-Known Member
Can anyone give any feedback (positive or negative) on the Victron BMV 700 series battery monitor? I think I'm 99% sold on the 702 but some forum advice would be useful as always.
Many thanks.
Many thanks.
Victron BMV-700 Battery Monitor
- Thread starter SimonP85
- Start date
PaulRainbow
Well-Known Member
I have a 700. Useful bit of kit for keeping an eye on things. Has some customisable alarms and relay settings too. I have the relay terminals on mine connected to a 12v/240v relay that switches the mains charger on if battery voltages get low.
It does use a negative shut though, so if you have various negative connections at the batteries you will need to make some changes. It's not uncommon for mains chargers, solar controllers, switch panels etc to all have their own connections at the battery. If yours is like this (mine was) you'll need to take all of those to a common point, not the battery, then have a cable from the common point to the shunt and another from the shunt to the battery negative. I connected all of mine to a short bolt. This works well and monitors all of the incoming and outgoing power. I did not connect the engine and windlass negatives (both of those run off of the engine battery) so it won't monitor that use, i presume that it also won't monitor input from the alternator.
It does use a negative shut though, so if you have various negative connections at the batteries you will need to make some changes. It's not uncommon for mains chargers, solar controllers, switch panels etc to all have their own connections at the battery. If yours is like this (mine was) you'll need to take all of those to a common point, not the battery, then have a cable from the common point to the shunt and another from the shunt to the battery negative. I connected all of mine to a short bolt. This works well and monitors all of the incoming and outgoing power. I did not connect the engine and windlass negatives (both of those run off of the engine battery) so it won't monitor that use, i presume that it also won't monitor input from the alternator.
knuterikt
Well-Known Member
That depends on how your batteries share the negative connection, what you want to measure is amps in/out of the house battery.
If your negative from alternator goes to start battery, to common negative to shunt, to house battrey you will measure whats going into house battery but not the share going to start battery. But that is what you want.
The difference between 700 and 702 is that the 702 can measure voltage on secondary (start) battery or midpoint in a multi battery bank.
I would like the display to use a larger font, but apart from that I like it, installation is easy.
SimonP85
Well-Known Member
Thanks all. I fear this may soon get more complicated than I first anticapted but I'd rather fully understand the setup and get it right! Apologies for the badly drawn Paint diagram below but this shows how the negative is arranged at the moment (top) and my suggested setup with the shunt (bottom).
View attachment 63862
At the moment all the negatives go to the negative post on the domestic battery, then onto the engine start and finally the engine ground. The various negatives include standard domestics, solar panel (the +ve for this goes only to the domestic battery), eberSpacher etc...
Hope this makes vague sense!
View attachment 63862
At the moment all the negatives go to the negative post on the domestic battery, then onto the engine start and finally the engine ground. The various negatives include standard domestics, solar panel (the +ve for this goes only to the domestic battery), eberSpacher etc...
Hope this makes vague sense!
pvb
Well-Known Member
If you haven't bought a 702 yet, you might take a look at the new Simarine Pico monitor. I rather like the slick display and multiple features. It will also work as a tank monitor.
View attachment 63865
PaulRainbow
Well-Known Member
Your proposed setup is how it's described in post #3. I would connect all of the negative connections to a bolt and then have a single cable from the bolt to the shunt. The shunt has a 10mm bolt connection, which is likely to be a bit big for your existing terminals. Mine are all connected to a 8mm stainless bolt.
PaulRainbow
Well-Known Member
I hadn't actually considered monitoring the alternator output to the domestic bank until i was typing post #2. My battery negatives are all in parallel so won't be monitored. I'll have to make a couple of new negative cables up at some point.
knuterikt
Well-Known Member
to have the monitor display correct SOC it must measure all amps in and out of the battery.
PaulRainbow
Well-Known Member
Yes, i know that. But, i don't use the engine too much and the BMV auto sync's every time the battery is charged anyway, so it's not the end of the World. It just means that if i run the engine the BMV will think the battery is fully charged, even if it isn't. I will make a couple of new negative cables up as soon as i get time though.
gregcope
Well-Known Member
I have a 702. Easy to install. I had to re-arrange a few negative connections from direct to the batteries to a common ground (a bolt). I also had to make another negative connnectoin from the shunt to the batteries but this was easy.
I like it and would recommend it. Go for it. Victron stuff is good. I have an 75/15 MPPT controller. Their tech support is good too.
I like it and would recommend it. Go for it. Victron stuff is good. I have an 75/15 MPPT controller. Their tech support is good too.
PaulRainbow
Well-Known Member
Should also mention the Victron USB cable that allows everything to be monitored from a PC or tablet, including up to 30 days historical data.
Yngmar
Well-Known Member
Victron stuff is great and their documentation is excellent, not to mention they publish all the pinouts and protocols used, just like all manufacturers should do.
The only thing that bothers me a bit about the BMV (and MPPT control which uses the same exact housing) is that the display and letters are tiny, and so are the buttons. This may or may not be an issue depending on where and how you want to use it. I certainly prefer the huge digits on the Nasa BM (I have that for monitoring the house bank and a Victron MPPT Control for the solar bits), simply because I can read it from across the cabin or peeking down the companionway from the cockpit.
The only thing that bothers me a bit about the BMV (and MPPT control which uses the same exact housing) is that the display and letters are tiny, and so are the buttons. This may or may not be an issue depending on where and how you want to use it. I certainly prefer the huge digits on the Nasa BM (I have that for monitoring the house bank and a Victron MPPT Control for the solar bits), simply because I can read it from across the cabin or peeking down the companionway from the cockpit.
dunedin
Well-Known Member
Or the Bluetooth connector - which gets onto phone or tablet without wires.
Also addresses the screen size issue.
(Though was an update to the App today and as of a few minutes ago had lost connectivity from the new App - hopefully will be resolved quickly if they have good support)
SimonP85
Well-Known Member
All
Many thanks for the replies, very useful as always.
There are a number of connections that will need to be moved which are all on M8 connections to the battery post terminal (see photo below). Rather than re-crimping all these to M10 for the shunt I like the idea of moving to a M8 bolt. I can then get a short lead made up with M8 at one end and M10 at the other to go from the bolt to the shunt and another from the shunt to domestic battery.
For now I'll stick with the standard display but I'd noted the Bluetooth connector which might be a nice addition in the future.
View attachment 63937
Many thanks for the replies, very useful as always.
There are a number of connections that will need to be moved which are all on M8 connections to the battery post terminal (see photo below). Rather than re-crimping all these to M10 for the shunt I like the idea of moving to a M8 bolt. I can then get a short lead made up with M8 at one end and M10 at the other to go from the bolt to the shunt and another from the shunt to domestic battery.
For now I'll stick with the standard display but I'd noted the Bluetooth connector which might be a nice addition in the future.
View attachment 63937
PaulRainbow
Well-Known Member
I have the Bluetooth dongle on my solar controller and he USB cable on the battery monitor. Both are useful. I can't get the dongle to work on Windows 7 (laptop), but i've just ordered a Samsung tablet that's running Windows 10, hopefully that will and i can get both on the tablet.
dunedin
Well-Known Member
Why bother with windows. Should work fine on Android or Apple phone or tablet (mine works with iPad and elderly Samsung Galaxy phone)
Suspect Win 7 device had older Bluetooth spec.
PaulRainbow
Well-Known Member
The dongle works fine with Android on my tablet and phone. The tablet has just passed away though and i needed to buy another. I also have a failing Windows laptop with some diagnostic software the will only run on Windows. So, i've gone for a 12" Samsung Galaxy Pro S, running Windows 10. That'll run my diagnostics stuff and i can run OpenCPN on it with a feed from my NMEA > wifi router, so i'll get the full N2K network data on the tablet.
I think you're right about the old spec bluetooth, it's a bluetooth dongle that's a few years old. The new tablet has Bluetooth built in, so hopefully i can run two copies of the Victron Connect software and see the controller and BMV data on one screen.
Dockhead
Well-Known Member
I have a few years of experience with two of them, and frankly, I don't like them. They are good ammeters (and that is a useful function), but the way they calculate state of charge doesn't work well, and is prone to dangerous errors (overstating the real state of charge).
The Merlin SmartGage is, within its own limitations, far more accurate. Its limitations are that it poorly guesses at state of charge achieved during charging or just after a partial charge, and doesn't really work if you're getting some charging current coming in from solar or wind.
Simple voltage reading (but the voltmeter must be connected directly to the batts) with temperature correction and read against an open circuit voltage vs. SOC chart also works very well so long as your loads are reasonably small compared to the bank capacity. This will slightly underestimate the real SOC (on account of the loads pulling the voltage down), but all errors are harmless. Subject to the same limitations as SmartGage, but this is more accurate and far more foolproof, than using an amp-counting battery monitor like the Victron.
These observations are backed up with a lot of testing I did against specific gravity readings in my boat.
The Merlin SmartGage is, within its own limitations, far more accurate. Its limitations are that it poorly guesses at state of charge achieved during charging or just after a partial charge, and doesn't really work if you're getting some charging current coming in from solar or wind.
Simple voltage reading (but the voltmeter must be connected directly to the batts) with temperature correction and read against an open circuit voltage vs. SOC chart also works very well so long as your loads are reasonably small compared to the bank capacity. This will slightly underestimate the real SOC (on account of the loads pulling the voltage down), but all errors are harmless. Subject to the same limitations as SmartGage, but this is more accurate and far more foolproof, than using an amp-counting battery monitor like the Victron.
These observations are backed up with a lot of testing I did against specific gravity readings in my boat.
ex-Gladys
Well-Known Member
The newer tablets/laptops come with BT 4(IIRC) which will retroconnect with earlier versions. A while ago I had to buy a dongle, because a BT4 mouse wouldn't connect to my old Lenovo laptop
PaulRainbow
Well-Known Member
Unfortunately the Victron software still doesn't see the dongle, although the new tablet pairs with it. Will investigate at some point, but too busy just now.
