Jump to content

Battery monitor

goodboy

By goodboy
in Boat Equipment

 Share

Featured Posts

goodboy Gongoozler

goodboy

Posted
Posted

hi all i'm thinking of buying a battery monitor either smartgauge / nasa / victron ect,

what would you buy and why, what do you have and how do you like it,i would like the

smartgauge but would like something that shows amps in and out.

thanks team.

Link to comment
Share on other sites
Keeping Up Veteran II

Keeping UpDonate to Canal World

Posted
Posted

I bought the NASA BM2 because it shows amps in/out as well as volts on a nice big clear display. Its SoC figures don't seem to be very accurate unless you do a lot of fiddling, but having done that fiddling you also then get a readout of your battery's capacity which is useful. Personally I'm very pleased with it and I'm convinced it was the right choice for me.

Link to comment
Share on other sites
bottle Veteran II

bottle

Posted
Posted

I've got the Victron bmv602, does it's job and it can start by generator via the alarm relay when it gets to a certain voltage or SOC%. Only lacking us I wish I could program it too start the genny when a high load is switched on.

 

I assume you mean a high load 240v ac and not knowing your other equipment so this is a generic answer. wink.png

 

My Victron combi will do that, ie. start generator on a large load and also control how long the generator runs.

Link to comment
Share on other sites
Robbo Veteran II

Robbo

Posted
Posted

 

I assume you mean a high load 240v ac and not knowing your other equipment so this is a generic answer. wink.png

 

My Victron combi will do that, ie. start generator on a large load and also control how long the generator runs.

Could be either AC or DC high load, but can't think of a DC high load (bar inverter!). My Victron combi is too old for that. Is there any other equipment you need for combi to switch the genny on or is via the alarm relay? I know they did a module for the Ve.net system to control a generator but this is now discontinued.

Link to comment
Share on other sites
bottle Veteran II

bottle

Posted
Posted

It is done via the 'virtual switch' programmable with VE config, software, downloadable from Victron site, and a laptop with suitable inter connection.

 

As the virtual switch is non load bearing, it signals a suitable relay (not standard car type, activating coil load to high) that connects to a generator controller.

 

Mine was all done before I got the boat, so only know what is there. wacko.png

Link to comment
Share on other sites
Robbo Veteran II

Robbo

Posted
Posted (edited)

It is done via the 'virtual switch' programmable with VE config, software, downloadable from Victron site, and a laptop with suitable inter connection.

 

As the virtual switch is non load bearing, it signals a suitable relay (not standard car type, activating coil load to high) that connects to a generator controller.

 

Mine was all done before I got the boat, so only know what is there. wacko.png

 

Thought it would be (and just confirmed by looking at the manual for veconfig), my combi is too old and doesn't have a alarm relay or configurable via veconfig. Seems daft why they didn't add the load option to the BMV!

Edited by Robbo
Link to comment
Share on other sites
MtB Veteran II

MtBDonate to Canal World

Posted
Posted

NASA BM1 or BM2.

 

I definitely want to see amps in and out, and instantaneous voltage. SOC is secondary as it can be educated ly guessed from voltage.

 

Ideally, I would have a Smartguage aswell, but can't currently justify the expense.

 

Do you mean amp-hours in and out? Amps in and amps out is pretty meaningless at any given point in time.

 

MtB

Link to comment
Share on other sites
goodboy Gongoozler

goodboy

Posted
  • Author
Posted

Thanks everyone for your input.

I found bottles link very good .it seems people like what thay have at the moment and for good reasons.

For me i think it will be the bmv700 or the NASA bm2 or merlin power gauge lite

Similar features and price, I need to know amps in and amps out at any given time.

Link to comment
Share on other sites
by'eck Veteran

by'eck

Posted
Posted

Do you mean amp-hours in and out? Amps in and amps out is pretty meaningless at any given point in time.

 

MtB

No I'm sure he wants to monitor current in and out of batteries which is far from meaningless. The amp hour counter will use this data against time to calculate amp hours in or out of batteries.

 

Apologies to the OP for stating the obvious but a single shunt placed in the main battery feed adjacent to batteries, will record amps in minus amps out at any point in time. This could easily therefore be a negative value.

Link to comment
Share on other sites
Keeping Up Veteran II

Keeping UpDonate to Canal World

Posted
Posted

Agreed. As well as volts I want to see amps in while I'm charging to get an idea of how the charging is going, and amps out when the engine has stopped to check if I'm wasting power, then amp-hours to see how much is left to put in or take out, and finally in priority SoC to see the effect of all that on my batteries. For me the NASA BM2 does that admirably but I know that some others prefer the way that other monitors display the information.

Link to comment
Share on other sites
Loafer Veteran

Loafer

Posted
Posted

FWIW, my own studies of the Victron BMV 600S, a good piece of kit, show that SOC is the least-reliable bit of information it provides. It is only a calculation, based upon loads of assumptions. You can even program those 'assumptions' to change the resulting SOC figure.

 

The best judge of your batteries' SOC is YOU, after a suitable period of interest and growing knowledge of your DC power system. At any moment, you would soon be able to read the voltage, the current draw at the moment of measuring that voltage, and then take a very good guess at your SOC.

 

Offline peeps with large, daily-cycling charge states, need to re-set 'SOC' readings occasionally or else it means very little.

 

Unless I am very much mistaken.

Link to comment
Share on other sites
nicknorman Veteran II

nicknormanDonate to Canal World

Posted
Posted (edited)

The Smartgauge is by far the best device for showing actual state of charge on discharge, which is perhaps the most important single parameter. Actual state of charge relative to the batteries' current capacity, rather than theoretical state of charge based on the capacity on the label. The number of folk I know who complain of the lights going out when their AH - counting gauge is showing 80% SoC!

 

Add an ammeter, this lets you know when to stop charging and helps to know how much juice things use.

 

Ideally the ammeter includes an AH counter so that you can get a good idea of the batteries' health by comparing that with the Smartgauge.

 

If you consider the cost of battery bank replacement, and the inconvenience of having a battery health crash at an inopportune moment (like Christmas!), having both a Smartgauge and an AH counting gauge does not seem overly extravagant.

Edited by nicknorman
Link to comment
Share on other sites
smileypete Veteran II

smileypete

Posted
Posted (edited)

Thanks everyone for your input.

I found bottles link very good .it seems people like what thay have at the moment and for good reasons.

For me i think it will be the bmv700 or the NASA bm2 or merlin power gauge lite

Similar features and price, I need to know amps in and amps out at any given time.

BMV etc needs a good understanding of its settings to make full use of it, so maybe not for everyone. Smartgauge is a lot more forgiving in this respect.

 

Amps only really become important for 'power audits', FULLY charging batts,and fault finding.

 

If CCing full time it's well worth having a good understanding of batt charging and so on.

 

cheers, Pete.

~smpt~

Edited by smileypete
Link to comment
Share on other sites
Arthur Brown Influencer

Arthur Brown

Posted
Posted

100 years ago, people lived on boats without electricity, 50 years ago people lived on boats with just a little electricity. NOW we live on a small power station and expect 240 and 12v on tap without any glitches. For a residential boater, especially off grid, a good understanding of your own electrical system is essential. Otherwise it's back to solid fuel and lamp oil at the most inopportune moments.

 

Smartgauge, multimeter and DC clamp meter would be my choice for a start.

Link to comment
Share on other sites
Groundhog Engager

Groundhog

Posted
Posted

I've ordered a Smargauge/Smartbank advance for the two useful functions of paralleling my alternators and giving me an accurate soc for my batteries. I'm also going to fit a Victron BM700 to give me an idea of power usage both at any given moment and amp hours used over a given period. I'm going for the Victron as it comes with a 500amp shunt, I have a 3kw inverter. I think these devices combined will tell me everything I need to know to build a picture of what's going on with my batteries and electrical system generally.

 

I'm no altogether pleased with a number of aspects of the way my boat is currently wired up at the battery end so while I get everything sorted to the way I want it (the smargauge site is a mine of information) I'm also going to fit a couple of cheap shunt digital ammeteres to each alternator feed while I'm at it so I have a complete picture of my system on hand.

Link to comment
Share on other sites
nicknorman Veteran II

nicknormanDonate to Canal World

Posted
Posted

I've ordered a Smargauge/Smartbank advance for the two useful functions of paralleling my alternators and giving me an accurate soc for my batteries. I'm also going to fit a Victron BM700 to give me an idea of power usage both at any given moment and amp hours used over a given period. I'm going for the Victron as it comes with a 500amp shunt, I have a 3kw inverter. I think these devices combined will tell me everything I need to know to build a picture of what's going on with my batteries and electrical system generally.

 

Yup, sounds like a good setup to me.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.