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Post by tomten on Jan 23, 2017 14:22:28 GMT
Hi there.
Going to install victron easysolar, (inverter, charger, solar controller and AC distribution all in one box, just connecting DC cables to battery and all charging and AC electrics are deals with!)
Have always been sold on smartguage, but have heard very good things about victron components integrating with each other, so I wonder if a BMV would make more sense?
I understand that BMV measures current via a shunt, while smartguage takes calculations from voltage, but what real world differences will this make?
Or should I be looking at both?
Thanks in advance.
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Post by phil70 on Jan 23, 2017 15:37:31 GMT
I use a Merlin Power Gauge Lite, this preceded the Smartgauge. It is a shunt based bit of kit, tells the voltage of both the domestics' and the starter, shows amps in and out and shows amp hours used and percentage of charge remaining. I know that it is not 100% but it gives me enough to work with coupled with experience. Many people swear by Smartgauge but by the same token many people have never used anything before getting a Smartgauge, I think there is an argument for using both. Others will be along shortly to rubbish my post ☺ Phil
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Post by pearley on Jan 23, 2017 17:02:42 GMT
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Post by peterboat on Jan 23, 2017 17:21:36 GMT
I have a NASA BM 2 it works fine for me I wanted to see amps coming in going out which a smartgauge doesnt do, however would a smartgauge be better if I didnt need to see amps? plenty of very well qualified people seem to think so and that has to go some way towards a choice
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Post by smileypete on Jan 23, 2017 17:34:31 GMT
For people who aren't that interested in boat electrics, a Smartguage is a more user friendly choice I believe.
The others require careful setup and awareness of their limitations, or can end up telling downright lies
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Post by IainS on Jan 23, 2017 19:08:06 GMT
It's not really a case of "versus". The Smartgauge is very good at giving percentage charge, but doesn't give current or capacity information. The BMV attempts to work out percentage charge, but does it by counting Amphours, and becomes inaccurate with time, and that's assuming it was set up correctly in the first place.
Kelpie had a Merlin Powergauge when we bought her. I added a Smartgauge, and feel they compliment each other, rather than competing. Using the two gauges, it is easy to estimate REAL battery capacity by comparing Ah out with percentage discharge. Both instruments measure voltage (although the Powergauge doesn't do starter battery voltage), Powergauge gives Amps and Ah out, but it's state of charge reading is very suspect, although it can be "tuned" against the Smartgauge by adjusting capacity and "Peukert Factor", which improves its accuracy, although there's really no need to do so; just look at the Smartgauge!
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Post by pearley on Jan 23, 2017 20:08:01 GMT
For people who aren't that interested in boat electrics, a Smartguage is a more user friendly choice I believe. The others require careful setup and awareness of their limitations, or can end up telling downright lies Sorry but thats rubbish. I'm interested in my boats electrics and keep a careful watch on my batteries, but choose to do it via a Smartguage.
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Post by smileypete on Jan 23, 2017 20:16:15 GMT
For people who aren't that interested in boat electrics, a Smartguage is a more user friendly choice I believe. The others require careful setup and awareness of their limitations, or can end up telling downright lies Sorry but thats rubbish. I'm interested in my boats electrics and keep a careful watch on my batteries, but choose to do it via a Smartguage. All I was meant, is that if you weren't that interested in boat electrics, a smart gauge would be a more user-friendly choice. Now, if you ARE interested in boat electrics, then it's down to personal preference presumably...
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Post by Robbo on Jan 23, 2017 20:18:36 GMT
The BMV is a nice battery monitor, but it is a amp hour counter and these have flaws when coming to the percentage of discharge (any amp hour counter does). The smartguage doesn't have this flaw due to using a different method of showing the percentage (but when charging it's not that accurate, good when discharging).
However, if you know how to read them a voltmeter and amp meter is all that's really needed.
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Post by tomten on Jan 23, 2017 22:22:11 GMT
Thanks for the comments all.
I am interested in my boat electrics, my wife and children less so. I want to install something with as accurate and foolproof as possible Soc reading, sounds like the smartguage.
But I will probably look to install a BMV in the fullness of time to satisfy my own interests (not sure budget will allow it straight away...)
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Post by tonyb on Jan 24, 2017 8:27:40 GMT
Guide to the correct answer to you in the Advice and Guidance section under Why do amp hour counters (BVM) tell lies.
I get by happily with a voltmeter and ammeter but to do so needs understanding so I have not voted.
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Post by canaldweller on Jan 24, 2017 10:50:47 GMT
Thanks for the comments all. I am interested in my boat electrics, my wife and children less so. I want to install something with as accurate and foolproof as possible Soc reading, sounds like the smartguage. But I will probably look to install a BMV in the fullness of time to satisfy my own interests (not sure budget will allow it straight away...) If you are going to get a Smartguage then why not spend a couple of pounds more and get an ammeter as well. Between the two you should be able to learn all about your batteries and charging. So, when the "fullness of time" comes around, you'll possibly realize that you have learnt enough not to need a BMV.
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Post by Telemachus on Jan 24, 2017 18:07:23 GMT
They show different things and do so with differing accuracy. The BMV gives you current and AH consumed accurately but it's SoC indication during discharge is likely to be inaccurate, probably over-reading.
The SG doesn't give current or AH used but is pretty good for SoC during discharge. With a bit of experience it hints at the health of the batteries, ie if you notice the SoC is dropping off more quickly than it used to, it means the actual capacity if the batteries has fallen.
So BMV best for seeing what is going on with loads and charging sources, and is thus good at telling you when to stop charging.
Smartgauge is good at telling you the SoC during discharge and thus when you need to start recharging.
SG or preferably both, allow you to keep an eye on the batteries' health.
So it's both for me.
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Post by smileypete on Jan 25, 2017 10:12:53 GMT
Thanks for the comments all. I am interested in my boat electrics, my wife and children less so. I want to install something with as accurate and foolproof as possible Soc reading, sounds like the smartguage. But I will probably look to install a BMV in the fullness of time to satisfy my own interests (not sure budget will allow it straight away...) An ammeter comes into it's own when doing a FULL charge, as the Smartgauge can be a bit inaccurate at end of charge. A handheld 'clamp' ammeter that reads DC amps can be be a help here, and can be very handy for diagnosing a failing batt. Though for routine use it's not as convenient as a panel ammeter. Good to hear you're interested in the electrical side of things, one thing that helps with batts is to understand how a FULL charge is done in terms of correct charge voltage (compensated for temperature) and sufficiently low 'tail' current. For batts in regular daily use, a FULL charge at least weekly should help ensure decent performance and avoid the dreaded sulphation. For off grid liveaboard the Trojan type batts give best price/performance, but need higher than normal charge voltage, and occasional equalisation charge at even higher voltages.
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Post by lollygagger on Jan 25, 2017 11:21:19 GMT
I find it strange that the market doesn't have a monitor that does it all. Surely in this day and age it must be possible for some sort of gadget to work out the actual capacity of a battery based on voltage and discharged ah.
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