Log In | Register
Skip to main content
Topic: Smart gauge Battery Monitory (Read 21 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.
Smart gauge Battery Monitory
Yahoo Message Number: 152614
I would like to hear from anyone that has the Balmar SmartGauge battery monitor and what have been your experiences.

I know Andy has had one for a few months, but I haven't read a followup on what his present thoughts were on the SmartGauge.

Is it a better mouse trap than the Xantrex or Victron or just different??

SD Bob
2000 MB
Re: Smart gauge Battery Monitory
Reply #1 –
Yahoo Message Number: 152616
"I would like to hear from anyone that has the Balmar SmartGauge battery monitor and what have been your experiences.
 Is it a better mouse trap than the Xantrex or Victron or just different??"

SD Bob

Other than Andy, I doubt if you will find anyone here using . They are rare and not widely used or distributed in the US. You would find more users in the boating forums.
After reading the available literature and talking with Andy about the Smart Gauge, it is much different than a Link or Victron.

Xantrex Links and Victrons are amp-hour meters that measure the inflow and outflow of amperage into the coach battery. They keep a running tally of used amp-hours. The batty capacity is programed in the meter, along with the  Peukert's number (an efficiency adjustment for power lost during charging and discharging).
They have no ability to detect changes in capacity as the battery ages.
Many find the amp-hour gauge's various readouts,  monitoring voltage, amperage charge or discharge, as well so the used or remaining capacity, to be very valuable information.
To compensate the amp-hour meter's inability to determine loss of capacity, I annually derate our LD's battery capacity by 7%. That works out to loosing half the batteries capacity by 7 years, abut as long as a set of batteries will last under good conditions.
In more extreme environments, an annual derating of 10% is better.
. The Smart gauge reads percentage of charge capacity but does not measure amp-hours used. It is capable of  determining the percentage of capacity while not calculating capacity. It has the ability to accurately show percentage of capacity, even as the battery ages and looses capacity.
It does not have a readout for amperage at all.
The Smart Meter is a recent device with limited internet information or reviews available. Balmar is an old, established marine equipment company, so it should have good factory support.

So, IMO, both gauges have their advantages and neither is perfect.
For most, amp-hour meter is probably more useful, if you like to know how the system is operating as well as how much estimated battery capacity is available.
For those who do not actively monitoring the various parts of the their 12-volt system but do want to know how much battery they have available, the Smart Gauge is straight forward and as simple as it gets.

If you want to know as much as possible, having both an amp-hour meter and a Smart Meter give a broad range of information and the ability to see fairly accurate percentage of capacity.
It is a heavy hit on the wallet to have both, that's the cost of information.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: SmartGauge battery monitor
Reply #3 –
Yahoo Message Number: 152642
In short, I agree with most of what Larry said. But for what it's worth, here's my experience with the Balmar SmartGauge over the past few months. I have both the SmartGauge and a Victron BMV-700 monitor, which is similar to the popular LinkLite/LinkPro "amp counter" meters, so I'm in a position to compare the two. The obvious questions are "Which is better?", and "How accurate is the SmartGauge?"

To the first question, I can only say that despite both products being battery monitors, they do different jobs, and each has its unique benefits. I like having both, but that's a big chunk of cash (about $500).

And how accurate is the SmartGauge? It's hard to be certain, because I have no objective standard against which to compare it. I can't do the kind of exhaustive capacity testing that 'MaineSail' (the marine electrician who wrote a comprehensive review of the  SmartGauge) did, and there's no other way to know a battery's state of charge with certainty. So I pretty much believe what the SmartGauge tells me, but it's more on faith than anything else.
 I will say that it seems more "conservative" than my Victron BMV-700 amp-counter gauge--that is, when charging, the SmartGauge takes longer to reach 100% indicated state of charge. (The abovementioned review comments on this**, so it's not just me.) On the other hand, when discharging, the two gauges track reasonably closely.
 Much of my faith in the SmartGauge rests on MaineSail's finding that it continuously learns a battery bank's characteristics even as the batteries lose capacity over time--unlike amp-counter meters such as the LinkLite and my Victron BMV-700.

I intend to reprogram my BMV-700's "bank capacity" setting annually, revising it downward so that it tracks the SmartGauge as closely as possible... but I'll continue to depend on the SmartGauge as my primary monitoring device.

Now, if you only have an amp-hour counter, you can reprogram its "bank capacity" setting every year, reducing it by 5%-10% each time to approximate the loss in capacity as your batteries age. But the key word here is "approximate." This procedure is better than nothing, and will help reduce the monitor's inevitable loss of accuracy as your batteries age, but it can never be really accurate.

And--this is a problem that's rarely discussed--if you install an amp-counter meter with a set of batteries that are already a few years old, you really have no way of knowing what their true capacity is, so the initial setup of the meter is pure guesswork. Yes, you know that they started out at 225 amp-hours (for most Lazy Dazes), so you could try subtracting 10% per year and programming in the resulting number as your initial bank capacity... but their true capacity could vary widely from what that simple calculation yields, depending upon many factors--how heavily you used the batteries, how often you charged them, whether you kept them watered, etc. In short, you'll be starting out with a less than accurate meter, and it's only going to get worse as time goes by.

This is the big shortcoming of amp-hour counters: they're only as accurate as the bank capacity setting, and that's a hard number to measure without laboratory equipment. On the plus side, they do give you an accurate measure of how much power is flowing into or out of a battery bank at any given moment. That's a very useful thing to know, and it's something the SmartGauge can't tell you.
 The unfortunate fact is that neither type of gauge is sufficient by itself. As mentioned, the amp counters slowly drift out of accuracy as batteries age, giving more and more falsely optimistic readings as time goes by. That has bitten me more than once, before I realized what was going on. This is where the SmartGauge excels: it isn't mislead by battery aging.
 On the other hand, the SmartGauge can't tell you how much power you're gaining or losing right this second, so it can't be used to check the power consumption of lights and appliances, or to see how much juice your solar system is actually putting into the batteries after subtracting the various loads you're running. For that, you need an amp-counter meter with a shunt.
 In short, if you really want a good handle on your batteries, you need both gauges. But to buy both costs close to five hundred bucks. Needless to say, you could buy several sets of new batteries for that price. Personally, I like to know what's going on--especially since battery power is crucial when boondocking, as I have been for most of the past year--so for me the investment is worth it. But it's not for everyone.

What the world needs is a really well-designed battery gauge that combines the SmartGauge's intelligence and learning capability with the amp-counter's up-to-the-second information on power usage... and it needs to sell for under $200. Maybe someday... :-)

Finally, it should be noted that according to MaineSail's review, the SmartGauge doesn't work with lithium batteries, Apparently their discharge curve is so flat that it just can't get a handle on their state of charge using its thousands-of-voltage-checks-per-second method.

Andy Baird
 ** "The [SmartGauge] was lining up with my two Ah counters, once the banks were well calibrated to the Ah counters (arghh what a process), to under a 2% - 3% variance. In many cases the SmartGauge... found the [state of charge] of the used batteries faster than I could doing actual physical 20 hour capacity tests. Truly amazing.
 "I did see the SmartGauge get a bit confused when the bank was being charged. It can't really track the capacity of a battery charger now can it...? However we are only talking about 10-12% variation from the Ah counters during charging, and not a huge deal when you consider how simple this battery monitoring unit is. Another issue with tracking SOC during charging is charge efficiency variations so it was much easier to do this testing on the discharge side of the equation.
 "As soon as the charge source was discontinued, the SmartGauge fairly quickly identified the accurate SOC of the bank again, and was back within approx 2% - 3% of the two painstakingly calibrated Ah counters."
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: SmartGauge battery monitor
Reply #4 –
Yahoo Message Number: 152654
Thanks to both Andy and Larry for their replies.  A lot of good stuff here.

SD Bob
2000 MB
Re: Smart gauge Battery Monitory
Reply #5 –
Yahoo Message Number: 157428
Just the information I have been searching for. I am overhauling a '92, and the batteries, charger/converter is next. Solar will follow. This helps a lot, so thanks!
Paul
'92 Mid Bath
Re: Smart gauge Battery Monitory
Reply #6 –
Yahoo Message Number: 157431
Reviewing this thread on the SmartGauge, I want to make a couple of corrections.

On May 7th, 2015 I wrote, "I can't do the kind of exhaustive capacity testing that 'MaineSail' (the marine electrician who wrote a comprehensive review of the  SmartGauge) did, and there's no other way to know a battery's state of charge with certainty." That's wrong. There's no other good way to determine a battery's capacity, but its state of charge can be determined by looking at its resting-state voltage.

To do this, the battery has to have been sitting for at least four to twelve hours (it depends on which expert you consult) with no power flowing into or out of it--no charging from any source, and no lights, appliances, or other loads in use. Then you can measure the voltage and use a chart such as Table 1 on this Trojan web page to determine its state of charge. (Check with the battery manufacturer for the appropriate chart for your batteries--for example, AGM batteries are different.) Or if it's a flooded-cell battery, you could use an accurate hydrometer to measure the state of charge of each cell, and then average them together.

Unfortunately, when traveling neither method is very practical, since most of us are almost always using our electrical systems. If it's ten o'clock in the evening and you want to know whether you have enough power left to stay up and watch a movie, you probably don't want to turn off all the lights for four hours, or go suck acid out of your batteries, just so you can find out. That's what a battery monitor is for.

Second, someone commented that the SmartGauge is a new product. It's new to the US, but has been in use in the UK, where it was invented, for more than ten years. Balmar is just the US distributor. If you're interested in how it works, there's a detailed description here, and there's a comparison between SmartGauge and amp-hour counters such as the LinkPro and Victron BMV-700 here.

In the nine months since I last posted about the SmartGauge, I've found little to add to my comments back in May. The SmartGauge and Victron BMV-700 amp counter track each other loosely, with the SmartGauge usually being more pessimistic--so I rely on it more than on the BMV-700.

Twice the SmartGauge has shown sudden drops in displayed charge state that didn't match up with my power usage at the time. In one case I reset it, and in the other I left it alone and it recovered over the next couple of days. Then again, the BMV-700, like any amp-hour counter, has sometimes shown unrealistically high charge states, and I've had to adjust its battery bank capacity setting once to compensate for aging of my batteries--a normal procedure.

In short, neither device is perfect, but then no battery monitor is--the quirky nature of battery chemistry makes that a difficult goal to attain. I still think if I had to have only one battery monitor, I'd pick the SmartGauge.

Andy Baird
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Smart gauge Battery Monitory
Reply #7 –
Yahoo Message Number: 157432
"It's new to the US, but has been in use in the UK, where it was invented, for more than ten years."
 Imagine that. The British at the cutting edge of electrics battery monitoring. It must have started with Dr. Lucas. I'm glad my LD Refrigerator wasn't invented by him. I don't like warm beer.

I like my Blue Sky battery monitor.

bobmoore14