Balmar vs Blue Sea

[dwedeking2]

I'm redoing my electrical system. I'm looking at two system monitors and am curious if anyone has any direct experience feedback on either.

Balmar Smart Gauge Monitor - Smartgauge Battery Monitor | Balmar
Blue Sea Vessel Systems Monitor - https://www.bluesea.com/products/180...onitor_VSM_422

The Blue Sea one is a little more $$ but also includes tank monitoring. I'm not really one of those "engineering nerds" who wants to know if I used 2 ah more today than yesterday, but rather just want to be able to accurately keep on top of things and be forewarned of any issues.

[BozSail]

Read the article in the link below. The writer (MaineSail) is very well regarded when it comes to electrical issues. Based mainly on this article, I purchased the Balmar Smartguage and find it very useful (and simple), as it tells me what I need to know - and can understand. The SOC (state of charge) on my house battery bank is very useful information.

Smart Gauge Battery Monitoring Unit Photo Gallery by Compass Marine How To at pbase.com

[john61ct]

In looking at the Blue Sea unit's docs, this looks like a traditional coulomb-counting SoC gauge, requires the user to guesstimate and manually update the bank's AH capacity as it declines over time.

It is also likely necessary to periodically reset/calibrate the 100% setpoint.

All in all, the SmartGauge unit is IMO much more likely to be usefully accurate over time, when the bank is at rest apparently within 2-3%.

Be aware while charging that accuracy may go down to around 5%.

There is also a "SmartBank" combiner/isolator unit that can work together with the SmartGauge.

[dwedeking2]

Originally Posted by john61ct

In looking at the Blue Sea unit's docs, this looks like a traditional coulomb-counting SoC gauge, requires the user to guesstimate and manually update the bank's AH capacity as it declines over time.

It is also likely necessary to periodically reset/calibrate the 100% setpoint.

All in all, the SmartGauge unit is IMO much more likely to be usefully accurate over time, when the bank is at rest apparently within 2-3%.

Be aware while charging that accuracy may go down to around 5%.

There is also a "SmartBank" combiner/isolator unit that can work together with the SmartGauge.

John,

Thanks that was the feedback I needed.

Boz,

I've read most of Maine Sails write ups and had originally figured on the Balmar but then stumbled upon the Blue Sea system as I'm building my build out list. You're correct his write ups are really good.

[john61ct]

Blue Seas generally makes great products, this unit may be better than the usual shunt-based coulomb-counter.

Apparently some of the modern ones can automatically tie in to BMS for auto-resetting at 100% SoC, but I haven't heard of any that can track declining AH capacity over time, which I believe SmartGauge does as part of its internal algorithms.

But it certainly is an area where many would welcome more detailed info.

I'm particularly interested in a comparison with the more advanced/recent units Merlin's developed, presumably with ​Chris Gibson's help, I think he still has a tech/advisory position with them?

Plus a discussion of SoC measurement of LFP banks in a DIY context. . .

[boatbod]

The two items listed use very very different technology. Blue Seas VSM is a shunt based monitor, whereas the Balmar uses two wire electronic sensing (transconductance?).

Best do plenty of research first.

[john61ct]

wrt SmartGauge, Maine Sail's detailed findings linked to above, plus the EnerSys white paper are plenty AFAIC.

[jheldatksuedu]

I almost bought a used Balmar unit last week, I actually did but the guy I bought it from couldn't find the unit in his piles of stuff, so refunded the money. I'm glad to see this and happy to know I need to do more research, thanks all for the input.

[Jeanneau 45.2]

I purchased a Smart Gauge last year from Maine Sail. Seems that what you are paying for is a sophisticated sensing algorithm as the actual hardware is rather underwhelming. For example, the battery ring terminals supplied by Balmar are, let's just say marginal, which while a minor cost issue is rather pathetic given the "top shelf" price. All-in-all I am satisfied ... easy to understand and useful for managing the battery bank SOC .... but as a "black box" device accuracy is hard to confirm. In the end, I relied on Maine Sail's recommendation.

[a64pilot]

Originally Posted by Jeanneau 45.2

I purchased a Smart Gauge last year from Maine Sail. Seems that what you are paying for is a sophisticated sensing algorithm as the actual hardware is rather underwhelming. For example, the battery ring terminals supplied by Balmar are, let's just say marginal, which while a minor cost issue is rather pathetic given the "top shelf" price. All-in-all I am satisfied ... easy to understand and useful for managing the battery bank SOC .... but as a "black box" device accuracy is hard to confirm. In the end, I relied on Maine Sail's recommendation.

I second your opinion, the strength of the Smart Gauge though is that it requires no input from you, in fact if I understand mine, the best thing I can do is to leave it alone and not mess with it as opposed to a regular battery monitor that requires constant calibration as it drifts from accuracy once calibrated

[ramblinrod]

Well, I plan to install the Blue Sea VMS.

The device packs a ton of info in exchange for very little real estate. shore
Power volts, amps, freq. DC volts (2 banks) amps, ah in,
Ah out, SOC%, monitors up to 3 tank levels (fuel, sanitation, water), and bilge pump cycles, duration.

I was considering developing a Raspbery Pi based solution but with development time, the VSM is far better value.

As far as battery monitoring goes, 2 decimal
place accuracy is simply isn't needed.

With the fridge running, 12.2Vdc as the sun is coming up, 12.8 Vdc as it sets, and all is well in the world. ;-).

[Matt Johnson]

We had the vsm 422 on our last boat and really liked it (except the SOC was always off), but decided to try the Smartgauge on the new boat. I've also added two Blue Sea 1732 ammeters to show solar/wind and outgoing power. Ended up being lower cost than the VSM and gives us the info I want.... Except for a bilge pump counter, but that's an easy add with a hobbs meter.

Matt

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