battery question

Micahbigsur@msn.com · Posted: Sat Nov 09, 2019 12:41 pm Post subject:

I just read an article that better explains why the smart gauges I have had never seemed to work as well as they should have for me. Batteries are constantly changing internally as they charge and discharge and a lot of computing power goes into updating the changes it measures to give accurate readings. The meters have to reset when the batteries reach 100% each time for the current internal state of the batteries, if the charge doesn't reach 100% over time accuracy starts to drift. Since I often ran for days off solar and wind charge cycles might not have reached full often enough and I'm sure using 3 discrete and different forms of charging could have confused the meters even more.

Micahbigsur@msn.com · Posted: Sat Nov 09, 2019 12:51 pm Post subject:

I am going to order the new Balmar smartgauge that only reads volts and state of charge using battery capacitance. It doesn't show any amp hour info. I will put up a review of how it works out vs. my volt meter over time as I won't have to worry about interpreting surface charge.

thataway · Posted: Sat Nov 09, 2019 9:41 pm Post subject:

ssobol · Posted: Sun Nov 10, 2019 2:57 am Post subject:

Micahbigsur@msn.com · Posted: Sun Nov 10, 2019 1:18 pm Post subject:

Bob, as I have said before, my 2 previous smart gauges with stunts never seemed any better than my (experienced, not saying it would work for anyone else) interpretation of a voltmeter, a waste of money. Now I know why, they need to gather new data for the computation by reaching full 100% charge, (as you say, rare on a small boat cruise) otherwise the results start to drift off and they become inaccurate. They don't seem to mention that before you spend your hard earned money.
The new Balmar smart gauge has a computer that interprets different battery data without a shunt, I don't need to know amps out or in, my solar readout has what I need of that. (Mine puts out up to 28 amps). The Balmar does give you true voltage (no need to "rest") and the current state of charge, these are the most useful (in my opinion) in the real world. So far the testing and reviews of this new technology are good. Since shunt gage's are basically only, effectively, just ammeters on our small boats I don't see them any more useful and in fact less useful than a good understanding of a voltmeter.
I know I am going against the current tide's love of shunt smart gages but I think they are only effective for power management on larger yachts with generators.
I am offering to be the guinea pig on the Balmar as with the wiring and fuses it will cost about $350, serious money for a new technology. After a several month winter cruise I will put up a new thred on whether I think it is worth the money vs. my interpretation of our Blue Seas digital volt meter ($42).

Micahbigsur@msn.com · Posted: Sun Nov 10, 2019 6:11 pm Post subject:

Sorry I ment to say percent of charge, not "state of charge" on the Balmar display.

Micahbigsur@msn.com · Posted: Mon Nov 11, 2019 2:03 am Post subject:

Looking back at my posts I realize I should say that my somewhat negitive opinion of Victron type shunt monitors is just based on my personal experience with them, many other very experanced boaters like them and they are the industry standard.

thataway · Posted: Mon Nov 11, 2019 9:02 am Post subject:

Here is what I see as a contradiction. As I understand it, the newer SG 200 with a shunt (2019 availability) does all which the "older" SmartgaugeTM 44 12/24 (2005 availability in the UK--a little later in the USA), but the SG 200 now is able to be accurate with the LiFePO4 batteries--which the SmartgaugeTM 44 12/24 was not able to work with. Also the newer SG 200 is cheaper, and will give a far more accurate picture when charging. (This was an area where the older unit was not as accurate).

A good article to read is by Rod Collins, Compass Marine. This is about the original SmartgaugeTM 44-12/24. He now sells the SG 200 which he claims is superior to the original. This is a guy who has done extensive testing and feels that the SG 200 is better than the original

While visiting the web site, if youhave time, and are interested he has a great article on LiFePO4 batteries. (He has been using them for a number of years.)
Rod Collins, is an ABYC certified electrical technician, and is on the standards committee of ABYC. He also manufactures some electrical components.

You pays your money, and makes your choice. But why not pay less and get more? Today, I would buy the Smartgauge SG200 over any of the Columb (Amp Hour) meters. However the installation is critical. Also the Victron 702 etc are all good, if you realize the limitations, and are willing to re-calibrate. I don't have the SG200, because it was not available when I put in my second battery system. It is now. I would purchase from the site above--it is $220--comperable to all of the others within a few dollars.

Micahbigsur@msn.com · Posted: Mon Nov 11, 2019 10:14 am Post subject:

I am still not convinced that any shunt system will work out that well in the ACR interconnected multi-charged system that I put together. I could easily be wrong, and the Balmar with a shunt could work differently than other monitors. I think the typical monitors are too complex and I want a simpler system that just gives me what I want, volts and particularly % of charge, that's all I need to self monitor my house batteries, especially since I had to go back to the old flooded batteries (Suzuki charge system) that are more tolerant of abuse. I have been perfectly happy monitoring my batteries with the voltmeter and experienced judgement using a % of charge chart on my phone. If this Balmar equals my judgment process it will save some time and it will also be easier for Dana. The LiFePo4s need a DC to DC charger added to the already complex system that seems a bit much even for me at this point as it would still have to utilize a flooded start battery....but next year....? I know a lot of you guys know more about electronics than I do, I am a jack of all trades, master of none.
I guess I am a sucker for trying something "new" and simpler, we will see how this Balmar stacks up.

journey on · Posted: Mon Nov 11, 2019 12:26 pm Post subject:

Bob, I'm confused and I'd like some help.

First of all, I understand that there are 2 types of battery meters behind discussed, both Balmar: an SG200 and a Smartguage. One uses a shunt, measuring amps in and out. The other has no shunt but uses some algorithm to give % SOC. Am I correct?

Second the article by Russ Collins concerns the Balmar Smartgauge, which he now proclaims to be the gold standard, saying that shunt type meters do not give a true SOC but the Smartgauge does.

How can you compare the two and install a shunt meter? Is there some factor one can use to make the two types equivalent? I do understand that the Balmar Smartgauge is new and needs some history.

Boris

thataway · Posted: Mon Nov 11, 2019 3:27 pm Post subject:

Boris,
Here is the way I understand it. The "SmartgaugeTM 44 12/24" was patented in about 2005 by an English Company. Balmar became the licensed distributer for the US. Lithium battery technology has such a flat discharge curve, the SmartgaugeTM 44 12/24 was not at all accurate. CDI/Balmar developed a new gauge which would read the lithium as well as carbon foam, lead acid, and AGM etc. There was a second problem with the original SmartgaugeTM, and that was when being charged, was also not accurate, but was shortly after the charging was complete.

By adding a shunt, and modifying the program, the SG 200 retains the 'intelligence" of the original gauge, but adds in the ability to be accurate with LiFePO4 batteries and when all batteries are charging. It also gives "state of health"--which compares to a "new" battery, as well as State of Charge. Balmar SG 200 won IBEX 2018 Innovation award a year ago. It was generally available in the US the first part of this year. Read the articles to see what else it can or cannot do.

As to what technology the SmartgaugeTM and the SG200 use--that remains a secret.

What Rod Collins says in this article on the SG 200

journey on · Posted: Mon Nov 11, 2019 4:03 pm Post subject:

Thanks, Bob. I was under the impression that the Balmer SG200 was a different way of getting SOC with a shunt.

Instead, it appears that the Balmar SG200 is a further development of the Balmar Smartgauge, using a "smart shunt" to additionally give SOH and current in/out. And also working with LiFePO4 batteries, which you have and I don't.

Hope I interpreted everything correctly.

Boris

ssobol · Posted: Mon Nov 11, 2019 5:24 pm Post subject:

The Balmar SG200 uses a shunt like the Victron units. The difference is that the Balmar SG200 is allegedly smarter than the Victron and automatically corrects for battery condition as the battery ages.

Supposedly the problem with the Victron type units is that if the operator does not periodically update the settings based on battery condition, the accuracy of the readings degrade over time.

The SG200 is that it is meant for house battery banks. The manual says

Micahbigsur@msn.com · Posted: Mon Nov 11, 2019 5:32 pm Post subject:

I just hope after this discussion that the non shunt Balmar that I ordered will give me what I have always wanted: a simple easy to use no brainer voltage and % of charge reading on my conventional house battery bank. I don't need anything more, just K.I.S.S. (I am the SS of course)
Thanks all.