Smartgauge vs Mastervolt Easyview-5 vs Simarine Pico

[Brav]

Originally Posted by Paul L

Kind of a mix of units here. What does the Victron''s 3.7 hrs left translate to in %SOC?

You don't have to translate.. but I am not sure why Bruce says he can't read the rest. On my BMV 702, I just hit the down arrow, and give you SOC, Ah consumed, live current draw, etc etc. Not sure why that info isnt available here

[john61ct]

My understanding is formal testing of the monitors hasn't started, Bruce just showing off the setup.

Patience, I'm sure he'll give a full detailed report all in good time.

[ayates]

Originally Posted by conachair

Don't suppose Smartgauge will be releasing their code for the masses of makers to incorporate into arduinos & ESP's any time soon..

To me, this is one of the biggest drawbacks of Smartgauge. There are no options for adding a repeater display or logging the measurements. There appears to be a port on the circuit board, but their technical support would not give me any details on it


Allan.

[OceanPlanet]

Originally Posted by john61ct

And I suppose just a little less wear & tear if 20-hour load tests are run say quarterly towards EOL.

How about for LiFePO4? Big prismatics, not the little ones, e.g. CALB 180fi, or whatever cell your Lithionics use.

I know it depends on the discharge rate, so let's say 20-hour .05C.

It would be too dangerous to actually hit 3.00Vpc right? Would staying above 3.05 be OK?

Assuming you immediately put a low-rate charge on from there back to say 3.2V before resuming regular charging.

What is the regular-usage cutoff for the Lithionics BMS?

Sorry to have been MIA, we've been swamped.

Note that on our test bench we're using FF or other Pb, no Li.

To answer your question about the Lithionics cutoff, the "RVC" (Reserve voltage Cutoff) is when the voltage goes below 12.4/24.8/49.6 for over 30sec. This leaves 10-15% of total capacity left in the bank. The reserve can be accessed by pressing the BMS "Reset" button, however recharging should be done ASAP. At the next cutoff (LVC: 11.2/22.4/44.8) is when both charge & discharge sides get cut off to prevent going any lower.

See attached.

However, this is getting off the topic of monitoring...sorry for the sidetrack.

[OceanPlanet]

Originally Posted by Brav

You don't have to translate.. but I am not sure why Bruce says he can't read the rest. On my BMV 702, I just hit the down arrow, and give you SOC, Ah consumed, live current draw, etc etc. Not sure why that info isnt available here

The SOC % accuracy of the Victron is cut & dried....it is a matter of how accurately it is programmed. It just simply does the math...the AH's used subtracted from the programmed-in battery capacity. So, you do need to know, and program in the REAL capacity...not what's on the label, or what it was years ago when you first put in the batteries. You need to do actual capacity testing to see what you really have. At least once a year.

[OceanPlanet]

Originally Posted by john61ct

My understanding is formal testing of the monitors hasn't started, Bruce just showing off the setup.

Patience, I'm sure he'll give a full detailed report all in good time.

Yes, patience, thanks! We've actually been doing quite a bit of testing, however want to give the mfg's the chance to complete & send firmware updates to fix issues we've discovered, before we nail them to the wall.

Let's just say that none of them are perfect...;-)

[john61ct]

You guys really are performing a tremendous service to the industry!

Keep it up, and take your time 8-)

[Maine Sail]

Originally Posted by OceanPlanet

The SOC % accuracy of the Victron is cut & dried....it is a matter of how accurately it is programmed. It just simply does the math...the AH's used subtracted from the programmed-in battery capacity. So, you do need to know, and program in the REAL capacity...not what's on the label, or what it was years ago when you first put in the batteries. You need to do actual capacity testing to see what you really have. At least once a year.

Actually on the count down the Victron is cut & dry using math at 1:1 meaning 1 Ah discharged = -1Ah on the display. However, on the count back up (charging), it subtracts for programmed Coulombic efficiency.

If you have it set for 90% CEF when you recharge it will only count back 9Ah's for every 10Ah's delivered to the battery. This is all well and good if the battery is 90% efficient, it has an accurate Ah capacity programmed in and we complete a full 100% recharge on every cycle. Problem is that on boats we don't operate batteries this way. If we PSOC cycle the CEF will throw the counter off within just a few cycles and the counting error will keep growing until a 100% SOC reset occurs..

Unfortunately Coulombic efficiency is not linear, it varies throughout the SOC curve, but the counter treats it as if it is linear.

The problem with a single number Coulombic efficiency is that bulk is upwards of 98%+ efficient and in the high 90's, as %SOC, you're looking in the range of 50% charge efficiencies. Thus when you PSOC cycle, like we do on boats, or do a few shallow cycles, there is no way for it to remain tracking accurately using a single number efficiency factor..

It is not full recharge cycling (50% to 100% to 50% to 100%) that throws an Ah counter like the Victron for a loop but rather PSOC cycling & a single number charge efficiency (50% to 80% to 50% to 80% etc. etc.) that skews them SOC accuracy wise.

[OceanPlanet]

Originally Posted by Maine Sail

Actually on the count down the Victron is cut & dry using math at 1:1 meaning 1 Ah discharged = -1Ah on the display. However, on the count back up (charging), it subtracts for programmed Coulombic efficiency.

If you have it set for 90% CEF when you recharge it will only count back 9Ah's for every 10Ah's delivered to the battery. This is all well and good if the battery is 90% efficient, it has an accurate Ah capacity programmed in and we complete a full 100% recharge on every cycle. Problem is that on boats we don't operate batteries this way. If we PSOC cycle the CEF will throw the counter off within just a few cycles and the counting error will keep growing until a 100% SOC reset occurs..

Unfortunately Coulombic efficiency is not linear, it varies throughout the SOC curve, but the counter treats it as if it is linear.

The problem with a single number Coulombic efficiency is that bulk is upwards of 98%+ efficient and in the high 90's, as %SOC, you're looking in the range of 50% charge efficiencies. Thus when you PSOC cycle, like we do on boats, or do a few shallow cycles, there is no way for it to remain tracking accurately using a single number efficiency factor..

It is not full recharge cycling (50% to 100% to 50% to 100%) that throws an Ah counter like the Victron for a loop but rather PSOC cycling & a single number charge efficiency (50% to 80% to 50% to 80% etc. etc.) that skews them SOC accuracy wise.

So true. FWIW, in our Firefly cycle testing we kept getting a "blip" at the end of the SOC curve (tracked on our Victron VRM portal) where it wasn't counting enough AH's back in, and then suddenly jumping to 100% when the charged parameters were met. So we kept raising the CEF which reduced the sudden blip. That is, the graphed SOC curve accuracy improved with each raising of the CEF. I think we got up to 97%(!)

However, Coulombic efficiency isn't "true" efficiency...as the Ah's back in are at higher voltage than the Ah's out...so the true Watt hour efficiency is much lower that the Coulombic efficiency.

[john61ct]

Well I strive for a system that does get you back to 100% Full very frequently, if not every time. For bank longevity, more accurate SoC is just icing on the cake.

So which SoC meters overcome the "Single number CEF" problem?

Is auto-calculating CEF the answer? Assuming usage patterns are pretty consistent. Which monitors do that? (other than SmartGauge)

[OceanPlanet]

Originally Posted by john61ct

Well I strive for a system that does get you back to 100% Full very frequently, if not every time. For bank longevity, more accurate SoC is just icing on the cake.

So which SoC meters overcome the "Single number CEF" problem?

Is auto-calculating CEF the answer? Assuming usage patterns are pretty consistent. Which monitors do that? (other than SmartGauge)

Going off my memory
(Jack, my test bench guy will be making a list of all this stuff):
Victron: you put in the CEF, it doesn't change it.
Philippi: you put in a CEF as a starting point, and it updates it somehow.
Mastervolt Easyview: I forget! Need to ask Jack...
Simarine: Can't input....it needs some cycles to calculate CEF

[a64pilot]

Originally Posted by john61ct

Well I strive for a system that does get you back to 100% Full very frequently, if not every time. For bank longevity, more accurate SoC is just icing on the cake. )

Unless I misunderstand, this is not a difficult goal. It’s simply a matter or dropping into float when the correct charge current is reached.
If you have a bus bar and can connect all the negatives to it, then connect a shunt between the bank and this bus bar, then it’s child’s play to measure the total current flow into or out of the bank.
I have my Magnum MS 2812 programmed to drop into float when charge voltage at absorption voltage reaches .5% of my banks rating, which is correct for my Lifeline bank.
My Solar I just leave at absorption voltage, cause I’m learning things with this shunt, like I can get to high 90’s% charge in four hours or less, but to get to completely 100% charged takes pretty much seven, the last few percent dribble in slower than I would have thought, even after hearing many times how slow it is, seeing is believing.

[CatNewBee]

I dont care much about SOC percentage at all. I want to know the exact Ah used, the current load A and the cell or block Voltage. All this other guess work is meaningless to me, the percentage does not give me any benefit regarding the state of the battery and ageing, also time left to recharge is a stupid reading on the mastershunt, as soon as you turn on some load, it becomes obsolete.

When you know how many Ah you have and how many has been used, you are better off and can make educated decissions.

[john61ct]

Originally Posted by a64pilot

Unless I misunderstand, this is not a difficult goal.

It is for boats that

rarely access shore power, and
whose only charge source is limited solar, and
regularly use more per day than is available to recharge

Which is more likely with lead banks, with its falling absorption.

Also those who may have dino juice sources but prefer not to run them often

Or don't know the "trick" of running them before the solar day starts, no way of estimating SoC accurately etc.

[Zven]

Is there any update from OceanPlanet? Or from Noelex?
I thought this was a great thread so far, as battery monitoring is important and not many good solutions are available for boaters who care about the gritty details.
Those Pico units sure look cute, but the proof is in the eating, as they say.
Keep up the good work, and please post your results if at all possible :-)