Balmar SG-200 Battery Monitor

[sailah]

Originally Posted by witzgall

Often new flooded batteries can take many cycles before they test up to their rated capacity, assuming they are quality batteries. Of course I cannot say for sure if that is the case in your installation.

Chris

Thanks Chris, and I have not cycled them "many" times other than down to say 95% SoC. I guess I will need to be patient and see what happens.

All batteries are Duracell from Batteries Plus with very new date codes. I assume they are quality batteries, I think they are rebranded East Penn which are well-regarded.

[Maine Sail]

Originally Posted by sailah

My question is more along the lines of why isn't my SoH reading higher than 100% on brand new GC2s. Mine are Duracell and date codes are 3/2019.

1- New flooded lead acid deep cycle batteries take many cycles to reach their full Ah rating. They can also be destroyed, due to sulfation, before this ever happens.

2- The SG200 will take a fair number of deep cycles before it can more accurately calculate the SoH.

3- Many flooded batteries we have tested never cycle up to "rated capacity". Most AGM & GEL batteries do, or at least get very close, but with typical flooded batteries we see some rather wide discrepancies. We actually scrapped a whole article on PSoC cycling abuse with flooded batteries for Practical Sailor because we could not get the majority of the flooded batteries to achieve their rated capacity.

Originally Posted by sailah

I've drawn the bank down to 56% once, and other times to mid 90s %. But I really haven't drawn it down/cycled like I would when I would cruise.

You actually need to use your batteries before the SG200 will give you a good SoH calculation. This is a learning algorithm battery monitor meaning it needs to "learn" the behavior of your bank.

Originally Posted by sailah

My suspicion is that I haven't cycled it enough for the SG200 to learn, just wanted to hear others experience.

Bingo.. And if you don't ever see 100% SoH this is not odd at all, it is what it is....

[sailah]

Originally Posted by Maine Sail

You actually need to use your batteries before the SG200 will give you a good SoH calculation. This is a learning algorithm battery monitor meaning it needs to "learn" the behavior of your bank.



Bingo.. And if you don't ever see 100% SoH this is not odd at all, it is what it is....

Thanks Rod, very helpful.

[john61ct]

Originally Posted by sailah

My question is more along the lines of why isn't my SoH reading higher than 100% on brand new GC2s. Mine are Duracell and date codes are 3/2019.

..

My suspicion is that I haven't cycled it enough for the SG200 to learn, just wanted to hear others experience.

Well you're the pioneer here I think and thank you.

SoH is going to be much more of a challenge to get accurate than SoC.

My understanding is dozens of cycles may be required, and the wider the SoC range the more useful each cycle is.

Also, as mentioned, new lead batts are not yet at full capacity, even in normal use actually deep cycling that can take a few months.

Have you run them through their commissioning cycles yet? If not, you should ideally get a baseline 20-hour capacity test done at the same time, very similar protocols.

[john61ct]

Originally Posted by sailah

All batteries are Duracell from Batteries Plus with very new date codes. I assume they are quality batteries, I think they are rebranded East Penn which are well-regarded.

Yes, best value in the world most likely.

Rolls / Surrette may last a lot longer, but the up-front investment is a lot higher, just the delivery may cost more than the Deka's all up 8-)

[sailah]

Originally Posted by john61ct

Well you're the pioneer here I think and thank you.

SoH is going to be much more of a challenge to get accurate than SoC.

My understanding is dozens of cycles may be required, and the wider the SoC range the more useful each cycle is.

Also, as mentioned, new lead batts are not yet at full capacity, even in normal use actually deep cycling that can take a few months.

Have you run them through their commissioning cycles yet? If not, you should ideally get a baseline 20-hour capacity test done at the same time, very similar protocols.

I don't know about pioneer, I leave that mantle to the pros like Maine Sail.

I haven't done anything other than install the batteries and the SG200. I rewired the entire boat (also thanks to Maine Sail's awesome ACR schematic).

With scheduled splash on Saturday, I have been working at a feverish clip so the batteries will have to fend for themselves. Not even sure what a commissioning cycle is, if it's reasonable I'll do it.

[john61ct]

Originally Posted by two-rocks

Similar situation, minus the shore power (50w solar to keep things topped up until the other 300w go back up).



My FLA batteries are 8+ years old and show 90% SOH. Cycled similar to you.



Going to wait until a few consecutive deep cycles (launch this Friday).



Hope it is not accurate - lithium batteries were the next project ;-)

Well of course LFP has no need at all to get to Full as lead requires, at least 2-3 cycles a week.

That's a pretty good run for your FLA, why are you saying you hope 90% SOH is not accurate?

And thanks for reporting in here, every data point helps!

[john61ct]

Originally Posted by Maine Sail

if you don't ever see 100% SoH this is not odd at all, it is what it is....

After a long thorough learning time has passed, in theory that should self-adjust right?

Or should we occasionally manually reset Full at the right charge current taper point to help the process?

Along the same lines, if we do get an accurate 20-hour load test performed, I assume adjusting that data point would be useful to the meter?

Finally, that FLA vs AGM Ah rating issue is very interesting, thanks! But why did that lead to difficulties with quantifying for the SoH effects of PSOC abuse?

[Paul L]

So we have/had amp counting monitors that got a bad name because typical users could not distingush between a valid 100% SOC and one due to early reset by the device. Now we have the SG200 which gives SOH percentages that the user can not know if they are a valid or not. As I have said multiple times here, the unit should have an indication if it has sufficient learning to give a valid reading within the stated specs or not.

[john61ct]

And again, exactly what more-accurate standard measurement could it compare its estimate to, in order to judge its own estimate is now "accurate enough"?

If you want that, you need to rent or borrow a unit that you know is more accurate (likely would not fit on your boat), and benchmark the SG200's estimate against that.

[Maine Sail]

Originally Posted by john61ct

After a long thorough learning time has passed, in theory that should self-adjust right?

Or should we occasionally manually reset Full at the right charge current taper point to help the process?

Why would it? If your battery has a "rated" capacity of 100Ah, and that is what you program in, and the best the battery can muster is 88% of that why should it ever read 100% SoH. There are a lot of batteries out there that do not meet spec and will never deliver 100% of their labeled rating. We see them through our shop routinely.

Originally Posted by john61ct

Along the same lines, if we do get an accurate 20-hour load test performed, I assume adjusting that data point would be useful to the meter?

How is an owner going to figure out a new 20 hour rating? This will involve a number of complete discharges, at controlled temp and at constant current to 10.5V. You may get lucky and land on the 20 hour load by cycle 2, but most likely not.

If you adjust the data point to your now current capacity, in an attempt to wind up with a SoH of 100%, but the battery is not at 100% SoH, this this is a false economy.

Unfortunately batteries sit in hot warehouses, trailers, distribution centers, shelves of retailers etc. and self discharge. They can be sulfate damaged before you even get your hands on them. Some manufacturers don't even bother to run a 20 hour test (usually flooded automotive group size batteries) and instead try to mathematically calculate the 20 hour rating from an RC test.

Originally Posted by john61ct

Finally, that FLA vs AGM Ah rating issue is very interesting, thanks! But why did that lead to difficulties with quantifying for the SoH effects of PSOC abuse?

Well, it's kind of hard to run any sort of controlled study pairing brand A to brand B for PSoC suitability when only one or two of the batteries in the test group will deliver what their rating is. Garbage in = garbage out.

After burning huge hours, messing with batteries that don't meet & can't deliver their "rated capacity", you finally throw in the towel and call it a day.

[Paul L]

Originally Posted by john61ct

And again, exactly what more-accurate standard measurement could it compare its estimate to, in order to judge its own estimate is now "accurate enough"?

If you want that, you need to rent or borrow a unit that you know is more accurate (likely would not fit on your boat), and benchmark the SG200's estimate against that.

And again, the unit's "learning" algorthim should be able to determine if it has enough information to offer valid data. It is not reasonable to have the experts or tech support just respond with the unit is really accurate you just haven't let it learn enough, with zero definition of what enough is. The benchmark would be the accuracy specification that the vendor states.

[john61ct]

Breaking in lead batteries properly, including initial "commissioning charging" is critical to getting max longevity, and as noted, will often increase their capacity.

This process for lead banks does involve a very similar process to load testing, and done properly, and infrequently over the bank's lifetime, neither causes any damage.

But yes, capacity will likely further rise **after** the breaking in period, so do a 20-hour test before and after, and use the higher Ah result as your benchmark for comparison later on.

If not done then, your test must be compared to the mfg rating, which with quality makers in the US, is the 20-hour AH rating, but often not accurate, as MS points out too optimistic.

Obviously the other specs are for a different purposes, so IMO just ignore them.

_______
protocol:

The first few dozen cycles, go easy, avoid high current rate discharges **and** charges.

First step, really fully charge, as per mfg spec endAmps,*

then, manually follow mfg equalizing instructions, if applicable.

Then discharge at .05C (5A per 100AH) for about 20 hours, but **stop discharging before** 10.5V.

This discharge cut off voltage is by definition SoC 0%, and **much** lower than what should be ever be used in normal cycling.

But do not believe anyone claiming such maintenance routines are as "harmful" as the usual routine abuse from user ignorance.

It **would** be harmful to let the battery sit at such low SoC, so immediately as possible after that 10.5V is reached, start recharging, ideally at a slow rate, ~.15C or lower

Such slow charging should continue for the rest of the break-in period, say two months if regularly cycling, or 50 cycles over time, trying to avoid huge draw currents as well.

http://www.amplepower.com/primer/break-in/index.html

https://www.catalina36.org/comment/51915#comment-51915

http://www.sailnet.com/forums/showthread.php?p=3779746

_______
load testing for SoH / 20-hour residual capacity

Note this procedure is similar to the above, so that they could be done in conjunction with each other.

This one is just more precise, requires maintaining the load at a constant as possible current rate as SoC and voltage drops.

CTRL-F search for

20 hour capacity

At MS's site here*https://marinehowto.com/programming-a-battery-monitor

Better yet, read it all, and check out the rest of the site.

[two-rocks]

Originally Posted by john61ct

That's a pretty good run for your FLA, why are you saying you hope 90% SOH is not accurate?

And thanks for reporting in here, every data point helps!

Makes replacement easier to justify - i.e. I'm hoping the reading rates the bettery at <70% SOH once it gets a few fill ups and full 'downs' If not, I'll just use them like I stole them

[john61ct]

Originally Posted by Maine Sail

Why would it? If your battery has a "rated" capacity of 100Ah, and that is what you program in, and the best the battery can muster is 88% of that why should it ever read 100% SoH

To me, the SoC percentage should reflect the actual current capacity of the bank.

That is the goal implied in your three BM articles on marinehowto, right?

Isn't that how SmartGauge operates? without any Ah capacity input from the owner.

And, as with most BMs, there is the ability to reset the 100% point when the owner knows the bank is Full via measuring tapering endAmps.

Even if SG200's automatic SoH estimating will reduce the required frequency of (or in theory even eliminate) that requirement for accuracy (in my sense), are you saying it does not offer that feature?


> How is an owner going to figure out a new 20 hour rating?

If they don't have the gear and skills to do so, they could pay someone like you to do it.

I concede we are discussing a high level of care here, what most owners consider unrealistic or not worthwhile in practice.

But let's just say, for the sake of science. . .