Battery voltage discharge level.

[skipgundlach]

Originally Posted by a64pilot

You have been equalizing them for weeks?

yes, for however long the sun lasts after it's actually full.

My shore charger, when I use it for a kickstart after a particularly low morning reading, gets to float and puts in no amps, whereas the sun may continue to put in a few amps, at well over 14V but not quite as high as Trojan wants them.

For all that, we're usually off the boat when it would actually reach full charge per BSC (C100), so don't know for absolute certainty that it's reached that point; in those cases we look for the S03 signifying high voltage.

But the evidence supports a surface charge, and the BSC reaching 100% frequently when we can see the gauge at the same time has suggested that the batteries are, again toast, despite some very rigorous care and feeding (plenty of water, never to the plates, and usually not taking much; when we have shore power @ 80A, sun at 30+, sometimes, and wind (with a controller which shuts it down at 14.2V), we believe we've got adequate charging.

And, in fact, before the failures our bank behaved exactly as would be expected from the anticipated loads and, in the middle months, get fully charged early in the afternoon on solar alone...

[Jeremy-KHYC]

Originally Posted by conachair

So unless you're batts are at 30C (looks like from trojans datasheet) , then a amp counter percentage capacity reading will be wrong...

You know it's a shame no one has tried to make a total health monitor for batteries. Temperature, amp counting, voltage state, fluid level and acidity should all be things easily monitored. I would wager with the right relay setup you could even engineer a periodic internal resistance measurement as a final check on lifetime. It would eliminate all this guesswork.

[john61ct]

Originally Posted by skipgundlach

Does an indicated SOC in the 30s qualify for deep discharge (overnight from essentially full)?

Qualifies as abuse IMO, will drastically shorten lifespan.

> They've been equalizing for a couple of weeks now

Equalizing is a once-off procedure that should be run manually, and precisely as per the batt mfg's spec'd protocol. Ideally from shore power.

Never just relying on a charge source's settings, nor allowed to run automatically.

On a very worn battery may take many hours, but **definitely** should not inflict that high a voltage for days and days!

What sort of batteries?

Originally Posted by skipgundlach

My shore charger, when I use it for a kickstart after a particularly low morning reading, gets to float and puts in no amps

Something seriously wrong right there, fix ASAP

> whereas the sun may continue to put in a few amps, at well over 14V but not quite as high as Trojan wants them.

ditto



> when it would actually reach full charge per BSC (C100)

what do those mean?

> we look for the S03 signifying high voltage

What is S03?

What exactly do you call "high voltage"? resting or charging or under a load?


> we believe we've got adequate charging

adequate for what?


> despite some very rigorous care and feeding

That would include getting to 100% Full as per endAmps, as quickly and as frequently as possible.

And only rarely going below 50%

> in the middle months, get fully charged early in the afternoon on solar alone

"fully charged" based on what evidence?

[conachair]

Originally Posted by Jeremy-KHYC

You know it's a shame no one has tried to make a total health monitor for batteries. Temperature, amp counting, voltage state, fluid level and acidity should all be things easily monitored. I would wager with the right relay setup you could even engineer a periodic internal resistance measurement as a final check on lifetime. It would eliminate all this guesswork.

Done it Well, not quite. Voltage, current & temperature are pretty easy with a few dollars on sensors & a raspberry pi. SG & electrolyte level bit more complicated. Plotting data is fascinating, you'll see trends hidden in the noise that you'd never pick up just looking at the numbers.

[john61ct]

Originally Posted by conachair

fuller than the BEP meter, the other night in the cooler air they seemed to tally up much better

I've never come across evidence that the BEP meter is particularly accurate.

Certainly when the bank's been at rest a while, I'd rely on the SmartGauge more.

Temperature is certainly a critical factor affecting all these variables.

[conachair]

Originally Posted by john61ct

I've never come across evidence that the BEP meter is particularly accurate.

Certainly when the bank's been at rest a while, I'd rely on the SmartGauge more.

Temperature is certainly a critical factor affecting all these variables.

From check with various other meters no evidence to show that it's too far out measuring amps in/out.

I rely on actually getting them charged most days

[john61ct]

Originally Posted by Jeremy-KHYC

You know it's a shame no one has tried to make a total health monitor for batteries

If it were easy, would have been on the market long time ago.

It would be a lot simpler if intended for use with say T-105s, or maybe Trojan FLAs in general.

But each manufacturer's products, and even between their various lines, vary in behaviour and performance, reaction to all those variables discussed above, most dramatically.

Volumes, price resistance and margins do not currently justify the huge development expense to achieve great accuracy in Ah-counting SoC meters across all the various battery types sold worldwide.

Maybe that will change as reliance on DC electric storage becomes more widespread.

Putting incentives in place so that battery manufacturers actually make **more** profits rather than less, from increasing bank longevity, I suspect would give technological progress in this arena a really big boost.

[a64pilot]

Originally Posted by conachair

So unless you're batts are at 30C (looks like from trojans datasheet) , then a amp counter percentage capacity reading will be wrong...

Yes that is correct, and it’s because your banks actual capacity changes with temp too, and it’s only that capacity if discharged at the 20 hour rate, any quicker and it’s less, very quickly discharged and it’s much less, very slowly discharged and it’s much more.

So we sort of are playing with an average, but do you really care if your 63 as opposed to 67% SOC?

A tremendous amount to this battery stuff is actually measuring with a micrometer, marking with chalk and cutting with an axe sort of thing.
Meaning that we try to be dead nuts precise, we buy fancy instrumentation that reads in single digits, but in truth can it resolve to single digits? I don’t think so, but it’s close enough.

[a64pilot]

It’s like the 50% discharge thing, a battery doesn’t go dead if discharged to less than 50%, but it’s a generally accepted number that tries to balance capacity and of course cost and weight with battery lifespan.

But there is a correlation in depth of discharge and battery life of course.

[a64pilot]

Originally Posted by skipgundlach

yes, for however long the sun lasts after it's actually full.



My shore charger, when I use it for a kickstart after a particularly low morning reading, gets to float and puts in no amps, whereas the sun may continue to put in a few amps, at well over 14V but not quite as high as Trojan wants them.



For all that, we're usually off the boat when it would actually reach full charge per BSC (C100), so don't know for absolute certainty that it's reached that point; in those cases we look for the S03 signifying high voltage.



But the evidence supports a surface charge, and the BSC reaching 100% frequently when we can see the gauge at the same time has suggested that the batteries are, again toast, despite some very rigorous care and feeding (plenty of water, never to the plates, and usually not taking much; when we have shore power @ 80A, sun at 30+, sometimes, and wind (with a controller which shuts it down at 14.2V), we believe we've got adequate charging.



And, in fact, before the failures our bank behaved exactly as would be expected from the anticipated loads and, in the middle months, get fully charged early in the afternoon on solar alone...

I don’t think you have equalized them, not in my opinion, equalizing requires of course them to be totally 100% charged to begin with and then rested for some time, then hit with a steady equalization voltage and held there for the specified time.

All that pretty much requires a continuous power supply, which means either hours and hours of generator or shore power, in my opinion.

Anyway, I’d make sure contacts are clean, fully charge them, take specific gravity readings which should point out any problems, then equalize IAW the manufacturer’s protocol and then take specific gravity readings again to see if there is a difference.

[conachair]

Originally Posted by a64pilot

So we sort of are playing with an average, but do you really care if your 63 as opposed to 67% SOC?

Not that interested so long as they are actually getting fully charged often, but was hoping that comparing the smart gauge SOC with amps out would be a helpful indication of capacity - looks like it isn't going to tell much without some calibration against temperature & some kind soul to spend weeks with lab equipment checking if it actually tells you anything useful.

[skipgundlach]

Sigh...

I'll attempt answering the many items in the quote, IN the quote, with bold italics...

Originally Posted by john61ct

Qualifies as abuse IMO, will drastically shorten lifespan.

> They've been equalizing for a couple of weeks now

Equalizing is a once-off procedure that should be run manually, and precisely as per the batt mfg's spec'd protocol. Ideally from shore power.

Never just relying on a charge source's settings, nor allowed to run automatically.

On a very worn battery may take many hours, but **definitely** should not inflict that high a voltage for days and days!

What sort of batteries?

Trojan L16H-AC, as specifed in the beginning.

Extended and multiple equalization specifically from my Trojan (factory) rep, with whom I've been in contact since the second and third bad-cell failures now almost a year ago.

And not days and days as in continuous. Rather, multiple iterations, per day, and only via solar, which means only after they're full and floated.

I'd guess at 7-8 instances of 1-3 (mostly 1) hour equalizations in that time (since the rep told me to do just that).


Something seriously wrong right there, fix ASAP

No argument, here, other than wondering, exactly what IS wrong. Our charging system was engineered and reviewed by a marine electrician. One of the original 4 batteries had a bad cell ON INSTALLATION. Two more failed - bad cell again - closely together within the 2-year warranty period. Then a 4th, a couple of months ago. We reduced our load by setting the freezer to only provide refrigeration. We took out the bad-cell pair and operated on two less-than-a-year old batteries. Both of them have nearly identical SGR, other than one cell being 010 lower than the other...

Trojan is going to do an autopsy on the last of the bad-cell batteries; it's beyond believable coincidence that the entire new bank could, over time, fail in the same way.

> whereas the sun may continue to put in a few amps, at well over 14V but not quite as high as Trojan wants them.

ditto



> when it would actually reach full charge per BSC (C100)

what do those mean?

> we look for the S03 signifying high voltage

What is S03?

Both are references to how the BSCharger reads/delivers information.

C100 is generally accepted as fully charged.

E03 is error #3 signifying high voltage (I forget above which it is that the BSC doesn't register, but that's the message you get when it's exceeded - yet our solar charger is incapable of delivering the right volts for equalization, so it does the best it can.

What exactly do you call "high voltage"? resting or charging or under a load?

There were a variety of places that might have come up, but high in the sense of equalization would be 15.2, I think, but the solar charger can only deliver 14.8, so it's not even very vigorous equalization.

As to the resting/charging/under load, I referenced 13.5V, which was after charging but with no charge input (and for that matter, next to no output either as the master switch was OFF), but the BSC reading 97% and the SGR suggesting something in the low 80% (I don't have the trojan chart on this laptop).


> we believe we've got adequate charging

adequate for what?

for what's needed to charge a nominal 870AH bank, now 435 nominal with half of it out.


> despite some very rigorous care and feeding

That would include getting to 100% Full as per endAmps, as quickly and as frequently as possible.

And only rarely going below 50%

Until all the excitement, it was rare to get to 80%, and full (BSC=C100) well before the end of the day. Typical use was about 60AH (typical SOC in the 90s in the AM) overnight until the 4th of 4 batteries had a bad cell, noted by the difficulty in charging after it had happened and confirmed by an SGR which showed that the FIRST bad-cell battery was absolutely stellar - and, 4 months after being taken out of the circuit, it STILL reads 6.2V.

> in the middle months, get fully charged early in the afternoon on solar alone

"fully charged" based on what evidence?

The TM2020 showing positive net (CAH) and a days-since-charged of 0.00, and the BSC showing 100% for an extended period of time, along with a 13.5V reading...
\

I don't have a clue whether I or Trojan is behind these failures, but I've corrected all that anyone with a clue has been able to say MIGHT be a mistake as well as vastly improved my ability to charge (see upgrade in CF) via solar, and, now, via inverter-charger AND a controller on my wind generator.

FWIW, the Trojan rep has seen pix of the installation and is satisfied with my connections (all 2-0, hydraulically crimped and heavy glue heat-shrunk), and charge mechanisms.

I record the details of every bit of information every time I pass the meters - which generally amounts to many to a dozen or more records per day. Reviewing prior performance is therefore easy, and I can clearly see when the problems occurred (not there now so can't cite actual date and detail).

So far as I can tell, while we use a fair amount of amphours (freezer and reefer averages - when the bank is all 4 - 12A full time), we also previously had no issues about recovery per day.

Yet, here we are.

[john61ct]

>> what do those mean?

I mean, literally never heard of "BSCharger" , please link to it, ideally a datasheet or manual.

Same with C100, I only know that as a C-rate discharge current, 0.01C, much lower than the usual 20-hour rate.

[john61ct]

At this point, I'd stop listening to that Trojan rep, or anyone in a customer-facing position,

develop a relationship by phone/email to an engineer-level as high up in the food chain as possible back at HQ.

And Trojan itself as a maker has IMO been dropping a notch or two itself, maybe cutting corners in recent years, excessively cashing in on that stellar reputation? Over-hyped marketing department for sure. . .

> Our charging system was engineered and reviewed by a marine electrician

Of course competence varies, put energy into finding one respected by people like Maine Sail, Bruce @PlanetOcean, or at least the long-term old yard guys around wherever you are.

[john61ct]

> our solar charger is incapable of delivering the right volts for equalization, so it does the best it can

Which means you are not equalizing, and must use another charge source in order to do so.

Assuming that you are indeed ever even getting to 100% Full; the only measure of that you should be using at this point is as per endAmps:

do not stop (drop to Float) before current accepted drops to 0.005C, half an amp per 100Ah capacity.

So 435Ah (if that in reality) means endAmps of around 2A.

Use a **known-accurate** ammeter***at the bank post** so you know when to stop, do not rely on any charge sources or distant shunts.