NextStep2 regulator bulk charge issue

[john61ct]

No. And not newish, easily possible they're murdered.

Point of a good shore charger is known good source to compare what happens on the alt.

But now it's clear IMO you need to do a proper 20-hour test, if below 80% of rated AH, toss and replace.

Then with known-good batteries, use a known good charger to set a benchmark.

Then work on the alt.

[mitiempo]

Originally Posted by jackt

Do you think I should immediately bring up to full with shore charger, or try alternator with longer abs? Did you see my table of tests?

I wouldn't worry about the alternator as long as the voltages (absorption and float) are accurate and the alt outputs reasonable current when running at speed. It is very rare to fully charge a battery bank with an alternator of any size as it really takes 6 to 8 hours. After all you have a sailboat and the only time they would be completely full is when motoring all day.

Also as a marina kept boat the AC powered charger is more critical for battery life.

[jackt]

Originally Posted by john61ct

But now it's clear IMO you need to do a proper 20-hour test, if below 80% of rated AH, toss and replace.

So that means a constant load of 464/20 = 23.2 A?? That's a huge load. I wouldn't even have that. Is there another way? Or does one split into two banks - 232/20 = 11.6 A - maybe with lots of lights on. And then what?

[john61ct]

Do each battery separately. Not a big load, some light bulbs will do it. Just time and attention.

https://forums.sailboatowners.com//i.../#post-1295253

automating with smartphone

​http://www.cruisersforum.com/forums/....php?p=2386436

google "maine-sail 20-hour test" for more howto's.

[jackt]

Originally Posted by john61ct

Do each battery separately. Not a big load, some light bulbs will do it. Just time and attention.

So with 4 x 6V 232 Ah batts = 464 Ah, you mean do two tests - each with TWO batts in series. Don't see how to test each of 4 batts separately with 12V lights.

https://forums.sailboatowners.com//i.../#post-1295253

>automating with smartphone

​Absorbtion Time for AGMs - Page 7 - Cruisers & Sailing Forums

Good idea.

>google "maine-sail 20-hour test" for more howto's.

Will do.

The temp thing is impt?? That means a heater blower. It's about 60-40F here.

I never did drive my new (4 yr old) batts to less than about 12.2V so hopefully they are not too bad.

[jackt]

Originally Posted by john61ct

Do each battery separately. Not a big load, some light bulbs will do it. Just time and attention.

https://forums.sailboatowners.com//i.../#post-1295253

automating with smartphone

​Absorbtion Time for AGMs - Page 7 - Cruisers & Sailing Forums

google "maine-sail 20-hour test" for more howto's.

I recharged last w/e using the shore charger. Took 6 hrs (or more after I retired). By morning they were "fully charged" (float is triggered at current < 7.5A).

Have not done any 20-hr test yet (not sure when yet as it will require extended planning).

After a few amp hours draw I then did a charge using the motor alternator NS2. It seemed to work as expected with absorption amps rapidly decreasing to just 1 or 2. I had abs time set to just 10 mins and amps were 1 or 2 by then. Normally abs would be longer of course. But now I am somewhat confused...

Q1. If batts are fully charged, what happens if abs is set to 14.7V and abs time is set to 2 or 3 hours - if amps are low (eg, <5) but absorption time limit has not been reached (2-3 hr), will the batts be damaged by high 14.7V? They are getting 14.7V for 2-3 hours but at low amps. Is the 2-3 hrs of absorption - continuous high volts (low amps) - a problem for a fully charged battery? This would happen if motorsailing (or running a fridge etc).

Q2. I followed normal shore charger bulk-abs-float mode with a "recondition" mode to try to equalize, which is supposed to be:

"Constant current (0.3-7.5A) for 4 hours limited to 16.0V"

But for 3 hrs I did not see anything higher than 14.4V during recond mode. Amps seemed to be held at 7.5A. Is there a reason that recon would not go any higher than 14.4V?

There is a recondition mode for CALCIUM batts (only) which is similar:
"Constant current (2.5-7.5A) up to 16.0V then hold for 1 hr or 12 hour timeout"
I applied this to my calcium starter batter and it did show 16V. They also overflowed some acid through the tiny vent holes in the caps!?

Maybe I could apply calcium mode to my 6V batts to get a proper 16V equalization out of them?

[jackt]

If batts are fully charged, what happens if abs is set to 14.7V and abs time is set to 2 or 3 hours - if amps are low (eg, <5) but absorption time limit has not been reached (2-3 hr), will the batts be damaged by the high 14.7V? They are FULL and still getting 14.7V for 2-3 hours but at low amps. Is the 2-3 hrs of absorption - continuous high volts (low amps) - a problem for a fully charged battery? This would happen if motorsailing (or running a fridge etc).

[mitiempo]

Originally Posted by jackt

If batts are fully charged, what happens if abs is set to 14.7V and abs time is set to 2 or 3 hours - if amps are low (eg, <5) but absorption time limit has not been reached (2-3 hr), will the batts be damaged by the high 14.7V? They are FULL and still getting 14.7V for 2-3 hours but at low amps. Is the 2-3 hrs of absorption - continuous high volts (low amps) - a problem for a fully charged battery? This would happen if motorsailing (or running a fridge etc).

They won't be damaged. Batteries will only take the current they need. If flooded they will possibly lose a bit of fluid.

[john61ct]

Yes nice thing about FLA, bit of gassing no worries, just replace the water lost.

But if you were storing them on say a solar setup **with no loads** at all, you'd remove the minimum time forced absorb every morning, let them float.

A fridge running with no charge source would take enough to well justify absorb every morning.

It's tough to get timed absorb just right unless your load pattern is predictable, better to use charge sources that let you adjust endAmps.

[jackt]

Originally Posted by mitiempo

They won't be damaged. Batteries will only take the current they need. If flooded they will possibly lose a bit of fluid.

It's confusing to me because in an earlier remark from someone I recall it was stated that it's high volts that matters and can damage, not high current. So if I have to motorsail with fully charged batts and a 2-hr timed absorption phase, there will be a bit of gassing only but not any damage? Okay.

[jackt]

>Yes nice thing about FLA, bit of gassing no worries, just replace the water lost.

ok.

>But if you were storing them on say a solar setup **with no loads** at all, you'd remove the minimum time forced absorb every morning, let them float.
A fridge running with no charge source would take enough to well justify absorb every morning.

ok.

>It's tough to get timed absorb just right unless your load pattern is predictable, better to use charge sources that let you adjust end Amps.

Sure. In the past 1 hr abs worker for me with batt monitor claiming they were full (amps clocked back to 1-2).

I don't have a reg (NS2) that allows adjustment of end amps, just abs time. Shore charger flips from abs 14.7V to float (13.7) at 7.5A.

[john61ct]

7.5A is what % AH?

[jackt]

Originally Posted by john61ct

7.5A is what % AH?

It's a fixed setting for trip to float on a Projecta 50A charger. As my bank is nominally 464 Ah and 2% would be 9.2A, it's fairly close. But it's more than 1%, 4.6A.