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john61ct · 12-09-2018, 18:19

Mike OReilly · 13-09-2018, 03:32

Quote:

Originally Posted by Capt.Don

Mike, Not to change the topic too much, when we first bought our boat, I was monitoring the batteries by voltage. I even made a label with the 50% discharge voltages, etc. Since then, I installed a Victron BMV battery monitor. Instead of watching volts, I can watch Amps and Amp-Hours. I had similar questions why my 70Amp alternator would only put out 50Amps. Still learning, but with more instrumentation. Something to think about,
Don

I have a Victron BMV. I think my self-inflicted wound here is that I’ve always monitored amp and amp-hrs when looking at how the alternator was doing — when I looked at it at all, which wasn’t very often. For some reason I never really noticed where the voltage was set. Then, I noticed — and forgot about looking at the current, which caused me to be concerned.

I’ve been doing other stuff, but still plan to lower the voltage setting a little. In general, I don’t motor for long periods. But there was one occasion last season where we motored for nearly 24 hrs. The batteries all seem fine, so if I damaged them I can’t tell. But b/c they are sealed wet-cells (never, ever buy sealed!), I can’t confirm the electrolyte levels.

Anyway, it has all be very interesting. And I’ve learned a little bit more about all this electrical stuff. So, thank you all.

john61ct · 13-09-2018, 03:55

Wet cell is a confusing term.

Best to use FLA/flooded vs SLA/sealed.

Technically AGM could be considered wet, in contrast to GEL, even though both types are SLA / VRLA.

And I agree that FLA is best unless special circumstances require one of the SLA types.

Mike OReilly · 13-09-2018, 03:59

Quote:

Originally Posted by john61ct

Wet cell is a confusing term.

Best to use FLA/flooded vs SLA/sealed.

Technically AGM could be considered wet, in contrast to GEL, even though both types are SLA / VRLA.

And I agree that FLA is best unless special circumstances require one of the SLA types.

See … I keep learning

.

sailorboy1 · 13-09-2018, 04:25

Quote:

Originally Posted by Mike OReilly

See … I keep learning

.

Your batteries sound ok. Just goes to show that this CF constant battery obsession thing is just mostly a way to cause you to lose your hair

Mike OReilly · 13-09-2018, 07:28

Quote:

Originally Posted by sailorboy1

Your batteries sound ok. Just goes to show that this CF constant battery obsession thing is just mostly a way to cause you to lose your hair

Come to think of it, I have lost a lot of hair since joining CF — So that’s what happened

.

Hugh17 · 17-09-2018, 08:27

[QUOTE=sailorboy1;2716293]

Quote:

Originally Posted by Mike OReilly

SB: When you say “go with it”, I assume you don’t mean just leave the alternator pumping at 14.8 v all the time? I do have LFA batts, but I wouldn’t want to leave it running at full bore for more than an hour.

I did mean that. I have my alternator set to stay at 14.8v for 6 hours. Been that way for years and never hurt the batteries. Before I changed to the 6 hours I had it at 1 hour, batteries neve4 really got charged if I motored a l9ng time.

I’ve watched my battery acceptance for years now. From -80ah n the morning it will take 5-6 motors of motoring to really get charged. The only down side is you may have to water the batteries more often (I use about 2 cups for m6 4 every 1.5 months)

But if you have a sealed start battery etc you need to isolate that or it will cook

This is good to know. I've also noticed that my alternator is putting out over 14 volts whenever running, even if motor sailing for many hours a day. I've been concerned about overcharging the batteries. The marine mechanic who rebuilt the alternator told me not to be concerned about it. However, I'm concerned about anything I don't fully understand, and alternators are one of those things.

curtis742 · 19-09-2018, 06:10

Quote:

Originally Posted by kenbo

Mike,

Your regulator is fine and working properly. That model of Transpo regulator is just like an internal voltage regulator. It allows the alternator to put out as much current as possible until the vSet is reached, in your case that's 14.8v. Then is just tapers the field current to hold that voltage indefinitely. With FLA batteries that's OK, just add water when necessary.

Very common regulator in HD trucks and it looks loke you have a truck alternator as well. That's a 4" J mount you have. It ain't broke don't fix it!

Ken

You are one of the few who is absolutely correct. Most alternators run at ~14.5 volts and vary the current accordingly to maintain this operating voltage. I would also check this voltage at the battery with a known good DVOM with the solar disabled. Solar chargers do vary the voltage and are considerably higher in the bulk charge phase and far higher during the equalize function. Solar chargers do taper off the voltage, alternators do not.

GaryBode · 19-09-2018, 06:18

Your alternator is always going to put out voltage when your engine is running. When the engine is off it will read battery voltage. Since you have voltage you should be looking at amperage. If it is ok then what is your concern?

curtis742 · 19-09-2018, 06:35

Quote:

Originally Posted by Mike OReilly

Three years now. They seem fine, but I haven’t done a proper 20 hr test or anything. Assuming the alternator/regulator has always been operating like this (and I just never noticed

), I’ve not seen any issues with the batteries.

It just seems a high voltage for hours and hours. But clearly I don’t know much about this stuff...

Severely depleted batteries will show a lower voltage and as they are charging the voltage will slowly climb until the batteries are fully charged. At this point you should see 14.5- 14.8 volts. Since you have solar also you should equalize 3-4 times a year to remove the build up of sulfate on the plates. This process will push the battery voltage to over 16 volts for 2-3 hours. The most common failure of batteries is a slow sulfate build up during normal use. The sulfate formation progressively gets worse to the point of coating the plates and inhibits electron transfer between the plates causing weak cells
The weak cells will drain the remaining cell to their voltage causing additional sulfation on all cells in a cascading failure. The newer pulse chargers help remove this sulfate and provide quite a bit longer battery life. I recently brought back 18 out of 20 Trojan L16 batteries in my solar bank using an industrial pulsetech battery recovery unit. Still working on the last two.

john61ct · 19-09-2018, 07:40

Quote:

Originally Posted by curtis742

Solar chargers do taper off the voltage, alternators do not.

Alternators fitted with stock VRs do not.

All it takes is money and the will to fix the problem

if the owner thinks the cost / benefit calculation works out for their unique situation

Mike OReilly · 19-09-2018, 07:59

Uhm, thank guys, but I’ve got this sorted. Carry on if you like. Maybe others will come to the thread and learn stuff (as I have

). But just know, I’m good now.

john61ct · 19-09-2018, 08:49

Quote:

Originally Posted by curtis742

you should equalize 3-4 times a year

Not just solar, any PSOC context, and lots more frequently than that.

IMO monthly should be default even when well coddled.

Some situations weekly is called for.

Have to follow the mfg protocol, each is different.

It's a preventative not a cure.

> The newer pulse chargers help remove this sulfate and provide quite a bit longer battery life.

No, marketing snake oil.

Only reliable cheap way to gauge State of Health is a 20-hour load test.

Batteries below 70-80% remaining capacity should be replaced with new for anything critical.