Alternator not regulating charge

[Mike OReilly]

Originally Posted by kmacdonald

You still have the use of it. It won't hurt the batteries enough to make a difference. Negligible if any harm IMHO unless you run it for weeks or months non-stop.

Well, I’m a big fan of doing nothing , so maybe I will just leave it alone. We don’t tend to run the engine long, but there have been a few occasions when we’ve had to motor for many hours, or even up to a day. This happened last season, and the batteries still seem OK, so maybe I’m fretting about nothing.

Originally Posted by belizesailor

If your batteries are already at a high SOC from solar/wind then yes the regulator should raise V and lower current. Thats normal.

Check manufacture's spec for V set points. Note that max V varies with battery temp. Does your regulator have a temp sensor?

Thanks for the assurance, and the info. I have no temp sensor for any of the chargers. I have four different ones: alternator, shore power charger, solar, wind. I’ve looked, and can’t find any info on these Magnacharge batteries. Has anyone heard of them? They seem OK, but I really wish I could get at the electrolyte.

[belizesailor]

Originally Posted by Mike OReilly

Well, I’m a big fan of doing nothing , so maybe I will just leave it alone. We don’t tend to run the engine long, but there have been a few occasions when we’ve had to motor for many hours, or even up to a day. This happened last season, and the batteries still seem OK, so maybe I’m fretting about nothing.



Thanks for the assurance, and the info. I have no temp sensor for any of the chargers. I have four different ones: alternator, shore power charger, solar, wind. I’ve looked, and can’t find any info on these Magnacharge batteries. Has anyone heard of them? They seem OK, but I really wish I could get at the electrolyte.

Some of those chargers/regulators likely support battery temp sense. Its a good thing to have...better charge at colder temps and avoid baking batteries at higher temps.

[kmacdonald]

I wouldn't worry about temp sensors unless you have very high current charger in the tropics. Just feel the batteries after motoring for a while and see if they are hot. I doubt they will be. Try feeling them after 30 minutes when they have been receiving a lot of charge current also. I bet they won't be hot or even warm.

[kmacdonald]

This is what MaineSail says about charge voltage:
If you’re not charging deep-cycle flooded batteries at 14.6V (bare minimum) to 15.0V, for PSOC use (boats, RV’s or off-grid solar), they’re simply not getting properly charged. Even many AGM batteries are capable of being charged as high as 14.7V and their health is vastly improved by doing so. With all that said, use your battery manufactures recommended voltages but stick to the maximum of the safe-range not the low side. For example if your battery maker suggests an absorption setting of 14.4V to 14.8V you’ll want to be at 14.8V end of the spectrum not at the 14.4V end.

[Stu Jackson]

Originally Posted by kmacdonald

I wouldn't worry about temp sensors unless you have very high current charger in the tropics. Just feel the batteries after motoring for a while and see if they are hot. I doubt they will be. Try feeling them after 30 minutes when they have been receiving a lot of charge current also. I bet they won't be hot or even warm.

kmac, the way Mike describes his use, his solar & wind keep him full. Therefore, when he starts his engine, his bank will never have "...been receiving a lot of charge current..." from the alternator. Ever.



Mike, your plan is good: either do nothing or, having learned how to, lower the V to 14.4 like your solar controller. You don't use your engine much, and even if you did, when you do run it, either of two things happen: 1) it doesn't run long and your bank is full anyway; 2) it does run a long time, but your bank is full anyway.


There will be little current from the alternator because the battery acceptance when they are full is very low.


It might not take you 200 years to learn this stuff, it will only feel like it! A perfect example of "Ask me how I know..."


I think you've seen this already, but noodle around some, it's where I picked up a lot of good info:


Electrical Systems 101

[Viking Sailor]

Mike,



It looks like you have a Volvo engine. Three Volvo that I have worked on all had key start switch. After starting the switch springs to the left leaving the alternator operating. The next switch position to the left shuts down the alternator.



You may be able to turn off the alternator as needed.



Good luck...

[Old_Geezer]

Sounds like it's working to me. My 115 Merc outboard charges at 14.6 according to my depth sounder.

[desodave]

I had to research Magnacharge after finding a sealed battery in my brother in law's garage after he had passed. I didn't find the website particularly helpful - Home - but there's lots of distributors who may be able to help you more, inc one in Thunder Bay - you're from Winterpeg aren't you?

[sailorboy1]

Better to be a little undercharged than boiled out for sealed batteries. Can “fix” the undercharged.

[Mike OReilly]

Originally Posted by desodave

I had to research Magnacharge after finding a sealed battery in my brother in law's garage after he had passed. I didn't find the website particularly helpful - Home - but there's lots of distributors who may be able to help you more, inc one in Thunder Bay - you're from Winterpeg aren't you?

Thanks for this. Yes, I found the website, but very little useful information. A dealer is probably a good idea, although they aren’t always as knowledgable as one would hope.

To be honest, they’ve been find batteries so far. They’ve taken a few beatings and appear to keep bouncing back OK. I keep them in plastic boxes, so I think I’d see the residue of any boil overs. So far, nothing. But I really dislike not being able to check the fluid levels.

I used to live in Thunder Bay. Now I live where the boat is; which is currently in Corner Brook, NL.

Originally Posted by sailorboy1

Better to be a little undercharged than boiled out for sealed batteries. Can “fix” the undercharged.

I’m inclined to agree with you .

[john61ct]

Transpo (not tempo?) make a voltage manual-adjustable VR, I think about $80?

Not fancy staged, but better than the fixed voltage ones.

[Mike OReilly]

Originally Posted by john61ct

Transpo (not tempo?) make a voltage manual-adjustable VR, I think about $80?

Not fancy staged, but better than the fixed voltage ones.

Says “Transpo” on the regulator. I dunno…?

[john61ct]

Yes bog standard OEM for dozens of companies.

Just some were talking "tempo" above. . .

Amazon and eBay both have them, 911-02R

[a64pilot]

So, how does it adjust voltage? You said it was adjustable.
A potentiometer?

Without trying to put words in Maine Sails mouth, I believe his point is that with very few exceptions, batteries rarely get fully charged, and by pushing the voltages he’s trying to get them charged.
I think for an AGM 14.8 May be a little high, and may over time harm them as in dry out the electrolyte.
However if you don’t motor for many, many hours, it likely isn’t bad for them.
If the adjustment is easy, then consider it if your going on a long motor run.

[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