No big battery chargers?

[Kenomac]

Originally Posted by Exile

I don't think you're missing anything. I haven't crunched the numbers for myself, but it seems the general consensus I've been reading for years is that using a generator or engine solely to get batts. from 80/85 to 100% is not economical. The variables can change when you're also running your engine for propulsion obviously, or using the genset to make water, run 110v appliances, etc. The economies may also change if you have an expensive AGM bank which is less tolerant of not getting fully recharged.

Fwiw, my WB 8kw burns closer to 0.5gph.

I think our Westerbeke 10kw only burns around .25 gph

[Exile]

Originally Posted by Kenomac

I think our Westerbeke 10kw only burns around .25 gph

You know, I've heard others commenting to that effect. Like the OP, I need to track that better and find out with more certainty.

[Exile]

Originally Posted by Kenomac

Wow, lots of wrong info on this thread. Little Harbor 46, Nice Boat!

BIGGER is BETTER when it comes to charging. We increased our 50am charger to 125amps by adding a second Mastervolt unit, the batteries now charge up much faster.

I think what people are saying is that adding charging capacity only speeds up charging in the bulk phase, i.e. 50-85%. Not much charging capacity needed in the absorption phase, i.e. 85-100%, and having more can't hurt but doesn't help. Hence the utility of solar/wind/etc., or a64's suggestion of an efficient suitcase generator for that last phase.

But I'm sure someone will correct me if I'm wrong!

[Stu Jackson]

Originally Posted by Exile

I think what people are saying is that adding charging capacity only speeds up charging in the bulk phase, i.e. 50-85%. Not much charging capacity needed in the absorption phase, i.e. 85-100%, and having more can't hurt but doesn't help. Hence the utility of solar/wind/etc., or a64's suggestion of an efficient suitcase generator for that last phase.

But I'm sure someone will correct me if I'm wrong!

IIRC, a64 has repeatedly said he uses the generator in the morning to get as much in at bulk with its higher acceptance and uses the solar after bulk is finished.


I think you got it backwards.


But ya did ask, right?

[jr_spyder]

Originally Posted by Stu Jackson

It has been interesting, and you probably understand that you're reinventing the wheel.

Maybe more like discovering this particular wheel for the first time. I have to admit, with some humility maybe, that although I've read book chapters, articles, and battery documents aplenty regarding charging and best battery practices it never really all clicked. Being on this forum with real guys with real boats with genuine usage experience actually makes it all click. Of course the fact that I'm sailing a lot more now off the grid (finally living the dream) makes an issue like this far more important to me, so time to really understand it.

[Exile]

Originally Posted by Stu Jackson

IIRC, a64 has repeatedly said he uses the generator in the morning to get as much in at bulk with its higher acceptance and uses the solar after bulk is finished.


I think you got it backwards.


But ya did ask, right?

I thought a64's morning generator run was via his diesel generator, but then I vaguely recall he may not have one. In that case I may have gotten it backwards. That's why I like these threads!

On the other hand . . . for boats with large diesel generators & appropriately sized battery chargers, but no solar/wind/etc., wouldn't it be more efficient to run the small suitcase generator for the 6-8 hours it takes to get from 85-100%? a64 said this burns more like 0.9g of gasoline vs. the potential 3-4g(?) of diesel for a 6-8 hour run. I thought this was what he was speaking to but maybe I misunderstood.

Totally agree, btw, with the utility & cost-effectiveness of adding solar, etc., especially for those with AGMs. In my case, I just haven't been away from the dock & shore power enough as of yet to justify.

[Exile]

Originally Posted by jr_spyder

Of course the fact that I'm sailing a lot more now off the grid (finally living the dream) makes an issue like this far more important to me, so time to really understand it.

An important point! I think it's difficult for those of us who really haven't started living our dreams to make it all click. I can understand it to a large degree theoretically, but I'm sure priorities change once you're out there in ways that aren't all that obvious to those who haven't yet left.

[Stu Jackson]

Originally Posted by jr_spyder

Maybe more like discovering this particular wheel for the first time.>>>>>>>>>>>>>>>>

A worthy point, especially when coupled with the "now it affects me" syndrome.


But please understand that while most of the folks who visit this and other boating forums are here to share, there exists a certain sense of frustration - at least on my part ! - about some of these basics.


Of course, if never exposed to the basics at all, it's new to you. Understandable.


But part of us old geezer's (my?) disappointment comes from the fact that there is now the internet. From 1987 to 1998 I had a single battery outboard powered 25 foot sailboat and admittedly knew nothing about boat electrics, even though I read some books. When we bought this boat in '98 I learned, read some more, bought Calder's Boatowners Manual and learned and learned and learned.



Book learning and putting it into practice are I think what you're saying here.


But I just typed in a search for "deep cycle battery charging" and got lots of results. And refining that search on type of battery would get more info.


Point is, though, that the internet simply didn't exist back when many of us old timers were learning this stuff. So I chose to learn and share.


Of course, there will always be new folks willing to learn, and not everyone has the inherent or learned ability to absorb this tedious engineering carp!


So thanks for getting me to think about this more deeply. You make a very good point.


PS - One possible "solution" to avoiding reinventing the wheel is to "hang out" on a few boating forums in, this particular case, electrical sections of those forums. I believe that within a week one could quickly learn who the "trusted contributors" are and would find that a handful of boating electrical website links have tons of information, like these two:



Maine Sail's https://marinehowto.com/


Electrical Systems 101 Electrical Systems 101

[a64pilot]

Originally Posted by Exile

I thought a64's morning generator run was via his diesel generator, but then I vaguely recall he may not have one. In that case I may have gotten it backwards. That's why I like these threads!



On the other hand . . . for boats with large diesel generators & appropriately sized battery chargers, but no solar/wind/etc., wouldn't it be more efficient to run the small suitcase generator for the 6-8 hours it takes to get from 85-100%? a64 said this burns more like 0.9g of gasoline vs. the potential 3-4g(?) of diesel for a 6-8 hour run. I thought this was what he was speaking to but maybe I misunderstood.



Totally agree, btw, with the utility & cost-effectiveness of adding solar, etc., especially for those with AGMs. In my case, I just haven't been away from the dock & shore power enough as of yet to justify.

I do have a Diesel generator, but hate to use it when the Honda will do the job, to be clear it’s the hours I hate to put on the Diesel, plus it’s a bear to service, not really all that hard, just the Honda is so easy to service.

Anyway as I usually start charging when we are at least 75% SOC my bulk time at 100 amps charge rate is really short, maybe 5 min or so?
So while I could crank the Diesel and charge at 185 amps with both chargers, my bank due to its high state of charge to begin with, wouldn’t accept the 185 amps, there would be zero bulk time.
So the Diesel and both chargers wouldn’t do anything that the Honda and one charger turned down to 100 amps won’t do.

Just throwing numbers around but assume a $2400 bank every other year is of course $100 a month, and that’s enough money for me to try to make that bank last years longer.
That’s a high number, but it was chosen intentionally to make nice even numbers, however the concept is the same.
My bank is 6 of these and yes you can get cheaper than Amazon of course but $2,400 isn’t far off.


Anyway if you deeply discharge an AGM bank and if you believe Lifeline knows what they are talking about, then the bigger the charger the better to extend the life of the batteries. Most of my life I was always taught that a long slow trickle charge was best for batteries, but I’m finding out now that isn’t necessarily true even for flooded batteries.

What I am suggesting is if you don’t want Solar and will continue to charge with a generator, look into a Honda as they are relatively inexpensive to both purchase and operate, and when they finally wear out, there is no install to worry about either.

However it’s my opinion that for long term cruising where most of us cruise, Solar is hard to beat.

Of course LFP changes things, just in my opinion, I’m neither wealthy enough, smart enough, nor motivated enough to go down that road myself, I’ll wait

[Exile]

Your Lifeline's are rated at 220ah each @6v. So that's 660ah @12v. If you're recharging at 75% then you're only putting (roughly) 10% back in with a bulk charge, or ~6-7ah (theoretically). With a 100A charger . . . ok, I get it. Unless you're needing to run the diesel genset for other reasons, then the Honda is way more efficient -- for bulk and absorption charging (thanks Stu ).

I actually did have a Honda 2000 onboard for awhile, but mainly as a backup to the diesel genset for some longer trips to the Bahamas, etc. I used pigtails to plug the Honda into my 30A shore power outlets. My boat doesn't have cockpit lockers, and I wound up stowing it (w/o gas) in the only other place I could, namely a fwd lazarette. It wound up with a lot of surface corrosion along with plugged-up carbs from pump gas ethanol residue, but those issues would now be pretty easily preventable (didn't know any better back then). I ruled out stowing it on deck or in the cockpit because of salt splash, but maybe a sunbrella cover could help with that. Could be a good solution until I get some solar installed.

Btw, I got 8 years out of my last set of Lifelines, but that's not a great comparison since it's probably fair to say that most of that time I was plugged into shore power. With somewhat regular top-offs away from the dock, I would hope they could last 4-5 years, but maybe that's wishful thinking.

[a64pilot]

My background was I was VP of an aircraft manufacturer, Lifeline started from I believe the Concorde aircraft battery, I had for years tried to get them as OEM for our aircraft, but the owner shot me down repeatedly as Gill basically dumps batteries to manufacturers selling them very cheap, so that they can claim that they are OEM and many people not knowing any better when it comes to buying a new battery, want what came from from the factory, assuming its good quality, when in fact it’s not, it’s the cheapest the factory can buy. that usually goes for filters and other consumable items too, it’s called smart business.
Anyway the Concorde / Lifeline battery is family owned by the Godwin family, and as I had tried to get them as OEM for our aircraft I know them.

When I called them before retiring I assumed partial SOC cycling for most of the week, with twice a week getting to 100% SOC, I was told that as long as I equalized once a month to expect five years.
Now as I have a kilowatt of Solar and will run the Honda every day for half an hour or so, I get to fully charged, every single day. So I’m hoping to get more than five years, cause I’m at five years already and have noticed no drop in capacity, although I have done no real cap check. What I do is compare amps used with what my smart gauge says SOC is. Assuming the SG is accurate, that ought to give me a rough cap check.
It’s no replacement for a real cap check, but it ought I hope to give me warning of impending failure, before it occurs. It ought I hope to be good enough.

From what I can tell when you buy a Lifeline battery, your getting an aircraft battery, with a different label. I tired to do my homework as best as I could and from what I could tell, Lifeline when faced with different options, always picked the option that resulted in longest life, even if it was the most expensive option.

However there are “features” of any AGM that make it a questionable choice for a cruisers bank.

Now Gel from what I can find out in my research, will give me at least as long a life time with my kilowatt of Solar, without running the Honda.
I can’t determine why the Gel chemistry isn’t the choice for a cruisers bank, I must be missing something.

[waterman46]

Yes its adviseable to have a second battery charger if you have a 750AH total bank. Especially if you have 12V holding plate refrigeration, which needs a lot of DC current over a 2 hour period, you can provide while gen is running.
Don't often run generator to get full charge. When cruising you will have solar and/or several hours motoring to get to next destination around once a week to fully charge batteries. Or use FLA not AGM and full charge less often.

[Kenomac]

I’ve just been running the 10kw generator which has pumped in over 80ah into my house battery bank over the past hour while the 125amp chargers were running between 35ah and 80 going in during absorption. Whilst I also heated 14 gallons of hot water, made 20 gallons of fresh water and did a load of laundry in hot water.

Used about 1 liter (.25 gallon) of diesel costing 62 cents (duty free) which I thought was a good deal. Solar will now bring the bank up from 95% to 100% by late afternoon while I make an additional 20 gallons of water using our Spectra d/c watermaker.

Larger battery chargers work well, the Trojan 450ah house bank is 8 years old.

Ken

[ranger58sb]

Originally Posted by a64pilot

I do have a Diesel generator, but hate to use it when the Honda will do the job, to be clear it’s the hours I hate to put on the Diesel, plus it’s a bear to service, not really all that hard, just the Honda is so easy to service.

How many hours on it? Often it's a "use it or lose it" proposition.

Our circumstances are different -- electric galley, no solar -- so we have to run the thing about 2x/day at anchor for cooking and making hot water -- but that ends up being sufficient for battery charging (Lifeline and Odyssey AGMs) for a long-ish time between shorepowers.

FWIW, I'd much rather use a built-in diesel genset and then bite the bullet when it comes time for service... compared to fooling around with a portable. Happens I just did our annual "Spring" service yesterday (1300+ hours), took about an hour to do the Racor, change the zinc and impeller. Not an easy location, semi-uncomfortable... but then it should be good to go until the Fall oil change.

Different strokes, of course...

-Chris

[a64pilot]

It’s got about 800 hours on it, and like Ken I have no problems with running it to wash clothes, make water and maybe heat water, or rarely when it’s just too hot and we want AC. We heat water every day as she had rather have a hot shower than a cold one.

Just from a financial position, I believe it’s cheaper in the long run to run the Honda when you need power, just not a lot of power, and run the Diesel when you can use more power than the Honda is capable of.

If we were full time, and never in a Marina then our generator use would likely approach 1000 hours a year, which means of course a new one every five years or put back at least $1,000 a yr for the replacement.
A Honda is $1,000 total. So if you can put most of your hours on it, it’s less expensive.
So far we have cruised about 8 months a year, and four months in a Marina during the hot months that are Hurricane season, we also do all our DR appts, get our teeth cleaned, visit family etc then.
I think that may become our pattern, but we are new enough that we aren’t sure what will come next.