What's the smartest "smart" battery charger for LGMs?

[gamayun]

Recently installed a bank of 4, 6-v Lifeline AGMs (GPL-4CT) and and 1, 12-V starter battery (GPL-2400T). Given what I've been reading about charging them correctly (whether at the dock or on alternator), I'm having concerns that the ProMariner (ProTech 1220i) that came with the boat, might not be up to snuff. It has been set for AGM1 type battery and 1 hour absorption. Now I am reading about smart battery combiners, and how some smart battery chargers are not really that smart, and temperature compensation during charging, and how much AGMs love fast C rates, and the Peurkert constant, and on and on till my head has started spinning. Also read Practical Sailors' article on the problems with sulfation when these batteries discharge. My plan is to upgrade the alternator (it's currently 50 amp), add solar panels by the end of this year, and do more off the grid sailing in another year or two. Right now, I keep the power cord mostly hooked up and the voltage seems to float around 13.3. This was a big cost investment and I'd like to get started on the right foot to get the most life out of them. If anyone has already gone through this thinking process and would care to share their thoughts on this, it would be greatly appreciated. If I'm overthinking it, I can take that criticism, too

[smac999]

20a is tiny for a ~400ah AGM bank. 80-100a would be better.


at 50% battery it'll take you 10 hours+ to charge. so your absorption is probably a little off. hard to pick a number with a wrong size charger. IE magnum recommends 1.5hours with a 100a charger for 400ah

[blackswan555]

Got a link to the battery manual ? what is the absorb voltage set to on charger ? 1 hr is too short for ab time, Do you have battery temperature sensors on all charge sources ?

Tim

[a64pilot]

We are in a similar situation, except I haven't gotten the batteries yet, I'm doing the charging first. I'm working under the assumption that ideally I'd like to get the batteries to 100% at least weekly, more often if possible.
My Solar MPPT is this one Outback Power Inc. - Charge Controllers FLEXmax 60/80
AC charger is this one Marine Battery Charger - Sterling Power ProCharge Ultra- Power Factor Corrected (PFC) PCU - 60amp
Note you can install more than one to increase power, but one draws almost a kilowatt, two would of course draw twice that, so even if the batteries could accept it, I'd have a hard time running 1.8 KW on a boat with a 30 amp AC current limit.
I have a Mark Grasser 160W alternator and his three stage regulator, Mark Grasser - DC Power Solutions Both Alt and batteries have temp compensation, as does the Sterling charger. I do not believe the Outback MPPT does however.
I also have a Nexgen 3.5 KW genset, plan is to run the gen a couple times a week to make water and get the batteries through the absorption phase early in the morning, then hope to Solar will get them to 100% during the rest of the day.
This is all theory so far, I'm not cruising yet so I cannot tell you for sure that it will work, but it should?

[Tibor]

I use a Seatec Smartcharger and have had no problems. I believe they were originally designed for marine use but handle all types of battery types. Never had any problem over the last 8 years using one.

[gamayun]

Originally Posted by blackswan555

Got a link to the battery manual ? what is the absorb voltage set to on charger ? 1 hr is too short for ab time, Do you have battery temperature sensors on all charge sources ?

Tim

I have the manual. It says absorption can be 1, 2, 3 or 4 hours (up to 14.7 v). What is the best absorption time? I think there is a temperature sensor on the Victron battery monitor that is hooked to the house banks, but I've only cycled through the settings to get to current and voltage. Why?

[gamayun]

Originally Posted by a64pilot

We are in a similar situation, except I haven't gotten the batteries yet, I'm doing the charging first.

Well, now. I never even considered this. That sounds like a smart move!!! I keep thinking that there might still be something (anything!) that had been on this boat when I first bought it that might still be useful to keep around. It's becoming less and less likely with each project

[GrahamHO]

Originally Posted by gamayun

Recently installed a bank of 4, 6-v Lifeline AGMs (GPL-4CT) and and 1, 12-V starter battery (GPL-2400T). Given what I've been reading about charging them correctly (whether at the dock or on alternator), I'm having concerns that the ProMariner (ProTech 1220i) that came with the boat, might not be up to snuff. It has been set for AGM1 type battery and 1 hour absorption. Now I am reading about smart battery combiners, and how some smart battery chargers are not really that smart, and temperature compensation during charging, and how much AGMs love fast C rates, and the Peurkert constant, and on and on till my head has started spinning. Also read Practical Sailors' article on the problems with sulfation when these batteries discharge. My plan is to upgrade the alternator (it's currently 50 amp), add solar panels by the end of this year, and do more off the grid sailing in another year or two. Right now, I keep the power cord mostly hooked up and the voltage seems to float around 13.3. This was a big cost investment and I'd like to get started on the right foot to get the most life out of them. If anyone has already gone through this thinking process and would care to share their thoughts on this, it would be greatly appreciated. If I'm overthinking it, I can take that criticism, too

I can only give you my experience. I'm sure there are a variety of smart (alternator) regulators. I have "Next Step" from "Ample Power" for over 12 years. I think they are still based in Seattle. It required a heavy cable from the alternator and as I was busy with work I got a sparky to install it. It's mounted on a board inside a quarter berth adjacent to the alternator side of the engine and above 2 of the batteries which being AGM can be installed under the berths on each side.


There are several connections including battery temperature and voltage sensing.
At the same time I replaced the stock 55 amp alternator with a secondhand 80 amp originally on a larger Yanmar. It required some simple internal work to operate with an external regulator.


Once it was all installed and operating correctly, the first thing I noticed was belt slip and a heavy load on the 20 hp Yanmar after the house batteries had been used at anchor overnight also running a small Engle electric fridge. Then there was belt wear and constant readjusting. The alternator got very hot. Too hot to leave my hand on it.


I fixed all that by having an engineer make a machined double pulley for the alternator for two belts. He also grafted a matching second pulley on the engine pulley which I easily removed to save his travel. I had the alternator pulleys made 10 mm larger diameter than original to increase the belt wrap and decrease the load on the motor and the revs of the alternator. That doesn't seem to have noticeably affected the charge rate. Part of the alternator overheating was from belt slip and part from working hard for the first hour. The oversize double pulley overcame both those problems. The original single alternator pulley was 2 bits of pressed steel which gave little contact area.


I understand that some competition motor vehicles use a larger pulley on the alternator to reduce the power absorbed by the alternator. From memory 746 watts = 1HP and 80 amps X 14 volts = 1120 watts. That's 1, 1/2 horsepower. The little Yanmar 20HP is really only 13HP or less at the prop. So with the alternator at full charge there is 10 / 15 % power loss. It's not a problem any more with the larger pulley and the charge is fine.


Then I installed a reasonably large plastic fan from an electronics supply shop. That blows onto the alternator from the front of the engine box and is wired to the back of the "ignition" switch accessories terminal with its own cable, and spade fuse near the switch. It operates all the time the motor is running and has given no problems.


I also have a hard wired Pro Tech mains charger for use at the dock but seldom use that now as solar is all I need. The Pro Tech is very good and you will be familiar with that.


After all that, the system works fine and my AGM house batteries must be 13 years old by now. With LED lights (now) and still with the electric fridge the batteries last fine overnight at anchor. My AGM start battery only lasted 11 years.
A weak start battery is risking over cranking and water in the exhaust.


I'm sure any good make of smart regulator would have required that extra work as the idea is to make the alternator work hard for an hour then step down the charge to avoid overcharging. It doesn't kick in until 10 or 20 seconds after starting, to avoid load and hard starting.


Oh, one other thing. My wind gauge not far from the regulator cable goes permanently 90* the wrong direction with the motor running and needs resetting for when I sail. I recently read a learned article written by a professor from the University of Oregon about marine electrical interference. One of the many things he explained was the effect of high current in smart regulator cables affecting instruments. One day I will wrap the cables from the alternator in wire braid and earth each end to see if that prevents the interference.


I hope I haven't put you off smart regulators because after all that, I think it was worthwhile. I have 2 Optima yellow top batteries for house, and one blue Optima for start. I also have a completely isolated smaller AGM with its own solar supplying the instruments. I cooked 3 chart plotters motoring long distance using the Autohelm both originally on the same house circuit. They were replaced free although out of warranty. An Autohelm will generate spikes both + and - which can't be filtered out. I eventually realised that. Hope it all helps you. G.O.

[gamayun]

Thanks, Graham! I just did a quick read, but it's going to take me a little time to digest this info. It's never simple, is it?

[GrahamHO]

Originally Posted by gamayun

Thanks, Graham! I just did a quick read, but it's going to take me a little time to digest this info. It's never simple, is it?

Sorry I did write a lot. The point I was trying to make is that with a smart regulator and an 80 amp alternator the alternator belt is trying to drive 1,1/2 horsepower. And the alternator is taking that much power from the engine at maximum charging rate.

I see from your photo, that you're near SF. It's a great city that I like. Ive cycled the bridge a couple of times in the last couple of years. I'll be there again for a couple of days passing through in Sept. SF is a little like but bigger than Auckland NZ where I live.

[ranger58sb]

Originally Posted by gamayun

Recently installed a bank of 4, 6-v Lifeline AGMs (GPL-4CT) and and 1, 12-V starter battery (GPL-2400T).

Given what I've been reading about charging them correctly (whether at the dock or on alternator), I'm having concerns that the ProMariner (ProTech 1220i) that came with the boat, might not be up to snuff. It has been set for AGM1 type battery and 1 hour absorption.

Originally Posted by gamayun

I have the manual. It says absorption can be 1, 2, 3 or 4 hours (up to 14.7 v). What is the best absorption time?

I've found the ProMariner manuals to be understandable only after about 5 years of re-reading...

There will be a place in there that suggests more absorption time for 8Ds than for Group 27s, or for multiple Group 31s, etc. A rudimentary table, IIRC.

You can probably substitute (in your mind) bank capacity as a guideline; more capacity should mean more absorption time. Your large-ish bank of 4 GCs is giving you about 440 Ah, significantly more than a single 8D.

I'd chose 4 hours. Especially since you're using a 20-amp charger.

We have two banks of 3x G31 AGMs so 300 Ah each (plus a smaller genset start battery), and I use 4 hours as the absorption time with a ProTech 1240. I'm a little underpowered in the charger department, and I have a plan to improve that, but it's been adequate so far.

-Chris

[a64pilot]

Read here about this serpentine belt kit
Marine Alternators, Advanced Alternator Regulators, Serpentine Pulley Kits, Battery Management System, Multi Battery Charging
Long story short, yes it's an old hot-rodder's trick to free up some horsepower by underdriving both the water pump as well as the alternator, but on our boats it may not be a good idea, for one thing by slowing the alternator down your increasing the heat, both by making it produce the same power but at a lower RPM, plus of course the cooling fan is turning slower. Both lead to heat in the alternator.
I went with a Balmar serpentine belt kit as I was unaware of Mark's. I would have liked to use his, largely as I believe an idler pulley is the best was to adjust belt tension and since I almost always run my Diesel at lower RPM's, I rather agree with his higher RPM set up for the alternator. Now if I cruised at 3,000 RPM or above, that might be different, but I never cruise more than 2300 RPM.
I think most sailboats don't run their Diesels at high RPM's

[a64pilot]

Originally Posted by gamayun

Well, now. I never even considered this. That sounds like a smart move!!! I keep thinking that there might still be something (anything!) that had been on this boat when I first bought it that might still be useful to keep around. It's becoming less and less likely with each project

I'm finding the same, my boat is an older one, and was adequately equipped for fine weather day sailing in the bay, not many of the systems are adequate for what I want to cruise with. So I'm slowly making my way through the boat changing and adding as I go along. Thankfully the original wiring is in excellent shape and I only want a few changes to the plumbing.

To some extent it's a delaying tactic, I have two years before I get the youngest in College and can Retire, so I'm using those two years to prepare the boat.
It would probably be smarter to wait until we are cruising and have a better idea of what we really need, but while I am working I can afford to buy boat toys, maybe not so much after we start cruising.

[gamayun]

Lots of great info to get me started. Thanks! I'm going to call Lifeline tomorrow because I'm just not seeing where this stuff is documented and I've scoured the internet. I've also had a note to call Balmar for a while to look into upgrading the alternator. To some extent, there's a part of me that thinks that the electrical components should just consist of a black box where one throws all the wires into and a magic switch just makes everything work. The functionality of all the parts and pieces is not so easy to comprehend, even though I thrive on research and information.

A64, I seem to be in a similar boat as you, metaphorically speaking I figure that by the time I leave the docklines behind, which is dependent upon the lifespan of my happy, healthy and awesome yet water-fearful, 12-y-o German Shepard mix, the boat will be completely upgraded and we'll be ready for a more simple life of constant maintenance. The projects have all been necessary with a 27-y-o, near-original boat. But it's kinda funny how there are some projects that I said I'd never do such as replacing the countertops and all new plumbing. It's been a bit maddening how one thing just leads to another....project.