Lithium?

David Grimm

Squid!
Being lithium technology is so new I don't expect a lot of feedback on this question. I plan on putting (2) 12v 200ah prismatic lithium batteries in my boat in the next month. From what I understand my Xantrex Freedom Marine 20 inverter/charger will work with them on shore power but my 105 amp Fleece Neville alternator will most likely toast! So me question is should I get this fancy $2k Balmar 200 amp alternator, regulator and serp belt? I could probably just get the regulator but charging would take a long time. I have seen other high amp alternators but not many regulators. Or would getting a Victron DC to DC charger make more sense?

Dave. Screenshot_20200302-184613_Chrome.jpg
 

debonAir

Member III
Li batteries will accept a lot faster charge than lead. You will fry any normal alternator trying to charge them directly if they are depleted, especially a 200ah battery! Your question really all depends on how fast you *want* to charge them. The stock 50A alternator, if if could actually last through a charge cycle might take many hours to charge one of those, since it will regulate the voltage, not the current and the current will drop as charging gets longer. Your 100A alt is still a "truck" alternator and not really meant for continuous high-draw. The Balmar 200A alternator might charge you in less than two hours and won't fry up. A middle road alternative is to get a smaller Balmar and live with the longer charge cycle. If you stay under 90A you won't have to do a serpentine belt conversion (and you won't rob as many HP from your engine) and you can use the regulator's belt manager to control your charge vs. power-take-off to suit your needs. Another big advantage to the Balmar is that the regulator can monitor alternator and battery temps and modify the charge to account for that. Sounds like you have unlimited funds if you're getting 2 * 200AH Li batteries though :) So go for the big alternator and serpentine, which is the proper solution. One thing to also keep in mind is that it is really hard to tell the state of charge for Li batteries. Their voltage remains fairly even across discharge so, unlike lead batteries, you can't simply look at the voltage and get a rough idea. You'll definately want to use a battery monitor to visualize SOC.
 

David Grimm

Squid!
Ok. So that is the proper way to go. The below deck autopilot will soak up lots of power solo sailing. Even if I have to run the engine for an hour every 12 hrs I'm ok with that. Battery monitor just added to the list. Thanks for the reply. I appreciate it. That damn alternator is just so outrageously over priced for what it is. Ugh.
 

debonAir

Member III
Also, as Loren and other's will agree, a trip to Maine Sail's site is worth a visit for these kinds of questions. He's super knowledgable about Li batteries too. I just bought a Balmar 70A and regulator and that was expensive enough so I bought an "alternator protector" from Maine Sail's site. He answered my questions really fast, and his price was better than others. FYI - an alternator protector sits between the B+ output of the alt. and ground, and if B+ spikes, it shorts the spike to ground. This happens if the battery gets disconnected while the engine is turning, if someone switches the battery switch to off for example. All the magnetic energy in the coils in the alternator collapse and cause a spike. Cheap insurance given the Balmar's cost. The Balmars are super pricey but they have stayed in business for a long time at those prices so they must be doing something right. Im hoping mines lasts a long time!
 

nquigley

Member III
Just wondering - for an alternator that big, does one also need to increase the ventilation around it to keep it cool? (especially in tropical latitudes?) Are extra fans installed for that purpose?
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Just wondering - for an alternator that big, does one also need to increase the ventilation around it to keep it cool? (especially in tropical latitudes?) Are extra fans installed for that purpose?
FWIW, over two decades ago our mechanic advised me to : a) run the engine exhaust blower all the time the engine is operating, and 2) put the intake end of the 3" hose up near the alternator. He wanted the alternator to have good cooing air flow and to at least keep the ambient temp. from rising above the normal radiated heat from the block.
*Yes indeed, this scheme is for Diesel engines. And, unrelated to the safety issue for a gasoline aux. engine.

In his diesel classes, he pointed out that the designers of these engines planned for about 2 to 5% of the waste heat to be carried off by radiation, in addition to the main heat removal via the heat exchanger.

Also one more reason to keep your engine clean and not to let an "insulating" layer of dust and oil accumulate on it. Lots easier to trouble shoot problems on a clean engine, too. :rolleyes:
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
The question of battery capacity and alternator rating depends on how many amps the autopilot actually uses.

Does anyone have the amps burned in 24 hours in a heavy seaway based on experience?

Also, the singlehanded Hawaii racers, who feel wind vanes are not competitive, supplement their recharging with solar, and solar also changes the battery bank and alternator computation.

So--what's the max draw per day of an autopilot offshore? And how necessary is it for each of us to plan for that?

Another factor to weigh: on any family summer cruise, there's lots of motoring. We depart mornings with no wind, we cross calms to make schedules, we maneuver in harbors. Such motoring tops off the batteries "automatically," and pretty fast with a mere 100-amp smart alternator.
 
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toddster

Curator of Broken Parts
Blogs Author
I sent a couple of queries to BattleBorn about alternator issues. While they always responded, the responses were not very helpful. Or at least not very detailed. More along the line of "Yup, that should work!"
My (so far untested) hope is that the Atomic 4 will never, ever drive my 120-Amp alternator anywhere near its rated capacity, so it shouldn't get too hot. Wishful thinking? Since the switch, I don't think I've run the motor more than five minutes at a time. Maybe 30 minutes once or twice.
 

debonAir

Member III
"the Atomic 4 will never, ever drive my 120-Amp alternator anywhere near its rated capacity" I'd want to know what happens when it tries to though. 120A will be about 2HP draw on your 30HP engine, so it shouldn't really have any struggles driving the alternator unless it has a V belt drive. The alternator output will entirely depend on what kind / state of battery is on the other end. A fully discharged 100AH AGM will bulk charge at around 0.4C at 50% down so that'll be only 40A. On the other hand, with Li bateries which can take nearly 1.0C, if you had a depleted 200AH Li batteries like the OP is getting it could easily accept 120A. (0.6C) for over an hour. Hopefully the alternator's fans are sized for job but even better is to make sure you connect the regulator's temp probe to the alternator so it can lower the field and reduce the current. That's a must for large current alternators I'd think.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
My experience has been with 100 amp Balmar that with batteries (two 105 AGM Gp 31s) at 60 percent charge, the initial charge rate is 60-70 amps.

That quickly reduces as the batteries accept charge. In less than an hour the charge rate is down to 15 amps. I turn off the engine and the Victron monitor reads 85 percent charge in house bank.

I have heard "every 25 amps of output requires one horsepower." All I know is that I can hear the engine labor at first, when alternator outputting 70 amps. Presumably if the batteries were at zero charge, it would put out 100 amps--and perhaps the standard V-belt would be challenged. But the simple V-belt has always worked fine for me so far.

The Balmars can be set to restrict output, i.e. a 100 model can be detuned to 70 or 80 percent if belt slippage occurs. I haven;t found this necessary as full 100 amp output has never occurred. (the "sweet spot" for recharging is from 50 percent charge to 85 percent, more or less, in terms of running the engine as little as possible.)

I say this for what it's worth.
 
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gadangit

Member III
Does anyone have the amps burned in 24 hours in a heavy seaway based on experience?
We averaged 7.4kts for 3 days going to and coming home from Mexico a couple years ago. Beam and following seas in 17-25kts of wind. Not uncomfortable, but definitely slewing a bit with the odd wave. I stared at our analog ammeter for a while to get a sense and I figured it was averaging 8A on the peaks and generally 4-6A overall. Very non-scientific analysis, but enough to satisfy my curiosity and stop thinking about it. Raymarine with Octopus hydraulic drive.

We have a DC-DC converter floating our house battery at 13.6A, so never any amp draw change due to draining the battery.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Chris, let's call it 100 amps over 24 hours. My guess is it would take me 3 hours+ of alternator time to get that back. How'd you recharge and how big is your battery bank?

Oh, and David--is the point of Lithium batteries that they recharge much faster? I suppose I could look that up....
 
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gadangit

Member III
My setup won't be useful for the discussion, but at the time I had a 48V 270AH AGM plant and recharged that with onboard 5kW DC genset and solar panels. I don't recall exactly how often we ran the generator, but probably every day or so. No set schedule, just topping off as needed.
I'm now 48V 150AH LiFePo which my generator hammers with 93A for as long as it takes.
I think lithium is a wonderful technology, definitely made a difference for our setup. Yes, they charge faster (hence the discussion), maintain voltage under load and you can discharge very deeply. We swapped out 640lbs of lead for 114lbs of Lithium Ion. For no real loss in capacity.
 

Mblace

Junior Member
I have gone to a LiFEPo4 in my sailplane (did a lot of research) and intend to do the same on my E-25CB and for energy storage on my home solar. I agree that Li is a wonderful technology, but with limitations... There are several types of Li batteries (different chemistry) but all offer great advantages over lead batteries, not the least of which is weight. They cost more (about 3 - 5 times more) for the same AH capacity, but the advantages make it more than worth it - in most cases. Electronics in particular like Li batteries because they maintain constant voltage to about 95% discharged, where lead batteries slowly drop voltage as they discharge. They also have much higher charge-discharge cycle life (2000 cycles for Li vs. 6-800 for Pb). They charge quickly, but most have a rated max amperage for charge and discharge - so be careful. Li batteries designed to be "starter" batteries have a fast-discharge ability, but most LiFEPo's are rated for slower discharge rates and their onboard charge regulators may not be up to firehose amperage coming in. If you plan to use a Li battery to start your aux engine or charge off an alternator, be aware of this, because too high amps in or out cause heat buildup and may cause a fire. Matching the battery to the operating conditions is key.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
"Sailing Uma" went from four Group 27 lead acid batteries to 12 Lithium Ion batteries.

Uma has electric propulsion. Formerly they could motor for 15 minutes. Now they can motor for five hours at five knots.

His explanation is below. We have three Priuses, one a Prius Prime (best car I've ever owned), and electric is the future. But Uma's motor wouldn't even get Thelonious one way to Catalina. With my diesel and 60 gallons of fuel I can motor for 120 hours while heating water and keeping the beer cold too.

 
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gadangit

Member III
His explanation is below. We have three Priuses, one a Prius Prime (best car I've ever owned), and electric is the future. But their rig wouldn't even get Thelonious one way to Catalina. With my diesel and 60 gallons of fuel I can motor for 120 hours while heating water and keeping the beer cold too.
Yep, the problem with electric propulsion has never been the motor, always with the storage. The 3-phase squirrel cage motor has been virtually unchanged from Tesla's version circa 1890. And the lead acid battery has never really changed since the leyden jar. But the revolution is on the way,

Remember when everyone was poo pooing dacron sails and fiberglass hulls? I kid, I wasn't born yet. But change is constant and I believe we are truly living in the golden age of materials science and information.
 

Tin Kicker

Member III
I've investigated mishaps involving batteries for a long time and was the 787 Airworthiness investigator. Lithium batteries have now been in production for 30 years, so not quite a new technology anymore. While there are all sorts of lithium batteries on the market, the ONLY battery chemistry to install lithium based batteries in a boat is LiFePo4 with a BMS (battery management system). Stay away from any of the chemistries which have cobalt, as when it misbehaves, it is more energetic and capable of fire. Battleborn and the other name brands are all well tested and have great safety histories but they are expensive.

Great resource for anything lithium &/or solar: https://www.mobile-solarpower.com and his Youtube channel: https://www.youtube.com/channel/UCoj6RxIAQq8kmJme-5dnN0Q

Diversion for a related subject:
We all have carry-on lithium batteries such as power tools, cameras, laptops, jump packs, vapes, etc. Since we consumers have no idea what the chemistry is and consumer products don't have a great history (apparently includes Conception dive boat fire), treat all carry-on batteries as having the potential to overheat at any time. Random factoid of the day: Of the lithium battery related fires in airplanes (it's common), more than half are spare batteries!

Have a way to (1) control any flame or smoke until (2) you quickly pitch them overboard. These two steps are mandatory because the smoke can quickly overcome you in a cabin, you can not put out a lithium battery fire, and the flame or radiant heat has a history of igniting things nearby such as wood, fabric, and foam (which releases cyanide gas when burning). The answer to (1) and (2) are actually quite simple.

First is to simply have a couple of inexpensive fire blankets (fiberglass) to cover overheating batteries and control where the flames go. Example: https://www.amazon.com/Tonyko®-Fiberglass-Fire-Blanket-39-inch/dp/B07SKDDZVT/ref=sr_1_10?dchild=1&keywords=fire+blanket&qid=1583512698&sr=8-10&th=1

Second is when not in use and especially when charging, to keep batteries or devices in a steel case (loosely wrapped in a small fire blanket in the sink would work too) that does NOT have a tight fitting top. Use something to loosely separate individual ones to prevent physical damage. Ammo boxes are great for this. Do NOT latch the top tight to prevent pressure from building which can make the box burst.

I can be reached thru my website at: www.HowItBroke.com

Bob
 

Tin Kicker

Member III
Hmm, my AGM banks sound pretty good. I could not reach the batteries in a fire situation.
The LiFePo4 house and start batteries have not been the problem. If you really are worried, just have a way you can flood the battery box from the sink.

The problems are with the carry-ons catching other items on fire.
 
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