Change to lithium

[sailorboy1]

when I changed over to LFP on my 2001 model boat the only thing I changed was the charging setpoints for the alternator regulator, the solar controller, and changer the battery charger to a AGM program that ok for the LFPs

The thing that turns off and scares a lot of boaters is reading the stories of people turning the whole thing into a science project

[Cpt Mark]

Interesting comments.
I changed over and to be safe and compliant with ABYC rules upgraded the cables to be proper sized for the new power requirements. New fuses on the batteries is a must as is a rotating on/off switch. If you don't upgrade your battery cables and fuses you are looking at a fire potential you probably don't want. IMHO, there is NO such thing as a drop in replacement. Yes, the battery will fit in your current box and has a pos/neg post but that's it. You now have much more power potential to go through your wiring.

[capn_billl]

Originally Posted by Hhew

I did something similar on my Bene 42, except I also changed the start battery to a Dakota LiFePo dual-purpose. This eliminates the problem of charging different chemistries and lets me use the start battery as the bow thruster and windlass battery as well. I upgraded the alternator to a Balmar with an external regulator. Have been cruising on this setup for a year and it works great.

It works great until both li batteries are fully charged and suddenly stop accepting current leaving your alternator feeding an open circuit. Which negates alternator voltage regulation causing huge voltage spikes.

My friend's boat just had that happen and now is replacing his alternator and entire DC system.

Either leave the starting battery lead which pulls down alternator voltage even if full, or buy voltage regulator and charge controller for alternator and a high voltage protection device.

My preference is to not re engineer the starting circuit. You are undoing 100 years of alternator experience with lead batteries.

Also where are you going to get a specialized Lithium alternator, regulate, and charge controller 3rd world?

I can walk into any shop in any town or village in any country of the world and walk out with a 12v lead battery, and heavy duty marine or tractor alternator that will fit on my engine and be good to go.

I'm putting 50 amp dc to dc lead to Lithium from lead starter to Lithium house bank through a fuse block, and cut off switch.

Anything goes wrong and my engine still works normally. Fuse blows before alternator fries.

[knutmi]

My best advice regarding a hot alternator: stop touching it.

Charging lithium or lead batteries, is there such a big difference? Yes, in many ways there is a big difference. The internal resistance in lithium batteries is very low. If you convert from lead-based batteries to lithium batteries, you can also halve the Ah. This means that many have converted from large AGM banks to smaller lithium banks. We have seen many boats with 600-800-1200 AH AGM banks being charged with for example Volvo's 60 A or Hiatchi 60 Ah or Hitachi 80 A alternators. Then there was never any talk of hot dynamos. Large AGM banks can receive a lot of current over a long period of time and should have caused many problems with hot and burnt dynamos. But this happens very rarely. A dynamo is designed to deliver a lot of power over time and it does that well. The paradox is that as soon as lithium batteries are mentioned, regardless of whether it is a single battery or a larger bank, the topic of hot dynamos and Victron's video often comes up. Many customers react to the video and become concerned about the alternator in the boat and wonder what to do to protect it from overheating. Some believe that a DC-DC charger is the solution. Others think that they have to get hold of "something" that reduces or limits the current in some way or that they have to change the alternator and install an external regulator with a temperature sensor. The theories are many. Maxpower (where I buy Lifpo4) experience, after supplying lithium batteries for nine years and to more than 1,500 boats, is that we do not.

I have a VP D1 with Mitsubishi 115 amp alternativ. One AGM start battery a Victron Argofet battery separator and 2 100Ah Lifepo4 with 150 amp BMS with new 35 mm cables. Yust replace 4 100Ah lead acid.
Have giving me power over 5 years and not a problem.

[Stu Jackson]

Originally Posted by knutmi

We have seen many boats with 600-800-1200 AH AGM banks being charged with for example Volvo's 60 A or Hiatchi 60 Ah or Hitachi 80 A alternators. Then there was never any talk of hot dynamos. Large AGM banks can receive a lot of current over a long period of time and should have caused many problems with hot and burnt dynamos. But this happens very rarely.

This is somewhat misleading. Why? Because Hitachi alternators have built-in temperature sensors, which reduces their output automatically, and this is a known feature or issue with them in the overall scheme of charging any kind of battery. That is also why they don't blow up or run hot, at the expense of reduced output in amps, even with internal regulators. Maine Sail has written about this and wrote this at least a decade ago:


Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorption voltage, then we also reduce the current the alternator is supplying.. Any battery at any state of charge simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

http://forums.sbo.sailboatowners.com...d.php?t=125392

and these, too:

http://www.cruisersforum.com/forums/...on-125843.html


http://www.cruisersforum.com/forums/...or-142083.html

[CarinaPDX]

Since you have a Volvo-Penta D series with Mitsubishi 115A alternator you can easily install an external regulator that will make it compatible with LiFePo batteries (or lead if you stay with them). The device connects to the external voltage sense line from the internal regulator so no hacking required, maintains the internal regulator's temperature regulation, and allows for regulating the output both above and below the internal regulator's setpoints (IIRC the Mitsubishi's regulator is set to 14.3V, which is too high for LiFePo batteries). It was specifically created for LiFePo batteries and supports communication with the BMS. It can also limit maximum charge current or maximum alternator output. It is the best solution I have seen for adapting the stock alternator for lithiums. It is also the best for lead batteries for the same reasons. https://nordkyndesign.com/product/no...ce-controller/ .

Converting to lithium batteries is definitely not plug-and-play. If you are lucky and have newer charging equipment (battery charger, solar and/or wind regulator, alternator regulator) then you might be able to just change the programming, but more likely you will need to replace one or more for a proper safe and reliable system. Often it will involve a change in topology, for instance from charging two battery banks from a single source through a splitter or charge relay to charging a single bank and using a DC-DC charger for the second. Even if no hardware changes are required it is important to carefully review the entire system with the needs of lithiums in mind. This may include larger wire sizes and certainly the use of Class T fuses very close to the lithium battery terminals. Merely dropping in the packaged cells and BMS systems into the battery box is a recipe for disaster without ensuring the system has been adapted.

While it is convenient to buy these packaged batteries there are advantages to buying 4 cells and separate BMS. I can put a 300Ah bank (4x Eve 300Ah cells) into the place of one of my existing 100Ah lead batteries (although the BMS would have to be mounted nearby). This allows for a higher quality BMS, that stays when the cells eventually need replacement.

Greg

[GILow]

Originally Posted by Sailorboyjo

Hi all! I have a bavaria sailboat from 2007 and the batteries have died on me. I am thinking of changing to lithium. I currently have 3 lead acid batteries x 140amps each and the plan is to get 2 x 200 amps. I am also installing 2 solar panels x 200 watts each. The generator on the Volvo d2 75 is the standard one from 2007 with 14v 115 amps. The battery charger is the standard Quick which was very common in all Bavarias.

The seller of the solar panels and batteries says that i can keep the same generator and charger, connected to the steering battery (lead acid) and simply add a dc to dc convertor between the lead acid starting battery and the new lithiums.

Has anyone done this? Will the old battery charger and generator work ok and safely with just the addition of the dc to dc convertor?

Thanks for any info!

This is a smart approach.

All the panic around getting more power from your alternator bothers me because who the heck runs their engine to charge their batteries these days? Solar is cheap, add more solar.

The proposed approach is exactly how I’ve wired the new boat, and that was starting from scratch, bare hull. Lead acid engine battery with a DC to Dc charger from the lead to the 24 volt LiFePO4 house bank. No alternator problems and cheap to implement with a couple of Victron Orions.

But add more solar if you can.

[Ballsnall]

Originally Posted by Sailorboyjo

Will the old battery charger and generator work ok and safely with just the addition of the dc to dc convertor?

It will work just fine, obviously a lot of good advice here on better ways to add a couple of lithium batteries.

Ultimately it just comes down to your main source of charging. If the bulk of your power comes from the alternator then spend another $3000.00 to achieve a 20% to 50% increase in charging, or $200 to keep approximately the same level of alternator charging.

External Voltage Regulator $400.00 + conversion cost $100.00
or
High output alternator $1200.00 with external regulation. (Plus engine upgrade)
Drive belt upgrade $600.00

+
Alternator Protection Module $70.00
New wiring and fusing $300.00
BMS with communication module $250.00

Or

30A DC-DC charger $200.00

[SOLAR SUPPORT]

It is possible to make a safe installation with batteries and chargers without Canbus communication. The most economical solution for a small boat is to use a high efficiency dcdc device that limits the alternator's label capacity by 50%. It is not possible to work 100% safely with a Li battery without Canbus communication and an external regulator connected to the alternator that charges it. Alternator without Canbus communication External regulator needs LA battery connection or APD addition and alternator temperature control also needed for 100% safety. The simple PreCutoff warning infrastructure required for safe operation of Drop-in Li batteries without Canbus communication with the alternator is not yet available for 12V Li batteries. An alternator that charges the Li battery and does not have Canbus communication must safely terminate the charge with the preCutoff signal coming from the Li battery. A simple and safe charging infrastructure for Li battery and alternator charging can be solved economically by adding the Li battery pre-breaker and alternator charging cut-off circuit to these devices.

[Statistical]

Originally Posted by SOLAR SUPPORT

It is possible to make a safe installation with batteries and chargers without Canbus communication.

That is an overlybroad and false statement.

[wholybee]

Originally Posted by Statistical

That is an overlybroad and false statement.

Are you saying that is is not possible to make a safe installation without CANBUS?

CANBUS is absolutely NOT necessary for a safe installation. It increases reliability when an alternator is connected to the Lithium bank without a DCDC or APD. And it provides convivence features. It does nothing to improve safety.

[sailorboy1]

I wonder how many of this topic threads there are here. I bet 100s. Yet people always pop in with what they must believe is new info.

[wholybee]

Originally Posted by sailorboy1

I wonder how many of this topic threads there are here. I bet 100s. Yet people always pop in with what they must believe is new info.

Not new information, but lots of misinformation, and lots of "new" "solutions" to problems that don't really exist. KISS.

[Statistical]

Originally Posted by wholybee

Are you saying that is is not possible to make a safe installation without CANBUS?

CANBUS is absolutely NOT necessary for a safe installation. It increases reliability when an alternator is connected to the Lithium bank without a DCDC or APD. And it provides convivence features. It does nothing to improve safety.

By bad. I agree. I read the prior post as saying the opposite.

[Ballsnall]

Originally Posted by wholybee

Not new information, but lots of misinformation, and lots of "new" "solutions" to problems that don't really exist. KISS.

Poor op just asked if a DC-DC charger would work.

So many helpful 'new' solutions provided he probably traded the Bavaria for a horse.

"But the benefit of LIFEP04 largely centers around the ability of that battery chemistry to take charge much more rapidly"

"Get something like a honda 2000 generator and charge the LiFeP04 from that"

"Put a lot of cooling directly on the alternator via 12v blower fan"

"Get a Balmar or competing high amperage alternator"

"*MAKE SURE* you have priced and sourced the pulleys and wider serpentine belt"

"you need to do an energy audit"

"The 400W you are planning might not be enough"

"expensive upgrades to the Alternator/Regulator might be in order."

"Li-Ion (lithium ion) or LiPo (lithium polymer), while cheaper and more space efficient, is NOT suitable for a marine environment"

"Always charge the LFP first"

"The result will be that the starter is always 100% charged and you will have a warm beer cause the fridge is not working"

"Charging the LFP first only works if you have built your system to include an expensive Alternator and External regulator"