Remove the alternator - crazy idea?

[s/v Jedi]

Originally Posted by The Yacht Rigger

I tried one of these back in 2054, but then I got stuck in 2023. Can't seem to reprogram it correctly.

You must have bricked it. Maybe in 31 years you can send it back for replacement

[hjohnson]

Originally Posted by sinnerman

I use a flux capacitor on my boat.

It also allows me to "relocate" the boat when there is no wind.

I purchase the plutonium online from Amazon and Alibaba.

cheers.

Sadly, my boat can only get to 6kts under a good stiff breeze, nevermind 76.5kts. Guess I'm stuck in the present.

[Wolf Pack 2]

Originally Posted by s/v Jedi

I’m afraid you missed the need for electric power to the starter motor but when your house battery is big enough it can do this too.

My 4LH Yanmar had three alternators: the oem 80A one charging the start battery and two huge Lestec 225A alternators, 450A total, to charge the house bank. Imagine the size and weight of the brackets. It didn’t end there, there was also an engine driven crash pump connected to it, weighing even more than one of those alternators.

So I removed the pump, removed all three alternators and every bracket related to this, as well as the extra pulleys. Then I installed the Balmar conversion pulleys to a serpentine belt and their 170A alternator with tensioner etc.
This simply charges a 12V Odyssey TPPL AGM battery that is used for starting and other 12V loads like powered winches.

As we don’t use the engine often, I also have dc-dc converters to keep the 12V powered and the battery is just to assist with peak loads.

I too installed a Balmar on my port side with an internal and external regulator, my electrician told me you can’t mix batttery types so out from my lifepo4 comes 2 dc-dc chargers for the start batteries and I also have the ability to start my yanmar 3Jh5Es from the bank itself. If you’re worried about the alternator just disconnect the tickler wire that sends the signal to charge and she’ll just be a passenger as it’s pulley is needed for the water pump.

[Dave9111]

I would not remove the alternator. As has been said, its a source of power that is already one the boat. Why remove it. Adapt!

LiFePo batteries have some quirks just like Lead Acid. The alternator was designed to charge the start battery. Leave the start battery as lead acid. They are cheap and you likely already have one.

You can add LiFEPo batteries to your existing mix but you need to do a few things.

1. You need to limit the charge current into your LiFePO battery bank so you don't overheat your alternator. The key to fixing that issue is to make sure your alternator effectively limits the current it puts out without self destructing. Get a better alternator or an external regulator/diode set for your existing alternator. Balmar and others make all of that stuff.
This is really an alternator issue.

2. Get the juice to your LiFePO battery bank without draining your starting battery. That requires a battery isolator. They are cheap. Like less than $100 for a 200 amp isolator. Its not likely that your alternator can put out that much current anyway unless you have a dual v belt drive or serpentine drive. If your alternator can put out 14.3 to 14.4 volts you can nearly top off your LiFEPO batteries without any special ($$) DC-DC charger. You really don't need to fill your Lithium battery bank to 100% except every few months so the pack will equalize. To do that, keep a Lithium charger onboard and charge the pack to 100% while plugged into a dock. You were going to need a lithium charger anyway, now you are set.

That's it!

Fix your alternator and get a decent isolator between the lead acid battery and the Lifepo battery pack and life is good. The isolator just needs to prioritize the charging battery first and then connect the LiFePO battery pack when the charging battery is at voltage.

Dave

[CaptainRivet]

Originally Posted by Dave9111

I would not remove the alternator. As has been said, its a source of power that is already one the boat. Why remove it. Adapt!

LiFePo batteries have some quirks just like Lead Acid. The alternator was designed to charge the start battery. Leave the start battery as lead acid. They are cheap and you likely already have one.

You can add LiFEPo batteries to your existing mix but you need to do a few things.

1. You need to limit the charge current into your LiFePO battery bank so you don't overheat your alternator. The key to fixing that issue is to make sure your alternator effectively limits the current it puts out without self destructing. Get a better alternator or an external regulator/diode set for your existing alternator. Balmar and others make all of that stuff.
This is really an alternator issue.

2. Get the juice to your LiFePO battery bank without draining your starting battery. That requires a battery isolator. They are cheap. Like less than $100 for a 200 amp isolator. Its not likely that your alternator can put out that much current anyway unless you have a dual v belt drive or serpentine drive. If your alternator can put out 14.3 to 14.4 volts you can nearly top off your LiFEPO batteries without any special ($$) DC-DC charger. You really don't need to fill your Lithium battery bank to 100% except every few months so the pack will equalize. To do that, keep a Lithium charger onboard and charge the pack to 100% while plugged into a dock. You were going to need a lithium charger anyway, now you are set.

That's it!

Fix your alternator and get a decent isolator between the lead acid battery and the Lifepo battery pack and life is good. The isolator just needs to prioritize the charging battery first and then connect the LiFePO battery pack when the charging battery is at voltage.

Dave

Key to your number 1 is temp control, thats the real alternators issue. that then tells you how much you need to limit current and that depends on each individual install and specs of your alternator (current delivery and what stator temps it can withstand, normal one max 130 degrees celcius, then the isolation lacquer of the coil will be destroyed. 110 degrees if max output with reduced lifespan 95 degrees for optimum lifesapn and max output compromise.

You have 4 ways to do that.
1) modify your existing alternator and add an external regulator WITH temp control sensor as if you modify you loose the internal one. The sensor is placed on the case best somewhere in the pulley facing front but next step measure the temp difference between stator temp (the hottest part that needs limitation with an IR temp tool) and what your sensor measures, substract that delta from 100 degrees celcius and you have the temp parameter to put in your regulator, it delivers you the max current in your installation dynamically. In case of a sudden disconnect you have to make sure the BMS cuts the field wire first and add a surge protector.
The way to get around modifing your alternator is to use Nordkyn VSR200 regulator that works via the sense wire
without any modification to alt. VsR200 works with a lot alternators that have internal temp regulation like Mitsubishi 115A found on all newer Volvo D1/2/4 and partly 6+small Yanmar or the Valeo 125A found on various manufaturer. Be careful it must be originals the aftermarket ones mainly don't have this temp regulation!!! In a well ventilated engine room the 115A Mitzi delivers 85A continuously with the VSR200, in reality most heavy duty small case alternators in that spec range won't do more or maybe max 20A+ for 2000Euro invest...more you only really get with large case alt that most likely won't fit in the original location and be up for 3000Euro+ if you don't DIY everything.
2) if your alternator has internal temp regulation (like original!! 115A Mitsubishi or the 125A Valeo) then you can add a splitting diode like Victron argofet and connect to lithium house and to a lead starter battery. The lead present the dump load in case of a disconnect and also limits current output of alternator and the voltage drop on the diode makes sure that even at 14.7V alternator output only 13.8V or less gets to lithium. The internal temp protection protects your alternator and dials it back when needed. The Mitsubishi 115A internal one is set to very conservative 85 degrees. Like this you can charge a lithium to about 95%, the rest your solar can do from time to time.
3) connect your alt to your starter and use a DC2DC charger. If you have no glue about real temps at the max output capabilities of your alternator i advise max 40% of its rating and add 10A charge for the starter, that together shouldn't exceed 50% of the rating. This limits an 80A alt to 40A and most likely avoid burning it out. I say most likely because you have actually no glue at what temp your alt is really working and if you are in the limits or actually could go to 70% of rating because your installation is well ventilated and the alt has enough self couling capacity. If your alt has an internal proper working temp control you are save, if not like most older alternators that beings me to solution 4.
4) this is for all alternators without or insufficent internal temp regulation: install a temp probe at your alternator and log temps. Use a very hot day, all close up like its in normal operation. Now log in idle, your motorsailnig RPM and typical motor rpm at 33% or 1/3d current load of alternator capacity, so a 90A one on 30A and log temps at startup and all 10min till 2h of operations. Measure at 2h point with an infrared temp tool the stator temp so you get delta of your probe and stator. Add that delta to the temp results. Did your alternator get to 100 degress, if yes thats the current you need to derate it too. If not add gradually 10A load and do the same process then above. If you have derating you can do 2 ways. Way 1 buy a DC2DC charger that fits the derating, thats 100% safe compared to 3). Way 2 is the cheap but complex way: additionally measure field current/voltage at cold startup with motor rpm and at the 2h operation point. Thats the delta you have to derate the field current by a resistor. That has the disadvantage that during the cold startup phase of 15-30min depending of your installation less output of the alternator but its safe in permanent operation. Then use a splitting diode with lead starter like in 2) or connect it directly to LFP with a surge protector device and a diaconnect relay in the dield wire for the BMS. The resistor in the field wire limits the alternator also in max volt put out and limiting it to 30 till 50% should limits voltage to below 14.4V but you need to check that. This needs a BMS that controls the charges sources and just disengage the alternator at 95% SoC like eg a electrodacus, REC, Batrium, TAO BMS.

[Dave9111]

Forget about blocking diodes, they can work for adding lead acid batteries to lead acid batteries but not for adding lithium to lead acid.

You need all the Alternator voltage you can get from a stock alternator to get your lithium batteries charged to 95% +.

DC to DC chargers are expensive at high amperages and simply way more complicated than needed. For me, they are not viable. Too expensive.

I have this setup right now in a land vehicle and it works fine. This could easily be scaled up for a boat with a larger LeFEPO4 battery pack. That is my plan. I have this setup running a small refrigerator in a car right now 24x7, the same setup will be done in a food truck shortly and then my boat. Its effective and cheap. I travel a lot. I am not home most of the time. Gone 5 days a week. Having a refrigerator in a car makes sense when you are gone most of the time. I'm an engineer (ME/EE), who owns an electrical contracting business dealing with industrial controls for machines in manufacturing companies.

This is the isolator wiring diagram and text.

https://photos.app.goo.gl/LvRUQgakzcJ3ZC9B9

https://photos.app.goo.gl/L9SUTSg9bVXwRptZA

Keep in mind that right now, good 12 volt, 100 ah batteries can be had with a BMS attached for about $230 with a 5 year warranty. This makes lead acid much more expensive. These is in the form of a group 27 battery. It's all enclosed, stick it in a battery container and that's all you need to do to keep it safe. From what I can tell, LiFEPO4 batteries are dropping in price fast and I expect them to be in the $175 range next year. Dirt cheap. So I am not trying to optimize the life of the batteries to get 10 years out of them. If I get 4-5 years out of them, I will be still way ahead. I could create something super fancy device and program it to totally optimize the life of the batteries but it would be 1. Expensive in my time, 2. Complex and that is counter to "reliable". 3. Simply unnecessary.

This is the unit I am using right now. $52 for a 150 amp isolator.
https://www.amazon.com/AUTOHAUX-Univ.../dp/B0C2Z7T6ZL
This is not a "marine" unit so I might look harder for a tougher unit for use on the water, but the idea is the same. This is an intelligent device - microcontroller on board, etc. This is not a simple diode isolator. Its quite intelligent.

With a single Redodo 100AH, 12 volt nominal battery, the max charge current into the one battery is just over 20 amps. So that is about .2C with my Lincoln alternator running at normal speeds. The alternator is rated at 100+ amps, so I could probably charge at least two of these 100 ah batteries, maybe 3 off this alternator, no problem. The Alternator peak voltage is about 14.3 volts which is fine for Lifepo4. After driving this setup for 2 hours, my single battery is at 95% plus charge. Not 100%, but good enough for months of use before a full charge and equalization via the built in BMS. This same setup could be used in a boat or other vehicle if you have a healthy alternator with up to 3 - 100 ah batteries, with standard internal regulation and diodes or a lot more if you have an external diode/rectifier setup on your alternator with a programmable controller which includes temperature controls on the alternator.

This is an easy / dirt cheap way of adding lithium to your existing lead acid starting battery. You don't need to add a field disconnect to your alternator since the lead acid battery is never disconnected. The BMS's are built into the battery cases and covered by the 5 year warranty, which this manufacturer has been standing behind, so far.

I got lucky with this isolator on Amazon. There are at least two of these devices on Amazon that look very much alike. One is rated for 250 amps. I imagine that someone is making a very similar device for marine use. I haven't found that device yet. Let me know if you find one that works this way.

If you are messing around with batteries and alternators, you need some decent tools.
I highly recommend this multimeter/clamp on amp meter. I use it daily in an industrial environment and it out performs a similar Fluke Clamp on meter and is a fraction of the cost.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

PS: I am not making $$ off these Amazon links.

Dave

[kristjan]

Originally Posted by Rohan

If I understand correctly, seems like largest issue when switching to LiFeP0 from LA batteries is the alternator. You don't want it to burn out trying to charge lithium batteries, and you don't the BMS to kick in and cause a sudden overload.

So there are various solutions, like installing a temperature monitor, or a timer, or hook up to LA batteries and use a DC to DC charger.

Instead, has anyone considered a less complicated solution - getting rid of the alternator entirely? After all, your typical marine diesel engine doesn't use spark plugs, so you don't need a constant flow of electricity for that. You still need electricity for your gauges, lights, and things, but any halfway decent batteries can run those for weeks without a problem.

On top of that, people who made the switch to electric engines don't have alternators for obvious reasons. They rely on solar or a generator to charge the batteries if needed.

If I did this, I suppose I would still need a shell of an alternator to keep proper tension on the belts, but that wouldn't be a big deal.

Thoughts?

I ran my valve MD17C for years with no alternator. Batteries charged by solar, or a few hours of the Honda that made a cord to plug into my shore power inlet. Far more efficient than a diesel engine. And quieter.