I'm a highly accomplished electronic engineer in several things including power management systems and devices used in alternators and battery management systems. I passed by your video thinking "what is this non sense". I was quite surprised to find that you are quite technically correct in this video. Excellent job.

We’ve been binge watching your content lately. I love the idea of a Lead/Lithium hybrid bank and it looks like you did a great job on your BBMS product. I’m looking forward to this upgrade soon!

Your content and presentation is excellent. In the upper threshold of KZfaq influencers that I've watched over many years. I hope you keep up the good work and are taking care of financially for it

Thanks for the great breakdown, Clark! I'm a marine electrician and have hesitated to do lithium installs on my customers' boats because of the off chance that a BMS opens the circuit, frying the alternator and everything else. I REALLY like that the lead battery is there as a guardian.... and now with ways to thermally protect even internally regulated alternators I'm even more excited. I'm currently cruising, but will be back to work in a few months. I look forward to the next video and the possibility of installing a bank manager. Thanks again for the great video and sharing your knowledge!

Great information as usual. Your deep understanding of electrical engineering and excellent explanations are what make your technical videos so great. Often other channels, even when providing technical details, are just repeating what they were told by equipment manufacturers. Which is not all bad or wrong, just sometimes not quite all the details that we really need to understand all the issues and make the best decisions. I am looking forward to the alternator tear down. I have often seen people say that you should basically throw away an alternator if you blow the diodes and that has always seemed like it shouldn't be that hard to fix. Thanks for all the great videos. I don't even own a boat yet and may not for several more years, but I'm tempted to buy a BBMS just in case you quit making them. So please give advanced notice if you every decide to quit. But hopefully you will be hugely successful with it and keep making them.

Love this, thank you Clark! I've learned so much from you. Hope you and Emily are well and I'm so glad you're back on the boat.

The way the author of this channel explains and teaches reminds me of my enthusiasm for science as a youngster in class (late 70s-early 80s). I’ve had deafness since birth, and what little I could understand verbally was supplemented by visuals in the classroom. The author has many of the qualities of those teachers I admire and I appreciate that very much. Thank you so much. As an adult, with my deafness, KZfaq, with its closed captioning, has made the educational aspects much more accessible thank goodness. With the help of YT, I’m attempting to design & build a 100ah lipo battery system for my truck with limited space. I’ve purchased a Renogy 12V 30A DC to DC Charger with MPPT, On-Board Battery Charger. At the moment, after learning from this video, It’s clear that I need a system that is plug and play. I don’t have the capacity to understand all the science at play here. I use my truck daily as part of my job doing outreach and reliability and safety is my utmost concern. As well as affordability, which is why I’m trying to design and build it myself. I just wish there was a complete system I could install myself with more confidence in those goals. Any suggestions? Thanks for “hearing” me explain my situation in advance. Kind regards.

And people mistakenly think batteries and charging systems are simple and don't understand why I think they aren't. This post and the following comments/discussion support my contention. I rarely read comments, but I took probably an hour or more to go through these. Very informative and time well spent....👍👍

Great info as always Clark! Happy to see I am not the only one with vbelts that goes to dust! I will do the upgrade.😊

I love the content you guys are creating. Watched a ton and I feel I’ve learned so much. I currently liveaboard but I’m new to this life. Being a construction worker I’m financially challenged but very handy. With this information I’ve been able to enter a new way of life with confidence. Thank you so very much for all the knowledge I’ve gleaned from your content. So badly want a bank manager for my Pearson 40’s solar system and I’m starting from scratch. ❤

Excellent! I use a DC DC converter from 12v to 24v since my house battery is 24v, but I never thought of a thermal switch as a protection. Very simple and cheap :-)

Thanks Clark, now I have to figure out what kind of alternator I have. Keep the good stuff coming.

Clark, your tutorials are always full of great information. Emily help with mad scientist look. We all know he isn't mad.

I remember when alternators first come out I was working for the Ford company on the coast of Mississippi. They sent us to auto school in New Orleans and they explain the function of the alternator they were going to replace the generator on cars and they replace them were the last cars, we had that had generators 1960 alternators took their place the fields turned inside the armature right reversed to what a generator did and you had to have 1 1/2 volt to excite them to make them work. If you had a dead battery you could push that car all day long and it would never generate any power that was a long time ago we have come along way now with electronics . Grate job Clark as always

Great video, valuable info with minor amount of self-promotion. I see so many people switching to the external regulator alternators at great cost.

Great video, Clark! I was about ready to go out and buy a DC to DC Charger when you told us that I didn't need one because I bought your Bank Manager.❤

Thanks Clark. I'm finding you far more straightforward and informative than the battery manufacturers. Q: If I go either the dc-dc or Battery Bank route, d o I need to install a monitor or alarm/fuseto let me know if it fails? Or, is my first indication smoked alt diodes. I sent an inquiry to LiTime, asking if they are recommending any sort of dc regulator. So far, no response. And I'm finding lithium battery ads pushing their products as "drop in replacements" for lead acid batteries. The alternator is a convenient back-up for cloudy days, so I would really like to retain it as a charging source. However, I've just done an alternator replacement. It was not fun, easy, or cheap, and I'm not looking forward to doing it again soon. Thanks again for this video. It's a valuable service for any of us who go lithium! 4:56

I think it's wonderful that you're helping people. Thanks Clark. :-)

Glad to see you back on the boat.

More solid content, well organized. I'm definitely sold on the Bank Manager....but I don't have any lithium yet, so that order will be awhile coming. Cheers.

Great Lithium topic. If you have a Balmar with an expensive external voltage regulator, you can rig a switch that allows 50% output. You can run in 50% mode by default unless you want to "fast charge". Fast charging is used on exception and prolongs the wear on the water pump pully on my Yanmar 3GM30f motor.

Worked in power when many were new. This is also a great video for anyone thinking of building an off grid hybrid solar/mechanical system.

Good explanation on alternator diode while charging. That's important for people to know that it can ruin their batteries. Most people don't know.

Yes, I also forgot about this BMS protection in lithium batteries. One time it crossed my mind the possibility of replacing my lead acid battery in the car with lithium but I thought lithium is too expensive and also in an automotive environment where it becomes too hot, lead acid will be safer to use. Lead acid is already tested by time for decades in the automotive industry. This video is good 'cause a lot of people don't know this and even for people with technical background didn't realize this. It can easily be overlooked. The BMS indeed disconnects the battery from the load for protection. It has MOS-FETs, that works like a solid state circuit breaker. Thanks! 🙂

so glad I heard about you from another cruiser. this is HQ content! Thanks clarke!

From the title, I thought it's just another vid about bank manager, but its so much more. Looking forward to the tear down.

Excellent video Clark. Really informative. Thanks

Greetings from Portugal, Europe. Not sure why your video appeared in my YT feed but nevertheless, information greatly appreciated. Thank you.

Excellent words I now won't have to type either. Thanks. Some have played with varistors temperature compensated. A few sailors tired of the cost of the potted voodoo regulator went hardware simple despite being programers. I have a VSR daisy chain working well till more money. No heat at all. Your BMS in on my wishlist.

Great idea with the thermally operated switch to control the alternator. Will store that one away for future use. 🙂

Great video as always Clark, now that I know the bbms will protect my alternator from my lithium I can stop worrying about it.

For an extremely down and dirty (cheap) fix you could try putting a BZY91C18 (18V nominal) Stud Mount Zener Diode across the output (DC side) of the alternator. It's rated at 100W Steady State Power and 5000W Peak Pulse Power. They're about $20. Voltage will never go above 19V. Might want to include a current limiting resistor as well.

Great info, thank you. I have a Hi-bred Bp Chassis + LiFeP04 House. Morning is the high load 35A if the load goes over 35A the current to the LiFeP04 is chopped (not by the BMS). I don't know what is cutting the power. Any suggestion? 1993 Commons Diesel powered Motor-home. Have you looked into Starlink "Flat Mount"? I have, Looks Great. If you buy a Land Based, it can be Up and Down graded for Marine Service.

Good advice thank you.

THANKS for putting this video together.

That you Mr Data, very helpful.

Well done, thanks for sharing.

Fantastic. Thank you Clark. You explain things in a way for us that don't know much about this stuff so we can understand.

i love your videos as a new sailor the are so valuable thanks

My fix for this issue, tie in a supercapacitor in parallel to the battery. Iv'e actually blown out two solar charge controllers and nearly took out my inverter over a very similar issue. Smoke and flames, glorious flames! Many of the earlier LiFePO4 4 batteries had a lower cutoff voltage; right around 14.1 volts, the newer ones run around 14.6volts. Regardless, even if the BMS triggers, the cap provides enough cushion to allow the charging equipment to shut down safely. the supercapacitor did 2 things for me, it fixed this issue, it also allowed me to start fairly heavy motors rated at nearly the inverter capacity without issue.

Great video.... having the starter battery permanently connected to the alternator and hooking the lithium in parallel through a battery isolator solves the high volt issue, then with a long 10mm2 battery cable about 10 m long going to the lithium house battery gives enough resistance to limit charging current so the alternator does not run to long at full amps...which is what I did on my RV I love the vee belt comment as it was also known as a wedge belt, noisy friction stuff. I worry that the thermal switch solution may not be so good due to the inductive reactance of the field causing back emf high volts causing the thermal switch a problems..

Thank you Clark for this excellent episode. I have one question though. What if I have starting battery Lithium as well. Please let me know..

I'm usually not commenting on you tube clips, but i think i can add some useful info. For those who have newer boats with 2014+ Yanmar YM.. engines, they are all equipped with 125A 12V Valeo alternators, which have internal regulators - simple (dumb) voltage regulators. The video suggests to add thermal switch in the field current path to prevent overheating the alternator when LiFePO4 is used. Indeed, there is a Yanmar Tech bulletin out (YMTQTB17-007), which recommends to limit the charging current to 100A. This will limit the alt temp to 200 deg C, which seems high, but apparently is OK for Yanmar. Now, a thermal switch can accomplish this, but it does not address the voltage spike problem. Here is why. I'm assuming a typical scenario with lead acid starter and LiFePO4 house battery bank, both separated by a battery isolator. The LiFePO4 batteries typically use a battery monitoring circuit (BMC), which will shut off when a single cell (there are 4) reaches its max voltage. This shutoff happens instantly with severely unbalanced cells. The lead acid battery starter battery is normally fully recharged after a few minutes and therefore won't act much as a buffer raising the charge voltage above the 14.4V limit. The only way to remedy this is a controlled ramp down of the charging current so that the regulator can follow. So far i haven't found any specs for ramp down of BMCs, maybe someone can enlighten me.

I enjoyed this video. The idea I had when you were talking about using the lead battery to protect the alternator when the lithium battery opens it’s circuit and stops charging was, would one of those super sized capacitors used in audio amp installation work in place of the lead battery? The capacitors I’m talking about are over 1 farad and some even have digital voltage displays built in. Capacitors life generally lasts longer than lead batteries. Just a thought. Thanks for the interesting video. This is the first time I’ve seen your channel.

Sailing Yaba , needs to see this !

Wow - so interesting to see how much knowledge you have on this topic. Thanks for the vid. I read all the comments and have simple question: We have a wake boat with your typical 90A alternator and a single lead acid battery that runs everything. I just purchased a Blue Sea Systems 7650 Add-A-Battery Kit ($125 on AMZN), which seems to be very highly regarded. I had planned to buy a 100AH LIFEPO4 (probably CHINS - $300) to use as a house battery to power the upgraded speakers and amp we just added so as not to run starter battery down when anchored and cranking music. My rationale being that the LIFEPO4 would be ok with getting run down, would last longer, etc. Having come across your video, I now know that the very low internal resistance on the CHINS will crush my alternator when I start the engine and the Blue Sea switches to allow the alternator to charge the house battery. Adding $380 for a Bank Manager is not worth it for my needs. Should I just forget about LIFEPO4 and get a marine battery, or maybe just charge the CHINS with a typical battery charger (one with a Lithium setting) when back in the slip and plugged in to shore power? My Battery Tender brand charger is 4.5 A and has a LIFEPO4 setting. I know it would take forever, but don't care. Thanks for any advice

Really good video Clark!

Referring to diode failures, back years ago, I was having issues with cheap reman. alts. I found the issue was cheap diode bridges installed in the reman's. I found a source for plasma bonded diode bridges which fully eliminated the future failure issues. The cheap bridges were soldered diodes which we all know has a low melting point. The diodes were simply falling out of the alt on the road as I drove along. Now not all alts are constructed so the diodes can simply fall out of the cases, such as late model Fords or many others. Not that long ago, I was working on restoring a Ford 7.3L powered PU which I had installed a reman alt. One day I was working on something else and sparks just lit up the inside of that reman alt. It was on account of a diode bouncing around inside the case which in the end pretty much destroyed that unit. This is the second vid I've watched today from Clark and they were both educational. I've been working on engines in boats and autos most of my life and have learned something even today after over 40 years of mechanic work. Of course very little experience with LiFePo4 batteries in cars has been the case. I'm really liking the hybrid battery concept now.

I just found your channel. I assume your device will apply to an RV system? I have a dual alternator system as this vehicle was originally an ambulance. I have removed the rear batteries and now have the original dual battery system for the diesel under the hood. I have upgraded one of the alternators and plan on using the other alternator exclusively for my "House" batteries which are lithium. As I understand from your video, If I install a lead acid battery as an intermediate to the lithium batteries and install the Bank Manager to regulate the alternator it should help my second alternator live to charge the lithium battery bank along with 1200 watts of solar. Thank you for this video which has come up on my youTube home page!

Your flat (most times installed serpentine) belt also has substantially more surface area compared to a typical "V-Belt" so it wears out much more slowly. Also, a flat belt usually has a spring tensioned self-adjusting pulley that is easy to adjust tension for belt removal and replacement unlike a fixed position pulley on V-Belts which require more tools and frequent adjustment.

Good point about loss of battery load killing alternator, especially on diesel with no engine electical load. How about simply keeping the alternator / regulator always lightly loaded with a couple of engine comparment light bulbs?

For protection from sudden BMS shutdown, why not use a zener diode shunt? A zener diode is non-conductive until the threshold voltage is reached. Then it becomes a near open circuit. If you were to put a zener between the positive and negative charge wires, the voltage spike would be limited. Since the voltage spike would only last a few hundred milliseconds, the zener would be able to dissipate the excess energy with no problem. The alternator regulator will respond and bring the voltage back to normal and the zener shunt will turn off. I did a quick search and found 50W 50V and a 50W 35V zener diodes for around $10.

Hey there! Do you think that having a Smart BMS where you could control the current flowing out of the battery can save a lot of hustle ? Since i have limited my Smart BMS to only be able to charge with 35 Amps so there is no draw which exceeds these amperages. I am currently having a hybrid 2 x lead acid 100ah + lifepo4 100Ah and i am planning to change the cells to 280 Ah Eve which will consume a lot of current if i let it too. Great videos i am a big fan from many years :) Cheers from Bulgaria

Hi, great video and great explanations. But what about using a thermal switch that would activate an extra external fan when the alt. temperature gets to 100 or 110 degrees ? Nice work.

I have a few more ideas. You can have a voltage sensitive relay that connects your lithium to your lead starting battery only when your alternator is charging the disconnects when lead battery voltage drops to its resting state. It won't matter if your lithium battery disconnects because your lead battery is still connected. You can also upgrade the BMS in your lithium battery, my JK BMS turns off charging when battery is full but still allows discharge so there should be a voltage there for your alternator to see and not shoot up in voltage, that's what happens with my solar inverter. You can also maybe have a decent capacitor in parallel with your battery to hold a voltage in case the BMS shuts off while the alternator is charging, in theory the alternator will sense the voltage in the capacitor and think its a fully charged battery. You can also remove the regulator and diode assembly in the alternator and manually power the rotor field with your ignition or a switch and connect the 3 phase stator to a 3 phase bridge rectifier to get your high voltage dc and with a suitably rated capacitor to filter the DC then connect the high voltage dc to a solar regulators pv input to simulate solar panels. The charge controller will then handle all the charging to the lithium battery. I will be trying this to make use of a fried diesel inverter generator. Great info about the overheating and thermal switch mod too.

Awesome information thank you 🤠

Clark, loved the video. I have a very challenging problem though. My boat has 2 engines and 2 separate banks. Both banks can be charged by either alternator through a 2 alternator, 2 battery isolator. This is great when smaller similar batteries are used. My case involves a house battery bank (starboard) of lithium rated at 700 amp hours with 6 batteries in parallel. It is very unlikely that all 6 batteries would shut off, especially since the alternator really only wants to stop charging at about 14.2 volts. Since it goes through the isolator, a voltage sense wire is needed to the alternator due to about a 0.7 volt drop through the diodes in the isolator. This is one of my problems as the non house side with lead gets fully charged rather quickly essentially shutting down that alternator and now it contributes nothing through the isolator. This leaves the other house alternator doing the work to charge a 700 amp lithium battery. As you noted about alternator speed, I ussualy run 900-1100 rpm and air flow is probably not sufficient to cool this alternator resulting in a melted brush cage in my last alternator. My thought was to use a dc-dc charger from the Port Engine battery charging the Starboard engine that has the house batteries. The charger failed within about 10 hours running though. This also puts a constant 75 amp load on the port alternator at this low rpm. I am at a loss on how to get these 2 alternators to combine their strength to charge the lithium bank and have some sort of heat regulation without the 2 battery banks connected. This system was done for safety so if the house battery is depleted to a point that it cannot start the Starboard engine, then the port engine and generator battery are isolated and still full to get the generator with charger running as well as the port engine. This would charge the Starboard engine battery in short order to facilitate a start. There must be way to accomplish this without spending thousands of dollars on larger externally regulated alternators along with who knows how many other components. The temp switch may be a partial solution as I think if the voltage sense wire is disconnected, this would shut down the output and at least protect that one alternator from frying again. Getting the other alternator involved would be a bonus. Any thought by you or anyone else out there?

I use the Sterling Alternator Protection device $80 bucks specifically made for an alternator dump.

Does a Ballard external regulator protect the batter from BMS shutdown or you would still want a hybrid or secondary battery? Thanks great video

Always a great video

I have a Yanmar 56hp diesel which I think has an 80amp alternator. My starter battery is two 6V deep cycles in series for 12V. I have a victron 18amp DC/DC converter fed from alternator to two 12V 206ahr SOK LiFePO4 batteries. I like the idea of the thermal switch and having spare diodes on board. Any advice or critique here? BTW, really love the way you explain things. I am a retired chemist and typically chemists and engineers don't see eye to eye. My eyes , and ears, are wide open. Thanks Captain Qwiksword SV Gratitude Cocoa Fl.

Hi Clark I’m just watching one of your videos and you mentioned fitting a Lithium battery into a standard AGM battery Box , I have a Projecta power hub Battery box which has a 300 W inverter built in , and built in BMS , ot says a lithium battery can not be installed, is there a way round this as I like the Box , Thanks Clark Keep the great Videos coming 👍

I’ve always asked myself if a blackout was possible when BMS disconnects.. wasn’t sure if it only disconnected from incoming power or disconnected the whole thing.. now is clear.. doesn’t sound good to electronics and a little annoying..

very good insights for people, thank you Clark. 👍 Personally my next boatbis likely to need refurbishing and upgrades, along with replacements, Full wiring design check, Network Wiring, Lightning protection isolation and Bonding, New instruments (replacement originals that work, kept as spares for other boaters, and expensive but worth it Alternator, serpentine belts, external Regulator, standing rigging, running rigging, New Sails, and existing checked, valeted, and kept as a backup suit of Sails if good enough. That kind of thing. I'm still a bit wary of Lithium, after communicating with a Chinese Manufacturer. Like Lead, Lithium Hates being discharged below 50% Capacity, and you lose recharge cycles each time if you do it for longer life, they don't appear to like being charged over 85% apparently, so useful non damaging capacity appears to be between 85% and 50% , so a tual useable capacity would be 35% .? Now Lead Loves being charged to 100% right? So bon damaging capacity therefore looks to actually be 50% right, plus Lead batteries are easily and fully recyclable? Plus the extra weight, can help put displacement down low where it is useful. A badly treated AGM Battery can last as little as 18 months, but we'll looked after, 10 years. How long do badly treated Lifepo4 Batteries last ? What is their Maximum Life ? Information on those factors, are highly noticeable by their absence aren't they ? So I may go with deep Discharge Dual Purpose AGM, and Never Deep Discharge them (even with Lithium, deep Discharging Damages them. Any experience with Carbon Lead Clark ? They look interesting. As an aside, Offgrid on my Smallholding, I got 15 years outbof a bank of heavy Duty Cheap Agricultural Tractor Batteries, and only lost them thanks to Not forecasted extreme cold down to minus 45 degrees C cracking their cases. Never discharged below 50% and usually a couple of volts higher than that. I won't have "Normal" Lead acid Batteries on a boat though, must be sealed. Best Wishes. . Bob 👍

Very informative. I bought a NOCO lithium battery for my motorcycle. Is this scenario possible? What remedies can I use if that's the case? BZY91C18 diode?

I just picked up 2 100A Eco worthy lithium batts and likely won't be long before wanting a BM regulator from you Clark! In the meantime I might do a little DC to DC charging experimentation.

Great video! I am new to lithium batteries. I had an AGM battery in my cargo trailer hooked up to the alternator from my tow vehicle so it would charge along with the tow vehicle's battery while driving. I recently bought a LiFePO4 100 AH battery for the cargo trailer because I want to put a solar charger on it, and it has a 100 amp BMS rating. Basically I had the cargo trailer AGM battery in parallel with the tow vehicle's lead acid battery for charging off the tow vehicle's alternator when driving. I have a couple of questions. #1 - Can I even put a LiFePO4 battery in parallel with a lead acid battery and charge off an alternator? #2 - If I can put the two batteries in parallel will the tow vehicle battery act as a shunt to prevent the voltage spike when the LiFePo4 BMS shuts off?

Hi Clark, Rick Moore from Sophisticated Lady Explained the installation of a second 48V 5kW Balmar alternator, with individual Balmar regulators per alternator and a centre fielder to sync the alternators. The output of the alternators connect to a common buss with a feed to the 48V LiFePO4 battery system. So I don't know what happens to the alternators when the batteries get fully charged? His YT video SSL667

I know you are talking about a boat system what about 12v lithium car battery I've seen these as drop in replacement for car batteries and they come with built in car jumper feature in case the end user accidently drained the battery by leaving on some kind of accessory; headlights for an example, it could jump it's self. I know it's not a boat set up but how much different could a marketed car battery and alternator be from what's used in a boat other than voltage and amps ? I'm just asking because I thinking about getting one

Question: if you are running Lithium for the house and Lead for the engine that are connected to a magneto (modern outboard engine) do the overheating concerns still apply? Given the continuous running nature of a Magneto do we just let the BMS do it’s job to regulate amp charging of the Lithium batteries ? Or do we still need a bank manager or dc-to-dc charger?

Our RV (Pleasure-Way) uses the factory Mercedes Sprinter 200 amp alternator connected directly to 2 100AH Lithium batteries via a timed switched solenoid. The amps range between 90 and 130. It seems to function well.

Very interesting -- thanks! Btw, can't you have your lithiums and your lead acids connected in parallel? That way even if the lithium disconnects, you still have your lead acid connected?

If I have my lead acid starter battery connected to the alternator and completely separate from the lithium house bank and solar panels, is there any disadvantage to this other than being unable to charge the house bank with the alternator or use the starter battery as a backup house battery? If I go with this setup, what typebof syarter battery would you recommend? I understand that your videos and other resources should make this all clear on their own, but it's a lot to take in. Thanks!

Would this battery manager work for my Land Yatch RV as well? I'm rebuilding a 37' Fleetwood Limited Edition. SO far I've repowered it from gas to diesel. This gives me 600 HP and a 10 speed automatic transmission. My plan is to install between 800 to 1200 watts of solar on it and replace the house batteries with- 2 200 amp litium batteries. I will keep the lead acid cranking battery for starting. I replaced the 60 amp alternator with a 240 amp alternator so it can run both AC's while driving on the road. Thinking of converting to mini split air conditioner with dual cassette roof cooling units on the one base outside unit. Since my RV will be operated much like you folks in the boating world, I'm thinking I might need a way to manage my litihium batteries charging with my dc alternator. Most of this coach is being severly upgraded with lots of electronics that I would really hate to burn up. As my Daddy iuse to say, " It's only money, I'll make more". ps: I'm upgrading and remodeling my old coach because (1) it's been paid for for decades, and (2) because it has better aero dynamics than any new Class A Coach out there. And lastly, I'm a Tim Taylor kind of guy. It's one of my hobbies...

Clark, do you consider the argofet as a reliable protection for lithium when coupled to FLA?

very informative thanks

any plans to do 48V. i have a NiFe battery comprised of 36 600ah cells i had to put this in a shed do to hydrogen off gassing. i interested in expanding with Lithium LiFePo4 but have been looking for a way to get them to play nice. this looks promising but i could only find 36V version

Some BMW alternators are water-cooled with the cooling system coolant. You would have to make a pot to fit the alternator in with an 0-ring seal.

thinking of parallel connection (pbo2 & lifepo4), alternator connected only to pbo2, hopefully balance-charging changes the lifepo4 battery too :). thanks for bringing this to our attention :).

So I want to deck out my electric system in my Catalina 22. The goal is to do the Texas 200 comfortably. But is ac, inverter and lithium to much for such a small boat such as mine?

I just ordered 2x 280Ah LiFePo4 from eco worthy with 250A bms and your YT video caught my attention !!. 😮 Ohh ? However they will be charged by a Victron multiplus 12/3000 and a dcdc charger from the Engine battery which is in parallel with more 2 lead acid on the bow thruster / windlass with long HD cables. Do I still need to be worried ? Any thoughts greatly appreciated

Well, I picked up some thermal switches. Looking forward to the next video so I can learn what to do with it.

Another great video

Can you clarify for me. Can I use my lead start battery with my lithium house bank to create the hybrid, or do I need to add lead to my house bank?

Great video.

How about Lithium replacement in lights duty diesel truck? Replace the main battery with Lithium and keep the second as Lead to keep the alternator happy? Still need the Bank Manager?

My toyota hybrid does not have an alternator, Will a lithium battery instead of the 12V lead acid battery hirt the 12V charging system in the phase converter?

I was unaware about blowing my alt when the lithium is disconnected. Luckily, my truck AGM battery was there. Our Renogy DC-To-Dc converter failed out of warranty, but only a few hours use and I didn't know until the house battery was at 10.2 V. (We have a pull-behind trailer I've converted to lithium so it has a private hi-current plug for charging). Once at the campground, I ordered a 100W/ 0.1 Ohm resistor and wired it in series with the charging ckt from the alt. Renogy won't repair and I won't re-buy so I made up 3 switches and 3 heavy relays; one for direct, one for 0.1 ohm, and one for 0.2 ohm series resistance. So far at max draw we drop about 3 volts across the 0.1 ohm resistor, but as the battery charges, the current goes down, and the drop is less. I already have a 50 mv shunt current meter on the dash so I can monitor charging current. I don't care if the battery doesn't fully charge while on the road. We seldom dry-camp more than one night between campgrounds. But by switching resistors, I can fully charge my lithium, protect my alt, and not have to hassle with Renogy. All for less than $50. and I can fix it if it breaks.

This is how RVs are setup.. lithium batteries are connected to the started battery through a DC-DC charger. BMS are pretty stable nowadays, even the old crappy Chinese ones have become better and beefier than ever. The price of lithium batteries have dropped dramatically if you are running Lithium you should have an alternator that has a higher output. Best days of a boart owners life, the day you bought it and the day you sell it. I loved my boat but man was I glad I got rid of it. lolol Nice video..

4:29 would the voltage spike happen in an automobile with a lead acid battery if you disconnect the battery while the car is running? I’ve seen people do this to check to see if the alternator and after learning about lithium I’m wondering if that has been a problem over all these years?

If you confirm the voltage is close when you link them, could you just have a lead bat in parallel with the lifep04 when the engine is running and then disconnect the lead after while sitting, With like a bank selector switch?

Is it safe to have alternator connected to lead starting battery through stock wiring, then wired through a simple isolator and ignition-operated relay to the lithium house battery?

Thanks

One other thing that could really help with thermal regulation would be to opt for a compatible liquid cooled alternator. This should remove some of the RPM dependence to your charging system as there will always be a good constant flow of coolant through the alternator.

I like the concept of the BankManager. Could it be used in conjunction with something like a SBMS0 plus a DSSR20 that could switch the load from LiFePO4 to something like a hot water heater or electrical in-floor heating? It seems like a smarter BMS that switches _where_ the current goes might also save the alternator, no?

I run a dual alternator set up and have my battery bank on a 375 amp alternator with a external adjustable voltage regulator. Works great.

Electrician here: The voltage spike from open circuiting a large 12 volt alternator under max load can exceed 1k volts. This is why a TVSP device will help protect the alternator and all of the electronics in such events if you have a battery disconnect switch of any sort, including the BMS. If not using a lead acid battery in parallel, I would go with an adjustable external regulator that will connect to the BMS of the battery to regulate both current and voltage to provide optimal charging within the required range of the lithium battery. One can even set the output voltage of the alternator regulator slightly below that of the PV array charge controller settings so that the array will be prioritized over the alternator, plus the output of the alternator can be controlled to allow for de-rating if overheating is occurring. I believe that there are now can-bus controlled alternator regulators that will integrate with the entire system. Those lithium iron batteries are a big investment, and one will want to get the longest life out of them. The heat created by the alternator is a function of the winding resistance, the power output/field strength, the alternators cooling fan, and the temperature and volume of airflow in the engine compartment. The reason we use alternators over generators is that they have the ability to provide a fairly large output even at low RPMs by increasing the strength of the field windings, creating more current flow in the windings, thus more heat while the alternator fan and the engine fan are operating at low levels, thus causing more heat buildup under slow RPMs. Normally this is not an issue in running basic electronics and keeping the starter battery topped off, as the alternator will just be idling well under its rated maximum output. But add a load like a lithium battery capable of keeping the alternator at max output continuously, and that can really stress the alternator. One can help overcome this by using the above mentioned regulator, and by also using electrically operated and thermostatically controlled fans to cool the engine compartment, along with de-rating a larger alternator. A 100Amp alternator will have 1/2 the winding resistance of a 50Amp alternator, and will run much cooler when outputting 50Amps than the 50Amp alternator running at its maximum output.

Such an excellent video. I'm convinced you can confirm if my expensive way of keeping my alternator in check will work for my upcoming project. Mind you I'm installing these on a yamaha jetboat (because I have a very demanding audio system) So I bought an Epoch lithium battery 12v460Ah claims the following statement on the website: " CANBUS Communication allows BMS to communicate directly with Victron OS" I also bought a Balmar XT 250 alternator. I will be buying the all new Arco Zeus external regulator (it is a canbus enabled regulator similar to the wakespeed WS500) I will also buy a victron cerbo GX. I'm hoping the Epoch batteries internal BMS will connect to the Cerbo GX to be able to enable DVCC and then from the Cerbo GX to the Zeus regulator which then will control the Balmar alternator to shut off when my lithium gets full and stops accepting charge or out of balance etc any time it shuts downs. All concept and I already bought most of the expensive parts but really would appreciate if you would look into these specific products. I have a good feeling you will be familiar with the individual items I have listed and will have a stronger opinion on if they will be able to communicate in the way I'm hoping. Looking forward to your reply and thanks for the videos, cheers!

I have motorhome with lead starting batteries and lithium house batteries. When the engine is running, the Alternator charges both systems. This means the lead batteries are there when the lithiums turn off at full charge, and the Alternator is protected from damage. When the ignition is turned off, the lead batteries are completely isolated, they will not charge with shore power or solar panels. But there is also no power draw, so they can sit idle for weeks at a time. When the ignition is turned off, the 2 battery banks are cemetery isolated.

That's why the POS cable going to the DC to DC charger is coming off my lead acid starting battery so when the BMS disconnects the lead acid battery is the buffer for the alternator