Lithium Charging w/alternator

[Argosy]

Have 24V alternator. Just bought a Balmar Mc-624 voltage regulator.
Looking to install 24v lithium house bank using these: https://bigbattery.com/product/24v-100ah-li-ion-battery-box/
Have 24V 8D starting batteries

Should I just put a ACR between them? Then alternator to lead acid, or alternator to lithium (house) first?
Id like to charge house as much/quickly as possible.

 

[nosys70]

charging a 24v battery requires to get up to 29V.
a 100Ah battery can be fast charged up to 1C, so you need to make sure all the chain
can support that current (ideally you would not go over 0.5C, 50A)
your Balmar Mc-624 support max 10A, so you will be charging at 0.1C and it will take 10 hours.

 

[Argosy]

Mc-624 is an alternator regulator, and I think 15A field current... Alternator is 170A.

 

[Dauntless]

Check out this hybrid system.

Lithium-Hybrid

What is it and why do you want it?

www.zwerfcat.nl

This is the second of such articles on this forum and I found them both very useful.
I now have a hybrid system and it works exactly as advertised, in that my alternator is protected from the BMS disconnecting the battery and the LI gets charged quickly.

 

[Argosy]

Wow, I was pretty close to that solution, but am glad to see this as the only reason I was going to put a lead acid in line was to absorb any voltage spike.

Im thinking this combiner as it goes both ways

Cyrix Battery Combiners - Victron Energy

Automatically connect batteries in parallel when one of them has reached a pre-set voltage using the Cyrix Battery Combiners. Find a dealer near you.

www.victronenergy.com

 

[Dauntless]

I like keeping it simple.

 

[Pierre]

Check out this hybrid system.

Lithium-Hybrid

What is it and why do you want it?

www.zwerfcat.nl

This is the second of such articles on this forum and I found them both very useful.
I now have a hybrid system and it works exactly as advertised, in that my alternator is protected from the BMS disconnecting the battery and the LI gets charged quickly.

Thank you for posting this - most interesting and helpful. Not having read all is this BMS available to buy or is it a DIY project ?

 

[Sabre36]

Mc-624 is an alternator regulator, and I think 15A field current... Alternator is 170A.

#1 The specifications on that battery are completely lacking in information.

#2 What chemistry are the cells? Most 21700 cells are not LiFePO4. If they are NMC or LiCoO2 please be very careful..

#3 Please pay attention to the BMS specifications. From the scant data they give it would appear that battery has a max continuous rating of just 100A. With most of these FET based BMS's This typically means a "recommended" charge current of just 50A. Either way a 170A alternator is a poor fit for a battery with a 100A max continuous rating.

#4 A Blue Sea Systems ACR is designed for lead acid voltages, not Li-Ion...

 

[Popuptoaster]

I have been looking for a 24v voltage regulator that can lower the alternator output when it gets to hot, has anyone found a good one or am i going to have to buy an alternator specifically designed to charge Lifepo4 batteries?

 

[Sabre36]

I have been looking for a 24v voltage regulator that can lower the alternator output when it gets to hot, has anyone found a good one or am i going to have to buy an alternator specifically designed to charge Lifepo4 batteries?

The Wakespeed WS500 Advanced Alternator Regulator can do what you want and more..

 

[John Simmons]

I have a balmar mc612 alternator connected to a 12V 1000Ah LiFePho4 bank. I contacted Balmar about what settings should be programmed in, and they were super helpful.

One of the items that they were insistent about installing was a alternator protection device.

Affordable Electric Vehicle Batteries & Components from Electric Car Parts Company

Electric Car Parts Company is your one-stop-shop for affordable electric vehicle parts and components including batteries. Shop our selection and order now!

www.electriccarpartscompany.com

According to Balmar it will save your alternator and any electronics connected to the alternator in case the battery becomes disconnected either through some idiot switching the battery switch to OFF or the BMS taking the main battery offline. When the load is suddenly disconnected from an alternator, the output voltage spikes dramatically and at a minimum the diodes in the alternator are destroyed. The open circuit protection device that Balmar told me to buy keeps a load on the alternator at all times and supposedly keeps this from happening. I have never gone wrong listening to the Balmar tech support. I don’t have the courage to actually test the thing to see if it works though.

I presently have a similar hybrid system. Batt 1 is the house LiFePho4 1000 Ah. Batt 2 is a Lead Acid Starting Battery.

All of my charging sources (Balmar Alternator with MC612, Samlex inverter Charger, and Morning Star MPPT controller are programmed for Lithium charge profile). The BMS I use is the Electrodaucus SBMS0.

The sole exception is ONE 20 Amp Lead Acid Battery 120V charger that is connected to the starting battery for when I am on shore power or when the generator is on.

My usage profile is switch the 1/2/Both/Off battery switch to 2 (Start battery) start the engine or generator and let the alternator charge the starting battery for a few minutes as I pick up the anchor etc. Then I switch over to Battery 1 which is the House LiFePho4 and I just leave it like that.

My use model for the boat while at anchor or while sailing is one to two hours per day of generator run time to make water, cool down,the holding plate, and fast charge the Lithium Bank. At that time the small battery charger is also topping up the start battery. During the day the solar panels are charging the lithium bank.

Note that both banks are separated by the battery switch, but I can combine them if I want as was mentioned in the previous article. I have done that as the voltages are similar enough as to not cause any major problems, but in general the charge voltages of lithium batteries are higher than Lead Acid. If you permanently parallel connect your lead acid with the Lithium, you will overcharge the lead batteries and shorten their life.

My eventual goal is to move to all Lithium and get rid of the lead acid side completely. Unfortunately for me, the starting battery is only 6 months old, so I will continue using this hybrid system.

One of the other boats on the dock has a similar setup and he uses a battery to battery charger to top up his lead acid cells. I am only using the 120V AC charger I have because I already own it, and my stated goal is to move totally to Lithium when the last lead acid dies.

If I was going to keep a lead acid battery permanently, I would go with the Battery to Battery charger.

John.

 

[Danny]

It may make sense to keep your lead acid charging systems and add a DC DC charge. Then you can slowly migrate to LFP after you know how/if everything works. Here is my current system that is migrated.

 

[Argosy]

Awesome thread, thanks guys. Let me respond:
@Saber36 #1 - are you talking about the Model3 cell battery I linked? Specs are there, and answer #2 is it uses Model 3 cells. #3 is true, but when I have 4 or 8 of these in parallel, no longer an issue. Will not be starting battery. #4 ACR is a term not a specific product. Im looking at Victron.

@Popuptoaster - I have Balmar MC-624 for 24V (MC-612 is 12V) which has temp probe. You just put the lead on it on one of the alternator casing bolts.

@John Simmons - thank you for you detailed replay - this is great information. I did not get the "alternator protection device" from the sales rep I spoke to...but they were also dealing with a web hack so probably wasnt priority. with a lead acid in parallel per the hybrid system, this device is not necessary as well.

Your usage profile is very intersting. You must have a switch that allows for switching while running - blue sea makes these. you could probbly put an ACR style device between the batteries and eliminate the need to do this switch.

I was looking at the Balmar Battery to battery charger, but it is 30A only and much more expensive than other ACR style devices. Also would necessitate the alternator protection device, which I might grab just because anyways at $80.

@Danny I need the alternator to lithium battery then can do a b2b charge to starting battery. With 24V im limited in what I can find at higher amperage b2b charger if i wanted lead acid to lithium (other direction)...since I want to charge lithium as fast as possible

 

[Danny]

I have a Balmar 100A alternator and my MC614 only lets the alternator run about 40-50 amps of long periods of time because of alternator overheating. Yes. I can run 70A for a short period of time. I also have issues with a narrow alternator belt and strain on my water pump so running high output causes wear. I try and run my charging in Small Engine Mode explained in my video. I find that the 60A sterling gives me a bit more control over slow friendly, alternator charging and BMS integration. BMS integration is often the last thing people think about but perhaps should be the first thing? When your BMS shuts down your alternator you may be in a world of hurt and a good plan needs to be in place to recover. Lead acid charging voltage is higher than LiFePO4 voltage this compensates a bit for the power loss using the DC DC charger. Good luck on your project. I realize my scope is may smaller than yours so my application is far different.

 

[John Simmons]

Hi Argosy,

The switch I am using is a regular 1 Both 2 Off switch. It is a Make before Break so that theoretically the alternator never sees an open when you switch from 1 to 2. All of the battery switches are designed that way.

My Balmar is on a serpentine belt add on kit, which was stupidly expensive yet incredibly useful. No more belt dust, no more sideways torque on the water pump, no squeaking belts etc etc etc. Here is the link. I used to have to tighten the belt and clean up the black dust on a regular basis. Now, no work, it stays clean, and it is quiet.

AltMount® Serpentine Pulley Kits - Balmar

AltMount®Serpentine Pulley Conversion KitsBalmar’s Patented AltMount® Serpentine Pulley Kits Facilitate the use of Balmar High Power Alternators Better Power Transfer Reduced Vibration and Belt Dust Quieter Motoring Single Vee pulleys can only support alternator power loads (PTO) of up to 100A...

balmar.net

It wasn’t quite perfect and needed a bit of shimming, some machine shop work, but truly worth the peace of mind. I would highly recommend it. As Danny mentioned the temp sensor does kick in and back off the charging current to protect the alternator. You HAVE to use the sensor or you will be buying a new alternator.

I would buy the alternator protection device, it is cheap insurance just in case. Like I said, I have not tested it just in case it doesn’t work, but Balmar was real adamant about it even when you have only lead acid batteries.

I also agree with what Danny said about integrating the BMS with the system is key. Ideally if all of your charging sources are set up for lithium ion, then the BMS should never have to disconnect the battery to protect from overcharging. The converse of if the voltage drops too low because you have been remiss about charging and the BMS disconnects to protect the batteries can be avoided if you are aware of what your state of charge is.

One of the simplest and most useful battery monitoring tools is something like the Xantrex Link Lite.

LinkLite Battery Monitor

www.xantrex.com

Many vendors sell a similar product, but the Xantrex has been flawless for me. Some BMS‘s have this feature built in. I am not sure about your exact system, but this thing is an easy to install, easy to read, no calibration needed tool that always shows what your battery is doing. It is a good second opinion on what the BMS says is happening.

John.

 

[Popuptoaster]

I also have issues with a narrow alternator belt and strain on my water pump so running high output causes wear.

This is something I had not thought of so very good information to have, I don't think it will be an issue for me in particular though as I have a Gardner 6LW, it has it's own generator which is defunct but there is a large crank pulley designed to run alternators, it has to be large to get the alternmator spinning qquickly enough on a low revving engine which I thought might be information that may also be useful to someone else.

 

[John Simmons]

I would highly recommend the serpentine belt add on. I needed to shim the water pump pulley with some very small washers taped to get it perfectly alighted the crankshaft pulley. For the alternator to sit correctly, I had to have a special shim made by a machinist and some work on the alternator mounting bracket itself. It took 3 trips to the machinist to keep shaving the shim down by a few thousands of an inch at a time.

It is all straight now according to the metal flat ruler, and I am very happy with it. I would never go back to V belts. If I ever buy another engine that had V belts, this serpentine belt would be my first upgrade.

Balmar makes and sells great equipment, and their technical advice is outstanding. I have a 20 year old Balmar alternator that has been flawless. I wish everything on the boat worked as well and lasted as long as the Balmar stuff.

John.

 

[Dauntless]

We are up and running with a Balmar ARS-5 regulator that I had to rest to the user program.
I also added a temp sensor for the alternator.
Everyone is very happy. I used:
Bulk 14.2 v @ 120 minutes, max 70 amps
Abs 14.1 6 min
Float 13.3 v

My battery bank is only 200 ah, though I don't let it get below 15% SOC or -150 to -170 AH.
This is a hybrid system, as my old SLA 8-D's are connected in parallel.

 

[sailing gal]

I am currently installing 400 Ah of LFP batteries with. It consists of 2 200Ah batteries with BMS that documentation says has charging of 40 Ah. My engine and alternator are set up as follows. I have a completely isolated AGM start battery, with its own ON/Off switch. Then I have the house bank with its own on/off switch. Engine charges both banks. Typically, I am sailing with both batteries in the on position. I also have solar panels and a windgen that only charge the house bank. I have a pre 2017 100 A Balmar alternator. I have a new battery charger that has a FLP setting. So, my understanding from this discussion is that my AGM starter battery basically protects my alternator from overheating if a BMS shut off of the LFPs should occur. I am also considering adding a resistor wire to the alternator set-up to keep the output a bit lower. (I also have a serpentine belt kit on my yanmar- great improvement). So, am I correct in this? Should I bother installing the resistor? Is the alternator protected due to the AGM starter battery in the system?

 

[John Simmons]

Your understanding is WRONG.

The AGM battery will protect the electrical system and the alternator diodes in case the BMS of the lithium iron phosphate batteries disconnects them.

Do you have an external voltage regulator with the Balmar Alternator? Do you have an alternator temperature sensor? You need both. You also need to program the external regulator to the recommended settings for Bulk/Absorb/Float of your battery manufacturerer.

If you do not have a temperature sensor you risk burning up your alternator.

I would advise you to contact Balmar Technical Support. They are super and will not give bad advice. Submit a ticket from their website

Home - Balmar

Balmar has been serving the Recreational Marine Industry for over 30 years. We supplying Alternators, DC Charging Products, and Battery Monitors

balmar.net

john.