Opinions on new LiFePO4 housebank install

[Captain Bill]

Looking for a little help on my new lithium house bank installation. My Concorde Lifelines have bit the dust after only 3.6 years with more than half of them sitting at float due to repairs and covid and knee issues cramping my cruising. I am making the jump to LiFePo4 for my house bank. The start bank was replaced last year and will remain AGM. I currently have three charging sources connected to my house bank. A Morningstar Tristar mppt-60 connected to two 320w solar panels, a Xantrex 3000W inverter/charger (150a charge) and my Yanmar (Hitachi) 55a alternators from my two 3jh3ce engines. The start batteries are charged via an ACR.


When off the dock my primary charging source will be the solar panels. The inverter charger is connected to a 5kw genset so can be used for bulk charging when needed. The batteries I have purchased have built in BMSs so no real customization is available. I can customize the settings on the inverter/charger and the solar controller so I'm not terribly concerned about that. My concern is that the dumb regulators on my alternators. The first concern is that the batteries will overload the alternators, but the Hitachis have thermal overload protection and reduce their voltage output fairly rapidly to around 13.4V, but even at this voltage a depleted lithium bank will still draw a lot of current. The second concern is that a sudden cutoff of charging from the internal battery BMSs will blow the diodes in the alternator. My primary use of the engine alternators will be to power house loads at night(night being defined as anytime the solar panels cannot carry the house load) while underway on engines. With refrigeration, radar, AIS, lights, MFD etc. my load can be into the low 20 amps. I have had occasion to keep at least one engine running on a long overnighter in the winter months and no wind. So I'm sure it will occur again. The problem is that if the lithium's are fully charged these things will keep on pumping out their 14.2V for hours on end which will damage the lithiums. This is all based on what I've read on the internet, which is sometimes worth what you pay for it. My current thought is to move the engine alternators to the engine batteries and connect them to the lithium side through a Victron Orion-TR smart charger. This would limit the maximum load on the alternators to 30a and I can set the charging parameters to the float voltage of the lithiums so the alternators can carry the house load without damaging the lithiums. It also solves any overdraw on the alternators and unexpected charging cutoff problems. The lithium batteries will be 3 100ah 12v nominal batteries connected in parallel, so the odds of all three BMSs cutting off charging is pretty low, but possible since some of my DC loads are inductive and can throw voltage spikes.


I'm not looking to start another big lithium thread. As I have read a lot of them though only a bit of the huge one. Just looking for input on my plan to move the alternators to the start battery side and install the Victron smart charger. I forgot to say I would be disconnecting the ACR. Does anyone think that this is too much or not enough? Also any opinions anything else I should do.


Thanks


Bill

[SVDontpanic]

This is similar to what I am doing with my conversion to LiPo4.
Engine Alternator is connected to the starter battery, the house bank is charged via 2x Orion-TRs. This protects the alternator from a BMS disconnect.

The BMS on the batteries is there to protect the batteries. Set your various charging devices to stop charging before the BMS would do a high voltage cut off (check with your battery manufacture). I have mine set to charge up to 14v and float at 13.2v (I think, maybe at 13.5v, I'm not at my boat right now to verify). This way the charging will stop before the BMS stops it for you.

Everyone will have a different take on what you should set the voltages at.


One thing I added to my configuration which you did not mention was a Balmar smart regulator. You may want to look into adding one. Also you can parallel multiple Orion-TRs to increase the charge rate, one of the advantage of lithium, they will take all you can give them. With 3x 100ah batteries you could easily charge them at 150ah (0.5C), but confirm with your battery manufacture.

[ThereAndBack]

Your proposal mimics my current setup that has been running for about 3 years without plugging in. Works great. Enjoy the lithium batteries. I was blown away after many years of lead acid.

[rsvmille]

Sounds like a good plan. Might consider a Sterling Battery-to-Battery charger which is designed for this purpose.

Not just a pitch, I came because interested to help, and Sterling has a great product with good support. But in case you do consider this I do have a new 60amp waterproof unit that I won't be using and will be selling.

I know you stated the AGM start will stay. In case you are buying new, an option to consider might be to use starter rated LiFePo4s like the Dakota starter and switch the alternators to smart regulators like the Balmars and a simpler relay between the banks for other charging sources (that don't support multiple banks).

[Captain Bill]

Originally Posted by SVDontpanic

This is similar to what I am doing with my conversion to LiPo4.
Engine Alternator is connected to the starter battery, the house bank is charged via 2x Orion-TRs. This protects the alternator from a BMS disconnect.

The BMS on the batteries is there to protect the batteries. Set your various charging devices to stop charging before the BMS would do a high voltage cut off (check with your battery manufacture). I have mine set to charge up to 14v and float at 13.2v (I think, maybe at 13.5v, I'm not at my boat right now to verify). This way the charging will stop before the BMS stops it for you.

Everyone will have a different take on what you should set the voltages at.


One thing I added to my configuration which you did not mention was a Balmar smart regulator. You may want to look into adding one. Also you can parallel multiple Orion-TRs to increase the charge rate, one of the advantage of lithium, they will take all you can give them. With 3x 100ah batteries you could easily charge them at 150ah (0.5C), but confirm with your battery manufacture.

I looked at the Balmar smart regulator and I would have to disassemble and modify my Hitachi's as well as buy the regulators. It's a lot of expense just to cover house loads while motoring. My panels were keeping my AGMs pretty well topped up by noon and I would think that the more efficient LifePO4s will be better than that and in even a severely discharged scenario I should be able to get them back to full charge in just 2 hours of genset time.



I checked with the battery manufacturer yesterday an .5C is fine, .2C is optimal and 1c is max. The Solar .s right at .2C Max which I have never actually seen though I've gotten close, but one is still carrying house loads so effectively probably about .1c average. I think that I once saw 37 amps net to the batteries after a cloudy day. Most of the time things were pretty well throttling back after about 10:30 as I was usually down about 17% overnight.

[SOLAR SUPPORT]

I have searched and read a lot about Lithium batteries to be used on boats in forums and articles published on the İnternet. I want to tell you first that I don't want to lead you to some area of products or any influence to your future decision to renew or upgrade of your battery bank. I am a retired mec. engineer.

I continue to use my AGM household batteries in my boat in its 6th year. In my opinion, the best of the Lead-acid generation are AGMs. Upgrading from Lead-Acid to Lithium seems like a brilliant idea nowadays. Lithium technology has come with great advantages, especially its use in automobiles is very common.

I doubt that the 2000 promised number of healthy life cycles, which is the biggest feature of this technology, will be benefited from on boats, because a very sensitive charging regime is required for Lithium battery charging. There is the problem of how and with which charging source this charging regime can be supplied safely while boats are at sea. Because of these charging issues, the promised life cycles will be reduced when Lithium batteries are used on boats. How much will this decrease be? That is the question.

Even though Lifepo4 class batteries have been developed for more flexible charging properties than Lithium batteries, they can prove their service life warranty on boats after many years. In addition to sensitive charging requirements, leaving Lithium batteries fully charged for a long time also shortens their service life. I can see that if we cannot provide the necessary conditions for the performance and the promised healthy cycle life of lithium batteries, our life expectancy for these batteries will not be realized. The fact that the infrastructure changes required to be made in the charging infrastructure as well as the Lifepo4 batteries are quite costly increases the financial risk taken for this upgrade. For these reasons, I am considering replacing my AGM batteries with classical Lead-acid AGMs when their life is over for now.

[more]

you forget Electric Potential Difference and Ohms Law + internal resistance in cable and cell

but simple alternator is ideal charging source for lifepo4,and alternator can 100% charge

for example you have alternator 3000A or grid (million bilion Amper potential for sucks)
from alternator to lifepo4 you have 5 meter and cable 35 mm2
resistance 2.5 mohms
battery have 0.5 mohms (i don't think so you buy A class from factory because this cell reserved for 100+ milion€ buyer car manufacture)

in real-world max current flow is 3-4A
I = VR=14.2 volt
3 mohm= 4.7333333333333 ampere (A)
P = V2R= (14.2 volt)2
3 ohm= 67.213333333333 watt (W) max

lithium battery is only full charged on 14.4V
i on 5 meter 95mm tined cable + 1.2 meter 35mm cable have only 14.05 V
battery is Winston cell 200A

[more]

if your charger or alternator set to over 14.6V (on busbar cell) this need attention

[Hermia II]

This is what I have installed after A LOT of investigation and discussion. I think it is good to know that with properly managed LiPo4 sources, you are into completely new territory. It will be very good, but it is definitely costly and complicated. Check out my wiring diagram and compare to the old stuff. All comments are very much appreciated.

[more]

again check with multimeter voltage on the alternator for example 14.4
check again on your full charged start battery 14.1 V you have some voltage lose on cable under 3% is good

14.1 /4 = 3,52 sh... you can full charge your lifepo4 battery you are on 95%
now 14.1 - 13.5 = 0.6V 1 ohm
current flow on voltage difference
use this calculator
https://ohmslawcalculator.com/ohms-law-calculator

if you more scare use diode-based isolator and you have 0.5V voltage drop and your lifepo4 battery never be 100% charged ,battery be idealy charged 85-90% and you have almost double lifespan of your battery

[smac999]

get rid of the acrs. connect the alternators direct to start batteries if not already. buy two victron orion smart 30a dc to dc chargers. one for each engine battery to house. 30a won't cook your small alts. and that way won't blow up the alt if the bms opens.

actually do you only have one start battery for 2 engines? do no normally run both or only 1 at a time? with one battery you may only want one dc to dc. otherwise with one engine it will try to pull 60a out of one alt.

ideally you'd have 2 start batteries with a dc to dc from each. then each alt could put out 30a


the sterling dc to dc is garbage.

balmar regs are about 2 months backorder right now. we can't buy them.

[tomsnrg]

Originally Posted by Captain Bill

Looking for a little help on my new lithium house bank installation. My Concorde Lifelines have bit the dust after only 3.6 years with more than half of them sitting at float due to repairs and covid and knee issues cramping my cruising. I am making the jump to LiFePo4 for my house bank. The start bank was replaced last year and will remain AGM. I currently have three charging sources connected to my house bank. A Morningstar Tristar mppt-60 connected to two 320w solar panels, a Xantrex 3000W inverter/charger (150a charge) and my Yanmar (Hitachi) 55a alternators from my two 3jh3ce engines. The start batteries are charged via an ACR.


When off the dock my primary charging source will be the solar panels. The inverter charger is connected to a 5kw genset so can be used for bulk charging when needed. The batteries I have purchased have built in BMSs so no real customization is available. I can customize the settings on the inverter/charger and the solar controller so I'm not terribly concerned about that. My concern is that the dumb regulators on my alternators. The first concern is that the batteries will overload the alternators, but the Hitachis have thermal overload protection and reduce their voltage output fairly rapidly to around 13.4V, but even at this voltage a depleted lithium bank will still draw a lot of current. The second concern is that a sudden cutoff of charging from the internal battery BMSs will blow the diodes in the alternator. My primary use of the engine alternators will be to power house loads at night(night being defined as anytime the solar panels cannot carry the house load) while underway on engines. With refrigeration, radar, AIS, lights, MFD etc. my load can be into the low 20 amps. I have had occasion to keep at least one engine running on a long overnighter in the winter months and no wind. So I'm sure it will occur again. The problem is that if the lithium's are fully charged these things will keep on pumping out their 14.2V for hours on end which will damage the lithiums. This is all based on what I've read on the internet, which is sometimes worth what you pay for it. My current thought is to move the engine alternators to the engine batteries and connect them to the lithium side through a Victron Orion-TR smart charger. This would limit the maximum load on the alternators to 30a and I can set the charging parameters to the float voltage of the lithiums so the alternators can carry the house load without damaging the lithiums. It also solves any overdraw on the alternators and unexpected charging cutoff problems. The lithium batteries will be 3 100ah 12v nominal batteries connected in parallel, so the odds of all three BMSs cutting off charging is pretty low, but possible since some of my DC loads are inductive and can throw voltage spikes.


I'm not looking to start another big lithium thread. As I have read a lot of them though only a bit of the huge one. Just looking for input on my plan to move the alternators to the start battery side and install the Victron smart charger. I forgot to say I would be disconnecting the ACR. Does anyone think that this is too much or not enough? Also any opinions anything else I should do.


Thanks


Bill

Just my two cents from one installation built as you proposed. The Victron Orion Tr Dc-Dc 30A exists commercially in an early version which will crank out more than 30A. The latest one is limited to 30A max and offered in exchange free of charge by Victron, (quite good customer service). The converter has about 80% efficiency and will get hot. I would consider forced ventilation, you need to find a suitable place to install it. The TR is also not provided with the VE-Bus and could be better integrated in the Victron-Ecosystem. Configuration is easy via App. The owner is happy with this system and has finally a solution to reliably handle 2 different voltage levels on board. Fotovoltaics/wind go direct to the lithium-bank.

[Britishsea]

[QUOte


I'm not looking to start another big lithium thread. As I have read a lot of them though only a bit of the huge one. Just looking for input on my plan to move the alternators to the start battery side and install the Victron smart charger. I forgot to say I would be disconnecting the ACR. Does anyone think that this is too much or not enough? Also any opinions anything else I should do.


Thanks


Bill[/QUOTE]

I spent some time putting LFP in my boat this year.

Your plan looks good to me. The only downside is that 30amps of charging of LFP from the alternators (via the Victron Orion DC-DC) is pretty low.

SMC999 seems to have good solution for a small additional cost, if you have dedicated start batteries for each engine.

I also have the Victron Orion DC-DC charger. One item to consider, while it's generally very configurable on the charge side, the one item you can't change is its charge current output. So it will pull around 36amps from your alternator to put 30amps into your LFP battery. If you are running only one engine at idle RPM for a "night" recharge, that may stress your 55amp Hitachi alternators. Victron also make an 18amp version.

I think it was a big miss on Victron's part not to be able to customize the output current, so customers can tune for their circumstances.

[Pete7]

Originally Posted by Britishsea

I also have the Victron Orion DC-DC charger. One item to consider, while it's generally very configurable on the charge side, the one item you can't change is its charge current output. So it will pull around 36amps from your alternator to put 30amps into your LFP battery. If you are running only one engine at idle RPM for a "night" recharge, that may stress your 55amp Hitachi alternators. Victron also make an 18amp version.

I think it was a big miss on Victron's part not to be able to customize the output current, so customers can tune for their circumstances.

One thing I have been playing with is to switch the Orion into power supply mode and then drop the voltage. This also drops the amps down enabling a lower charge, particularly if you are on board using some of that supply to run domestics too. A supply of 13.8v with a couple of Ah for domestic gives us 5A to the LFP.

We have a 3" hole behind the Orion to increase cool air and deal with the heat issue. However, I also have a PC fan to install.

Pete

[smac999]

the victron dc to dc will drop the amps to maintain the voltage on the start battery.

IE if you set the voltage cut off to 13.2v which I think is the default for smart alt. the start battery will not go under that. so if drawing 30a is more then the alt can put out, causing the start battery to drop below 13.2v the charger will claw back. and maybe only output 20a.

this is really handy when you have a bunch of them. I put 5 on one boat. 90a from one engine and 60a from the other. at idle they will just claw back the current.

unlike the mastervolt dc to dc which will just cycle on and off at full amps if the alt can't keep up.