LiFePo house battery

[Delfin]

Now I understand. At least partially - there are some apples and oranges here. When you say 3-stage regulators, I assumed you meant regulators for alternators, not a generic function of a 120/240VAC inverter/charger.

Agree that virtually all boats these days have 3-stage 120/240VAC inverter/charger. chargers........for shore power/generator power. Though LFP settings are still pretty new. As of a year ago, many Xantrex models were not compatible with LFP but were indeed 3-stage.

In looking at the Xantrex model, they may not have a factory installed setting labeled "Lithium", but like every other smart regulator they allow you to set the voltage for bulk, absorption time and float, so could certainly be used for LFP. They wouldn't be mu first choice, but if Xantrex is what you have, that won't stop you from using it for LFP. The same technology is used in smart chargers, which in my experience are also programmable so no difference there.

But importantly for this discussion, on-grid chargers are typically included in an inverter/charger device and direct attached to a battery bank - cable distance is minimized so agree, thats not a problem of ciurse. Until fairly recently, few boats had more than about 75a of charging power, even now 120a is at the upper end for most 3kw watt inverter/chargers, likely the most common size for new installs on the typical TF boat.

What I was referring to was off-grid/underway - alternator driven. While not rare, going above 120a on a single Alternator was not overly common but is becoming much more so with acceptance of LFP. External regulation remains rare but growing. Expectation for off-grid power is growing fast so battery banks are getting bigger and need for power generation to suit (the crux of TTs post).

Bottom line is TT put it well but I'll rephrase slightly. If goal is like-for-like swap of watts (power), you're right - no need for massive upgrades (though I still disagree about need for DC-DC charger for chemistry - and i disagree with your anslysis of the Victron quote where you conclude a 3-phase charger is superfluous: if the start battery (FLA/AGM) is charged from the LFP house, giving it 3-stage charge profile is still desired). But that's not what's driving people to change- they want more power and that requires more robust infrastructure.

Peter

Increasing charging capacity of an existing system is optional for LFP, not a required change to make to do the upgrade. And if you are correct that "external regulation" of alternator output is "rare", then the majority of cruising boats are charging their deep cycle batteries using technology that will significantly shorten battery life for the reasons given above. I doubt it is rare, but if so, regardless of whether one upgrades to LFP that should be changed by those cruisers.



If you aren't off grid very often, then LFP is a waste of money unless its weight advantage is critical. Or, if the vessel has a quiet night time low kw generator you probably don't need LFP either because the ridiculously long time to drive an LA battery to 100% charge is immaterial since the small genset runs for hours anyway. On the dc - dc charger, I've found that as a practical matter, having a single smart regulator setting tuned to LFP works just fine for a starter LA bank, so a dc - dc charger would be useless. I have my Balmar alternator regulator and Trace charger set to pump out 29.2 volts to the LFP, per the manufacturer's specification, with a 5 minute absorption time and float set to what the LA battery prefers. This last is because I never float my LFP - when they're full, I simply use the typical rotary switch you find in most boats to take the LFP off line and direct float current to the LA.


I think what you are suggesting is that if you want to upgrade to LFP many may end up doing upgrades to their entire system, and I think that is true to take advantage of LFP's higher charge current acceptance rate. But that is not the same as communicating to people that they have to do the upgrade to use LFP, because they don't. I added chargers to my system to increase charging capacity to 200 amps, but didn't need a bigger alternator since I already have a high output, de-rated by 30%. But if I was happy to charge my LFP at 100 amps in 3 hours instead of 6 hours to fully charge the AGMs I replaced, I could have done so without changing ANYTHING. I wanted to take advantage of LFP, so added charging capacity.

 

[Ka_sea_ta]

I think this is worth expanding on.


LFP has some differences due to battery behavior of the chemistry.


LFP introduces an BMS which under fault conditions will disconnect the battery. You need to ensure that won't cause damage to other parts of your electrical system.


BMS Disconnect: This is unique to LFP, no doubt. But it's also no different than a fuse blowing and disconnecting your house bank. In the later case we live with the risk, but in the former case we get all twiterpated about it. I think a really important thing to remember is that a BMS disconnect is not an end of charge indicator. It's a fault indicator. If you are charging anywhere near the BMS disconnect point, stop doing that. If your BMS is disconnecting, figure out why and fix it. Now I am NOT saying you shouldn't protect against a disconnect, just trying to emphasize that it's a fault condition, not normal operation. With that in mind, there are a variety of solutions, my own favorite being use of a disconnect warning signal from the BMS to turn off the alternator. This is increasingly available, even from so-called drop-in batteries.

The frequency of a BMS fault is something that only experience with this technology will determine. From my perspective the more sophisticated the BMS the more it is likely to disconnect. I.E. look at the Epoch battery review that Will Prosse did, There are thermistors on the MOS Fets, terminal posts, battery pack and an environmental one thrown in for good measure. Any one of these exceeds it's rated temp and it immediately disconnects the charging. I have no idea what other conditions will cause a disconnect but I'm pretty there are several more. The BMS is there to protect the battery not the charging source, While I'm not sure I suspect most electrical powered battery chargers will tolerate a sudden disconnect when operating.

An alternator even with a smart regulator not so much. Wakespeed may be the exception.



Question: The batteries are connected through a can buss. If one shuts disconnects do they all follow suit? If not then with multi batteries a sudden disconnect is no big deal.

 

[CMS]

round and round we go.

If only a DC2DC charger can have an input from a non external regulated ALT, then the DC2DC charger can be the regulator for the chosen battery bank and ALT.
Too simple and already said cannot do that, it must come off a start battery.

TT makes a good point that it is the high rate of charge a large bank demands that can fry an alternator regardless of chemistry.

Thy need the buffering filtering of a 12V battery.. Charlie Sterling has been working on this but they are not yet available in the US. Having a lead acid buffer/start/reserve battery is cheaper too...

https://sterling-power.com/products/alternator-linearisation-device-17-5v-70f-ald-17500

 

[SteveK]

Thy need the buffering filtering of a 12V battery.. Charlie Sterling has been working on this but they are not yet available in the US. Having a lead acid buffer/start/reserve battery is cheaper too...

https://sterling-power.com/products/alternator-linearisation-device-17-5v-70f-ald-17500

Good news.

 

[Cargile]

Two diagrams are attached...................

View attachment 137980

View attachment 137981

Thanks very big. They do help. I do not have a solar panel input. In your diagrams could I put my engine alternator where your solar panel is as a DC input? Sad news about Renogy. I was looking at them because of price.

 

[SteveK]

Thanks very big. They do help. I do not have a solar panel input. In your diagrams could I put my engine alternator where your solar panel is as a DC input? Sad news about Renogy. I was looking at them because of price.

I do not understand why, but no, do not connect ALT directly, all sources say it must come from another battery that is direct charged from ALT.

 

[Cargile]

I do not understand why, but no, do not connect ALT directly, all sources say it must come from another battery that is direct charged from ALT.

Thanks again Steve. No mater why but I do not have a solar 12 vdc input. Unless you are implying everyone in Florida has solar power. Anyhow, an alternator is also 12 vdc input. That is why I asked could it replace the solar (which I don't have) input. I am sorry but the rest of your statement is not clear to me. I am going to leave it alone for now.

 

[SteveK]

Thanks again Steve. No mater why but I do not have a solar 12 vdc input. Unless you are implying everyone in Florida has solar power. Anyhow, an alternator is also 12 vdc input. That is why I asked could it replace the solar (which I don't have) input. I am sorry but the rest of your statement is not clear to me. I am going to leave it alone for now.

I never said solar, that was Peter, I was only replying to your ask about ALT direct connection. I will add no point in getting the dual input if you do not have plans for a second source like solar for which it is designed.

 

[mdstrum]

Instead of DC to DC charge (which I have in my RV with battleborn Lithium setup, on our boat we use a Balmar Charge Controller. This can programmed to Litium spec, and I believe they make a duel out if need to charge the start and house at the same time.
DC to DC moves current from the start when full to House, personally it produces alot of heat in our RV and I plan to to Balmar or maybe this from battleborn in the RVhttps://battlebornbatteries.com/product/ws500-advanced-alternator-regulator/

 

[Statistical]

Am I the only one that thinks its ridiculous that the latest bleediang edge battery technology can't be connected to any system without major upgrades and hardware replacement? Could the BMS not simply be programmed for the installation type and be good to go? I mean, they're smart enough to know when to disconnect due to over voltage, under temp, over temp, over current but can't figure out to reduce input current when they reach full charge? I'm hoping the next generation batteries are smarter than this generation.

James

It isn't a limitation of the BMS or the new battery. It is a limitation of assumptions made in the alternator. Most alternators can't supply peak power for an extended period of time. With modest sized lead acid batteries this isn't a problem. As Soc % rises the charge acceptance of the battery decreases significantly. So a 200A alternator will not output 200A for long. The battery ends up being the bottleneck.

With LFP especially large LFP banks they can pull down that 200A continually for potentially hours. The alternator haven't been designed and built before LFP existed assumes lead acid and will get destroyed in the process.

The other issue is the BMS on an LFP battery may need to disconnect it in a fault condition to avoid catastrophic cell damage possibly even fire or rupture. The load disapearing on a loaded alternator will cause damage. Note this while very unlikely is no different than manually disconnecting a lead acid battery. The same damage would occur. The big difference here is the potential for it to happen without manual action.

 

[CarlF]

Another thing to consider is that many insurance companies do not want owners installing lithium batteries.

If you tell your insurance company, they will almost certainly ask for the name of the ABYC electrician who did the install. If you don’t tell the insurance company, they may refuse a future claim.

So instead of trying to spec this yourself with help from the internet - I’d find an electrician with lots of marine lithium install experience.

When you get the quote with their labor, you’ll probably stick with with what you have now

 

[Simi 60]

Another thing to consider is that many insurance companies do not want owners installing lithium batteries.

If you tell your insurance company, they will almost certainly ask for the name of the ABYC electrician who did the install. If you don’t tell the insurance company, they may refuse a future claim.

So instead of trying to spec this yourself with help from the internet - I’d find an electrician with lots of marine lithium install experience.

Likely only a problem in America
Much of the world wouldn't know of or care what abyc is.

When you get the quote with their labor, you’ll probably stick with with what you have now

Or, if like us the boat is set up well from day 1 , it'll be not much more than reprogramming to the lifepo4 charge profile.
20 minutes.

 

[Simi 60]

Bolded, yes I have that same thought.

Killed two Alternators charging AGM? I wonder if it was due to the size of the bank you have, smaller bank AGM maybe OK for same ALT.
A lot to digest.

It was 880ah (440ah usable) @ 24v for the AGM

Now have 840ah @ 24 of lifepo4

And the bolded bit

My way of thinking is a DC to DC charger will cause the alt to do the same

I could not see anywhere in this thread where this was addressed?

Recap: if I have a 40 amp alt (as we do) and a 30amp 24v dc-dc charger from starts to big battery bank, surely that'll cause the alt to run hard enough that the smoke escapes.

 

[sunchaser]

Our insurance company has no problem with LFPs. I believe that the “myth” is possibly associated with below par overall electrical systems that predate a Li battery addition.

 

[guy with a boat]

Another thing to consider is that many insurance companies do not want owners installing lithium batteries.

If you tell your insurance company, they will almost certainly ask for the name of the ABYC electrician who did the install. If you don’t tell the insurance company, they may refuse a future claim.

What insurance companies? Is this from actual experience? I haven’t found this to be the case at all. Any specific examples that you can share would be helpful.

 

[SteveK]

It was 880ah (440ah usable) @ 24v for the AGM

Now have 840ah @ 24 of lifepo4

And the bolded bit

My way of thinking is a DC to DC charger will cause the alt to do the same
I could not see anywhere in this thread where this was addressed?

Recap: if I have a 40 amp alt (as we do) and a 30amp 24v dc-dc charger from starts to big battery bank, surely that'll cause the alt to run hard enough that the smoke escapes.

bolded. It has not been clear how an ALT can be spared with DC2DC feeding the house off the start. The load (house) will still be looking for a charge keeping ALT running longer is what I keep seeing. Mentioned was to have a temp sensor on ALT. Without an external regulator I have not seen how a temp sensor would work.
Yet, a few are charging LFP direct from an unregulated ALT.

 

[CarlF]

What insurance companies? Is this from actual experience? I haven’t found this to be the case at all. Any specific examples that you can share would be helpful.

I was shopping for insurance last year (stayed with my current). If I remember correctly both Chubb and Markel asked if lithium batteries were installed by a licensed electrician and wanted the installer’s name.

 

[Statistical]

bolded. It has not been clear how an ALT can be spared with DC2DC feeding the house off the start. The load (house) will still be looking for a charge keeping ALT running longer is what I keep seeing. Mentioned was to have a temp sensor on ALT. Without an external regulator I have not seen how a temp sensor would work.
Yet, a few are charging LFP direct from an unregulated ALT.

Yeah DC to DC converter can be an option for those who have a high power (80A+) alternator but one which is LFP unaware.

For the OP with tiny stock 40A alt the best solution is just a new high power FFP aware alternator likely one with external regulation put in at the same time as the LFP bank.

 

[guy with a boat]

I was shopping for insurance last year (stayed with my current). If I remember correctly both Chubb and Markel asked if lithium batteries were installed by a licensed electrician and wanted the installer’s name.

Interesting. I have 2 boats insured with Chubb and wasn’t asked either question in either instance. The question was also not asked by any other company that quoted the renewals. There is no exclusion or condition in the Chubb policy regarding LFP.

Seems unlikely that an insurance underwriter would have the slightest idea who the installers are in the huge range of geography that they serve.

 

[Statistical]

Interesting. I have 2 boats insured with Chubb and wasn’t asked either question in either instance. The question was also not asked by any other company that quoted the renewals. There is no exclusion or condition in the Chubb policy regarding LFP.

Seems unlikely that an insurance underwriter would have the slightest idea who the installers are in the huge range of geography that they serve.

Also not even clear an generic electrician would have any clue about best practices when it comes to installing LFP on a marine vessel. Electricians are use to working on land and following the NEC (National Electric Code) which is decidedly less than helpful on proper install of LFP batteries in things that float.

 

[CarlF]

Also not even clear an generic electrician would have any clue about best practices when it comes to installing LFP on a marine vessel. Electricians are use to working on land and following the NEC (National Electric Code) which is decidedly less than helpful on proper install of LFP batteries in things that float.

I believe they were looking for an ABYC certified electrician. Can’t remember the details of the form but Chubb isn't stupid.

Of course, not all ABYC certified electricians know much about lithium. I still see an awful lot of undersized cables, unequal length cables, and ANL fuses in very expensive lithium installs.

 

[BruceK]

Interesting...Seems unlikely that an insurance underwriter would have the slightest idea who the installers are in the huge range of geography that they serve.

Imo,more interested who to pursue for any associated fire than installer expertise.

 

[Delta Riverat]

I'm going LiFePO4 for house.

Last half day adventure left batteries at 12.5. In house charger did nothing. While looking the 4D house batts are from 2017. And cheapies too.

Going to remove the Intellipower charger, the west marine 10 amp and make sure to isolate the engine batts (3) from the house batts (2)

Going with Xantrex pro mariner 3KW, and (2) 300 AH Li Time batts with 200A BMS.

The three starter bats will remain lead acid and be dock serviced by a Xantrex 40A 3 bank charger.

Lotta wiring to do which I'm not scared of. The scary part is getting those 2 lead acid batteries out of the boat. I could hurt myself real bad. Not worried about the new batts, 60 pounds each. But I think I'll hire some help for the old ones.

 

[Hyperion]

Another thing to consider is that many insurance companies do not want owners installing lithium batteries.

If you tell your insurance company, they will almost certainly ask for the name of the ABYC electrician who did the install. If you don’t tell the insurance company, they may refuse a future claim.

So instead of trying to spec this yourself with help from the internet - I’d find an electrician with lots of marine lithium install experience.

When you get the quote with their labor, you’ll probably stick with with what you have now

Maybe with Lithium Ion but not Lithium Iron Phosphate. Those two things are worlds apart when it comes to safety. One can sustain violent combustion even when not fed with oxygen, as in under water. The other smokes and heats slightly after catastrophic failure and will respond to oxygen displacement like halon systems.

"Safety Advantages Of Lithium Iron Phosphate:
Manufacturers across industries turn to lithium iron phosphate for applications where safety is a factor. Lithium iron phosphate has excellent thermal and chemical stability. This battery stays cool in higher temperatures. It is also incombustible when it is mishandled during rapid charges and discharges or when there are short circuit issues. Lithium iron phosphate does not normally experience thermal runaway, as the phosphate cathode will not burn or explode during overcharging or overheating as the battery remains cool.

However, the chemistry of lithium-ion does not have the same safety advantages as lithium iron phosphate. Its high energy density has the disadvantage of causing the battery to be unstable. It heats up faster during charging as a lithium-ion battery can experience thermal runaway."

 

[twistedtree]

Maybe with Lithium Ion but not Lithium Iron Phosphate. Those two things are worlds apart when it comes to safety. One can sustain violent combustion even when not fed with oxygen, as in under water. The other smokes and heats slightly after catastrophic failure and will respond to oxygen displacement like halon systems.



"Safety Advantages Of Lithium Iron Phosphate:

Manufacturers across industries turn to lithium iron phosphate for applications where safety is a factor. Lithium iron phosphate has excellent thermal and chemical stability. This battery stays cool in higher temperatures. It is also incombustible when it is mishandled during rapid charges and discharges or when there are short circuit issues. Lithium iron phosphate does not normally experience thermal runaway, as the phosphate cathode will not burn or explode during overcharging or overheating as the battery remains cool.



However, the chemistry of lithium-ion does not have the same safety advantages as lithium iron phosphate. Its high energy density has the disadvantage of causing the battery to be unstable. It heats up faster during charging as a lithium-ion battery can experience thermal runaway."

I hate to say it, but that’s a quote from someone who doesn’t know what they are talking about, and is just regurgitation what they have heard from others who don’t know what they are talking about.

As soon as someone starts comparing LFP LiFePo4 with “lithium ion”, you know they are just parroting. LiFePo4 IS Lithium Ion. It’s just a type of Lithium Ion, not something different from lithium Ion. It’s like saying dogs are better than animals, when what you mean is that dogs are better than cats. Both are animals, just different kinds of animals with very different characteristics. His fundamental points are correct, but so muddled up in basic misunderstandings that it really doesn’t help educate people, and just propagates misunderstanding.

 

[Don L]

every one of these threads in every forum goes the same way

 

[Hyperion]

I hate to say it, but that’s a quote from someone who doesn’t know what they are talking about, and is just regurgitation what they have heard from others who don’t know what they are talking about.

As soon as someone starts comparing LFP LiFePo4 with “lithium ion”, you know they are just parroting. LiFePo4 IS Lithium Ion. It’s just a type of Lithium Ion, not something different from lithium Ion. It’s like saying dogs are better than animals, when what you mean is that dogs are better than cats. Both are animals, just different kinds of animals with very different characteristics. His fundamental points are correct, but so muddled up in basic misunderstandings that it really doesn’t help educate people, and just propagates misunderstanding.

I guess I need to do more research as I though the battery chemistry and it's reactive properties were significantly different from a combustion point of view.

 

[twistedtree]

I guess I need to do more research as I though the battery chemistry and it's reactive properties were significantly different from a combustion point of view.

LFP is indeed less dangerous and more stable than NMC, or LCO, or a variety of other lithium
Ion variants. But they are ALL lithium ion batteries.

 

[Hyperion]

Live an learn. Thanks for letting me know Twistedtree. I have been walking around thinking I knew and did not. Not A state I like. So here is what I found digging deeper than the "Battery Experts on Youbes":

As you said, they are all Lithium iOn batteries and I though LifePo was not. As far as the Thermal Runaway characteristics of the most common chemistries are:

• Lithium Cobalt Oxide(LiCoO2) — LCO
  150°C (302°F). Full charge promotes thermal runaway
  
  
• Lithium Manganese Oxide (LiMn2O4) — LMO
  250°C (482°F) typical. High charge promotes thermal runaway
  
  
• Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
  210°C (410°F) typical. High charge promotes thermal runaway
  
  
• Lithium Iron Phosphate(LiFePO4) — LFP
  270°C (518°F) Very safe battery even if fully charged

Source

 

[Blues]

I'm going LiFePO4 for house.

Last half day adventure left batteries at 12.5. In house charger did nothing. While looking the 4D house batts are from 2017. And cheapies too.

Going to remove the Intellipower charger, the west marine 10 amp and make sure to isolate the engine batts (3) from the house batts (2)

Going with Xantrex pro mariner 3KW, and (2) 300 AH Li Time batts with 200A BMS.

The three starter bats will remain lead acid and be dock serviced by a Xantrex 40A 3 bank charger.

Lotta wiring to do which I'm not scared of. The scary part is getting those 2 lead acid batteries out of the boat. I could hurt myself real bad. Not worried about the new batts, 60 pounds each. But I think I'll hire some help for the old ones.

I hired someone to hump the old batteries out of there, not worth messing with. I purposely went with 100 amp liths because they are only 26 pounds each and it’s too cold around here to leave them in for the winter. Now it’s an easy job to pop them out.

The cabling was slow going.