LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[OceanPlanet]

Originally Posted by Hoopla

That consumer 1 1/2 star or F Rating for that Smart Battery crowd probably doesn't even include those poor people wondering why they keep melting small case auto style alternators.

These Drop In LFP merchants are giving LFP a bad name. Something needs to be done about it by the marine industry.

New ABYC standards will address Li very well, including drop in. However the process of creating those standards has been a long one....it's a lot of work. Some very good people involved, especially Nigel Calder. Don't know what ABYC would do without him...

[jkleins]

Originally Posted by OceanPlanet

New ABYC standards will address Li very well, including drop in. However the process of creating those standards has been a long one....it's a lot of work. Some very good people involved, especially Nigel Calder. Don't know what ABYC would do without him...

Can you expand upon the problems with the drop in batteries a bit? The comments that came after yours assumed too small an alternator or lack of adequate charging source but is there more?
I was assuming that anyone looking at lithium would already have a large alternator that could handle large loads and a regulator that was adjustable to handle whatever the recommended settings of the battery would be. The integrated BMS seems like a good idea in that situation making them similar to the Firefly batteries.
Is there something particular about the integrated BMS or just the particular Smart Battery that makes it undesirable?

Jim

[john61ct]

Originally Posted by jkleins

The comments that came after yours assumed too small an alternator or lack of adequate charging source but is there more?
I was assuming that anyone looking at lithium would already have a large alternator that could handle large loads and a regulator that was adjustable to handle whatever the recommended settings of the battery would be. The integrated BMS seems like a good idea in that situation making them similar to the Firefly batteries.
Is there something particular about the integrated BMS or just the particular Smart Battery that makes it undesirable?

The problem with alternators is not large vs small, but proper VR handling of temps rising due to the bank pulling high current rates.

An external VR like Balmar MC-612 does proper staged charging, and when the alt gets hot will reduce current output but keep voltage at the (adjustable) setpoint.

Most drop-ins are not designed to handle fast C-rate charging, so the ability to throttle current is even more critical than with a proper system based on prismatics.

Nothing about drop-ins' internal electronics has anything to do with Firefly batts.

The biggest problem with them is lack of external communications, no integration with the rest of the system.

[BigBeakie]

So would you lump the batteries from Valence as "drop ins"? And would you include the control offered by Victron battery chargers in conjunction with Valence LMnFePO4 batts as not adequate for LFP?


Sent from my iPad using Cruisers Sailing Forum

[Hoopla]

Originally Posted by BigBeakie

So would you lump the batteries from Valence as "drop ins"? And would you include the control offered by Victron battery chargers in conjunction with Valence LMnFePO4 batts as not adequate for LFP?


Sent from my iPad using Cruisers Sailing Forum

Valence has a external BMS and appear to offer a partly "Intergted System" designed to operate with third party charge sources which is a step up from "Drop In" that communicates with nothing. However the problem with Valence is two fold and common to a lot of suppliers of LFP batteries or equipment.

It firstly assumes those charge sources are all CAN capable. While this is possibly OK for AC Chargers it largely precludes all other charge sources common on sailboats relying on analogue or some form of potential free control to turn them off.

Secondly it does not appear to have the means to control either third party or proprietary external load and charge contactors.

What is forgotten is house power on sailboats has peculiar requirements not found in off-grid, industrial, UPS, applications etc and being a relatively small market is open to having wrongly engineered products offered up as being suitable for marine use.

Properly engineered LFP marine options fall into three types

1. Integrated Expert/DIY incorporating sourced components incl external BMS that interactes with 3rd party external charge sources and loads. There are numerous small volume local/regional type suppliers in this space that operate mostly on a supply and install basis.

2. Integrated Systems with proprietary Battery and external BMS that works with 3rd party ancillaries including alternators ie. Lithionics (and previously Genasun).

3. Proprietary Integrated Systems are the complete package that work with their proprietary Battery packs and monitoring and charge ancillaries. ie Masterbolt, Victron

"Drop Ins" integrate or communicate with nothing and sold as that not being necessary using charge and discharge specs that will at best murder the battery or worse are a safety issue.

[Hoopla]

Originally Posted by john61ct

The problem with alternators is not large vs small, but proper VR handling of temps rising due to the bank pulling high current rates.

An external VR like Balmar MC-612 does proper staged charging, and when the alt gets hot will reduce current output but keep voltage at the (adjustable) setpoint.

Most drop-ins are not designed to handle fast C-rate charging, so the ability to throttle current is even more critical than with a proper system based on prismatics.

Nothing about drop-ins' internal electronics has anything to do with Firefly batts.

The biggest problem with them is lack of external communications, no integration with the rest of the system.

Actually it is slightly misleading suggesting external regulation automaticaly makes small and large case alternators alike suitable for for dealing with alternator temperature isses and the acceptance rate of LFP. External regulation does so by manually limiting output to an appropriate level below rated output and or with alternator temperature sensing.

However as there is no such thing as a free lunch this simply means the high acceptance feature of LFP is not being taken advantage of by having alternator output wound back. The other aspect external regulation can't deal with is time spent at the selected output or maximum temperature. Ordinarily a LA battery performs this function by it's acceptable rate falling off. A LFP battery won't do this.

The realty is for all alternators and particularly so with small case varients with LFP is either accept a lesser output and over an extended period this might not be enough to prevent heat impacts on components or alternatively remove heat with an external rectifier to both protect and raise output.

[Hoopla]

Originally Posted by OceanPlanet

New ABYC standards will address Li very well, including drop in. However the process of creating those standards has been a long one....it's a lot of work. Some very good people involved, especially Nigel Calder. Don't know what ABYC would do without him...

The world not just the US is the greatful beneficiary of the ABYC and those who volunteer their expertise. Wonderful organisation.

[Mick C]

Hi
I’m not specifically sure what is meant by
“drop in” batteries. Is it a straight swap of Lead Acid/gel/amg with lithium batteries or do we mean dropping in a self contained Lithium battery mini system in a premanufactured casing?
If it’s a swap of LA/Gel/AGM batteries with a Lithium then it’s the wrong thing to do. It’s a different system entirely required. Even with the premanufacturd “case” batteries the system needs to change too!!! So if you are considering going to Lithium (let’s call the ones under consideration LiFePo) then you need to review every charging source and feed/direct distribution cable.

Take note of the discussion above re the “smart limiter” moderating the alternator’s workload via a temp sensor in the Hall. A good one of these is essential and needs to be configured to the LiFePo. The brand mentioned or the Sterling work well. We use two, one on each engine.

Battery chargers have to be programmable, the “Lithium setting can be conflicting with other solar/wind controllers. Choose a set of setting and then align all your sources!

Mick

[Hoopla]

Originally Posted by jkleins

Can you expand upon the problems with the drop in batteries a bit? The comments that came after yours assumed too small an alternator or lack of adequate charging source but is there more?
I was assuming that anyone looking at lithium would already have a large alternator that could handle large loads and a regulator that was adjustable to handle whatever the recommended settings of the battery would be. The integrated BMS seems like a good idea in that situation making them similar to the Firefly batteries.
Is there something particular about the integrated BMS or just the particular Smart Battery that makes it undesirable?

Jim

Jim my two posts above I think deal with both your Alternator and Integrated System (external BMS) that communicates externally versus Drop-In (internal BMS) that is not integrated and can't communicate externally.

I'm assuming your Firefly comment is directed at it (and some other carbon LA types) having discharge/charge and capacity shrinkage performance more closely aligned to LFP not LA, yet being a "drop-in" alternative to LA. That aspect is correct.

However "Drop-In LFP" bears no resemblance at all to Firefly and similiar LA carbon types, other than less than truthfull LFP vendors adopting the "Drop- In" word in their marketing material by selling a LFP energy storage solution that has no means to be properly integrated for communication on a cell by cell basis during use just like LA, but which LA or its derivatives don't need other than pack voltage and temperature as a option and are relatively cheap.

OceanPlanets link up thread to a Better Business Bureau ranking of 1 1/2 stars or an F against the Smart Battery crowd said it all about the outcomes that most sailboat users can expect by installing Drop-in LFP, no matter the vendor.

[Hoopla]

Originally Posted by Mick C

Hi
I’m not specifically sure what is meant by
“drop in” batteries. Is it a straight swap of Lead Acid/gel/amg with lithium batteries or do we mean dropping in a self contained Lithium battery mini system in a premanufactured casing? ....

Mick

Mick both. "Drop In LFP" refers to both a group of LFP cells linked to provide a pack voltage or the same but packaged up with a "built in BMS" that can't communicate externally other than voltage via charge and or load sources using the same reticulation link.

The integration or installation of properly configured charge sources to match LFP battery chemistry is required regardless of being Drop-In or Integrated with an external BMS that communicates externally.

However "Drop-In" vendors market their product as not requiring either external communication or any changes to charge or load reticulation or sources needed to both protect the battery and those sources. They do this by publishing charge and discharge specifications (and configuring internal BMS accordingly) outside what LFP battery chemistry can tolerate and therefore will either murder the battery and indirectly charge sources (alternator diodes in particular) or worse potentialy become unsafe.

[Hoopla]

Originally Posted by Mick C

Hi

...If it’s a swap of LA/Gel/AGM batteries with a Lithium then it’s the wrong thing to do. It’s a different system entirely required. Even with the premanufacturd “case” batteries the system needs to change too!!! So if you are considering going to Lithium (let’s call the ones under consideration LiFePo) then you need to review every charging source and feed/direct distribution cable.

Take note of the discussion above re the “smart limiter” moderating the alternator’s workload via a temp sensor in the Hall. A good one of these is essential and needs to be configured to the LiFePo. The brand mentioned or the Sterling work well. We use two, one on each engine.

Battery chargers have to be programmable, the “Lithium setting can be conflicting with other solar/wind controllers. Choose a set of setting and then align all your sources!

Mick

Mick I have replied to your post in two parts as the issues with "Drop-In LFP" have two distinct parts, the system itself and then integration with onboard gear.

I addressed both parts but to answer the balance of your Post. You are are on the money about having to configure charge sources to match battery chemistry. That has never really been the case until recent times.

Unfortunately for over 40 years battery vendors initially paid scant regard to that when releasing to the market new battery chemistry to replace Flooded Lead Acid (FLA) with Sealed Lead Acid (SLA) variants. The net result is some of those new chemistries got a horrible name because they marketed them as being a "drop-in" replacement to FLA. By the way unless constrained by maintenance or by racing rules to having SLA, FLA is still hard to beat for a vast majority of sailboat uses.

For example the GEL name (probably one of the nicest of SLA's) got murdered simply because they will die with the wrong set point and float voltages, bearing in mind in marine world external alternator regulators and programmable AC Chargers were not on most boats back then.

Another good example is AGM and its many varients are not so much voltage sensitive but have a Charge Acceptance Rate way above FLA. The net result is those in the business of replacing small case auto style alternators have sent their kids to college. The intriguing thing is diesel auxiliary engine manufactures have only in recent times woken up to this by offering up larger and more robust small case alternators and dual alternator options.

So "Drop-In LFP" is really a back to future thing. We are seeing the same thing happen. However the preferred LFP system impacts on a wider and more costly thing being not just charge source, but also power reticulation. Existing LA reticulation and it's ancillaries being fusing and charge/load buss design etc won't cut the mustard with LFP.

Hopefully threads like this and the forthcoming ABYC Standards and which OceanPlanet refers to above (which the World takes notice of) will save us a couple decades of navel gazing to agree on what works and doesn't work in sailboat land having regard to LFP. While many may be critical for how long these ABYC LFP standards have been in the making it is a extremely difficult exercise. For example putting aside protecting asset value LFP cells have extremely low series resistance and so produce an extremely high short circuit current compared to LA. In simple terms that equals a high potential for circuitry fire for an installation that doesn't accomodate LFP.

My guess is those ABYC standards won't differ too greatly to advice put forward in this thread having regard to use and operation involving LFP and whilst they may accommodate "Drop-Ins" will come with many caveats the "Drop-In" industry won't like.

[jkleins]

Originally Posted by john61ct

The problem with alternators is not large vs small, but proper VR handling of temps rising due to the bank pulling high current rates.

An external VR like Balmar MC-612 does proper staged charging, and when the alt gets hot will reduce current output but keep voltage at the (adjustable) setpoint.

Most drop-ins are not designed to handle fast C-rate charging, so the ability to throttle current is even more critical than with a proper system based on prismatics.

Nothing about drop-ins' internal electronics has anything to do with Firefly batts.

The biggest problem with them is lack of external communications, no integration with the rest of the system.

I do thank many of you for trying to answer my question but I am hearing communication, integration without really understanding what the communication is trying to achieve.
What does the battery need to tell the alternator other then what voltage to provide it? If the alternator can handle the load and is properly regulated to protect itself while keeping the voltage at the set point what other communication is needed or provided by these integrated systems that a smart regulator won’t or can’t provide?
The BMS function that is about protecting the battery from getting too high or too low a voltage at the cell level seems to be handled by the drop in BMS. What are the other functions that the non drop in BMS’s do that make them superior?

Jim

[john61ct]

Originally Posted by Hoopla

Actually it is slightly misleading suggesting external regulation automaticaly makes small and large case alternators alike suitable for for dealing with alternator temperature isses and the acceptance rate of LFP.

I made no such claim.

Obviously protecting the alt from its inadequate stock VR not designed for a high CAR bank is a basic necessary step, even if not in itself providing the highest possible current rate.

A robust DCDC charger would also work.

Many who want to take advantage of alt charging are not able or willing to change to a specialized high-output alt. The alt may not even be a significant energy source overall, so not worth spending a lot on.

The issue of halting charge when full is a separate issue, again, multiple ways to deal with that.

Yes, moving the diodes off the alt can allow for increased current rates.

[john61ct]

Originally Posted by Mick C

Hi
I’m not specifically sure what is meant by
“drop in” batteries.

An enclosed lithium 12V bank, internal BMS electronics (LVD / OVD, balancing, maybe also current limiting and / or temperature protection) and individual cells not accessible from the outside.

Marketed as a direct replacement for lead batts without having to change any of the surrounding infrastructure.

Battle Born being apparently a quality example in the NA market.

[john61ct]

Originally Posted by jkleins

I do thank many of you for trying to answer my question but I am hearing communication, integration without really understanding what the communication is trying to achieve.
What does the battery need to tell the alternator other then what voltage to provide it? If the alternator can handle the load and is properly regulated to protect itself while keeping the voltage at the set point what other communication is needed or provided by these integrated systems that a smart regulator won’t or can’t provide?
The BMS function that is about protecting the battery from getting too high or too low a voltage at the cell level seems to be handled by the drop in BMS. What are the other functions that the non drop in BMS’s do that make them superior?

The internal BMS often drastically limits charge / discharge rates to a tiny fraction of LFP's capabilities.

The maker and quality of the internal cells is unknown, may not have the lifespan of CALB, Sinopoly, GBS or Winston.

It may even mask the fact that the batt is LiPo or NMC rather than LFP.

Terminating charging when full, or when temps get too low should be able to signal other gear, or controlling generic relays.

As opposed to simply taking the batt offline without warning, which can fry diodes.

Allowing the "Full" or "Too Low" setpoints to be adjusted by the user to extend lifespan.

Allowing the user to see the state of cell balance, verify that BMS function is working.

Allowing a cell to be swapped out if one proves faulty.