Drop in lithium batteries

[Delfin]

Originally Posted by john61ct

Yes and with thoughtful planning they can be made to "work" in the normal sense.

But following mfg specs will you get enough longevity to make a decent ROI on the high acquisition cost compared to quality lead?

No.

Which is what terser commentators mean when they say "impossible" or "no such thing".

The basis for your statement regarding mfg recommendations shortening the life of Li batteries is based on your belief that said mfg think it serves their interests to have unhappy customers, or don't care. Since this doesn't work in any other product area, I doubt Li mfg are that daft.

If these batteries are charged as recommended, then disconnected from charging sources they will provide as many cycles as advertised, so yes they do provide ROI over lead if you use them enough to make them pay.

[a64pilot]

Originally Posted by Delfin

The basis for your statement regarding mfg recommendations shortening the life of Li batteries is based on your belief that said mfg think it serves their interests to have unhappy customers, or don't care. Since this doesn't work in any other product area, I doubt Li mfg are that daft.

If these batteries are charged as recommended, then disconnected from charging sources they will provide as many cycles as advertised, so yes they do provide ROI over lead if you use them enough to make them pay.

Yes, and as far as "fixing" them, no there will be no more fixing one of them than say a Balmar Alternator controller or any other solid state component on the boat, Radar, Radios etc.

Drop in is for the guy who doesn't want to know how it works or why. Just wants it to work.
Very few people understand how a car works, yet Billions drive them

[svlamorocha]

Originally Posted by john61ct

Well there are ones that do, likely more than just victron's.

"Hybrid drop-in?"

We have a language problem. The very definition of "drop in" lithium battery solution is a box that you buy and has only two 12V terminals to connect to the rest of the boat using all the kit that was there before and just replacing a lead box with a lithium box just by disconnecting the two fat DC wires from the old lead box to the new LFP box

The Victron batteries have other terminals in addition to the two 12V terminals and fall in a different category. Mainesail calls it "Marine-specific LFP systems"; make your own name if you want.

[svlamorocha]

Originally Posted by thinwater

Neither do other batteries (and yes, I understand they are different in critical ways). Since you statement is at the very heart of the thread, why not elaborate? Without details, your statement could more efficiently be shortened to "no."

Lead batteries can be used without a BMS, etc because the chemistry's intrinsic inefficiency means you cannot screw up big time just by overcharging, etc. Lead batteries will break water into hydrogen and oxygen; they will generate heat, etc to cope with the overcharging without "property damage"

[a64pilot]

Originally Posted by svlamorocha

We have a language problem. The very definition of "drop in" lithium battery solution is a box that you buy and has only two 12V terminals to connect to the rest of the boat using all the kit that was there before and just replacing a lead box with a lithium box just by disconnecting the two fat DC wires from the old lead box to the new LFP box.

That would be ideal, however I think the alternator may have to be treated differently, or there could be a small lead acid battery or capacitor or something that remains connected when the LFP bank disconnects from charging sources to keep it from just going to an open circuit.

My only point is that if average Joe’s can cob together pieces parts and make an LFP a DIY thing, we’ll surely a major manufacturer can.
I can only assume there either isn’t a market big enough to make it pay for itself.
But maybe with what seems to be a push for off grid living, that will change.
I don’t think drop in LFP’s would be any harder to solve than save building a Watermaker, and there are many manufacturers of those.
So, who knows?

On edit, a “drop in”could have an electronics module if you will, a battery sized box the you make your connections to, and it connect to the LFP bank.

[john61ct]

Originally Posted by Delfin

The basis for your statement regarding mfg recommendations shortening the life of Li batteries is based on your belief that said mfg think it serves their interests to have unhappy customers, or don't care.

No it is based on fact, regardless of what the reasons might be.

> Since this doesn't work in any other product area, I doubt Li mfg are that daft.

Really? What, you think the interests of the consumer is all that drives vendor decisions in a free market?

It would be child's play for manufacturers in almost all categories to create versions of their consumer products designed to last 50 even a hundred years. Would not even cost much more. Yet somehow we don't see that happen too often. Maybe there's a logical reason for that.

> If these batteries are charged as recommended, then disconnected from charging sources they will provide as many cycles as advertised

Yes but that is a small fraction of their lifespan if cycled a little more gently avoiding the voltage shoulders.

But that is much less certain if we don't know who made the cells inside.

[Delfin]

Originally Posted by john61ct

No it is based on fact, regardless of what the reasons might be.

> Since this doesn't work in any other product area, I doubt Li mfg are that daft.

Really? What, you think the interests of the consumer is all that drives vendor decisions in a free market?

It would be child's play for manufacturers in almost all categories to create versions of their consumer products designed to last 50 even a hundred years. Would not even cost much more. Yet somehow we don't see that happen too often. Maybe there's a logical reason for that.

> If these batteries are charged as recommended, then disconnected from charging sources they will provide as many cycles as advertised

Yes but that is a small fraction of their lifespan if cycled a little more gently avoiding the voltage shoulders.

But that is much less certain if we don't know who made the cells inside.

I think I have asked (as have others) for the proof of declarative statements like the above. Probably missed it, but could you provide the physical/chemical reason why, when Lithionics says to charge their batteries to 14.4 vdc (and they say this to the U.S. government who buys their products), then have the minimal amount of time possible for absorption before going to float, that what they are really doing is pulling the wool over the eyes of their customers and intentionally sabotaging their product, believing apparently that when the batteries fail, their customers will buy more of that product? You said it was a fact that this is the case, so I am merely asking for the factual basis of that statement, no offense intended.

Then, if you could provide the test results that show that the lifespan of LiFePO4 batteries is significantly extended when you avoid ever touching the voltage shoulders rather than recharging until the CAR drops to around 2.5% then disconnect charging (which on my system happens around 28.2 volts or so), your declarative statement on this subject could be verified. I'm aware of horror stories of people pumping high voltages to Li batts for hours past the point where they are full, or floating them at something other than open circuit voltages for weeks on end, but I don't think these are practices recommended by manufacturers.

Finally, can you point me to a product produced in a global market where competitors don't bother trying to gain market share by improving the longevity/cost/quality of their products but instead globally collaborate to enforce planned obsolescence and tell their customers to maintain their products in such a way as to reduce their cost effectiveness? Just one will do.

[svlamorocha]

Originally Posted by a64pilot

That would be ideal, however I think the alternator may have to be treated differently, or there could be a small lead acid battery or capacitor or something that remains connected when the LFP bank disconnects from charging sources to keep it from just going to an open circuit.

My only point is that if average Joe’s can cob together pieces parts and make an LFP a DIY thing, we’ll surely a major manufacturer can.
I can only assume there either isn’t a market big enough to make it pay for itself.
But maybe with what seems to be a push for off grid living, that will change.
I don’t think drop in LFP’s would be any harder to solve than save building a Watermaker, and there are many manufacturers of those.
So, who knows?

On edit, a “drop in”could have an electronics module if you will, a battery sized box the you make your connections to, and it connect to the LFP bank.

Victron makes a great LFP solution but it is not "drop-in". Same about Lithionics. Both interact with the rest of the boat's electrical system through more wires than the two fat DC wires.

[john61ct]

Here's my "boilerplate" LFP summary

Any and all feedback is welcome, especially if more "canonical" information from the links cited conflict with this summary.

______
Systems: OceanPlanet (Lithionics), Victron, MasterVolt, Redarc (Oz specific?)

Bare cells: ​Winston/Voltronix, CALB, GBS, A123 & Sinopoly

Best to size your cells for two parallel strings for redundancy, unless you have a separate reserve/backup bank. Don't go past three, or you may see balancing issues that affect long-term longevity, maybe four in a pinch.

Note nearly **every** vendor, also those of ancillary hardware touted as "LFP ready", gives charging voltages **way too high** for longevity.

EV usage is very different from much gentler House bank cycling. Most EV people talking "lithium-ion" mean other chemistries not as safe as LFP, much shorter lifetimes, and with completely different setpoints and behaviors.

My charge settings for LFP: 3.45Vpc, which = 13.8V max for 4S "12V".

The point is to look at the SoC vs Voltage chart, and avoid the "shoulders" at both ends, stay in the smooth parts of the curve.

Either "just stop" charging when voltage is hit, or if you want another couple % SoC capacity, stop when trailing amps **at your spec'd voltage** hits endAmps of .02C, or 2A per 100AH.*

Note even at the "low" max charge voltage, letting the charge source continue to "push" even low currents long past the endAmps point is **over-charging, and will** greatly reduce lifecycles.

So if you can't then "just stop", set Float well below resting Full voltage, at say 13.1V, but that is a compromise, and *may* shorten life cycles.

With LFP, you don't need to fill up all the way at all, as far as the cells are concerned. In fact, it is bad for them to sit there more than a few minutes. Therefore only "fill up" if consumer loads are present, ready to start discharging, ideally right away.

Many sources claim there is a "memory effect" from keeping charge voltage and ending point exactly the same every time lower than manufacturer specs, that can apparently over time lead to apparent lower capacity. The recommended fix is to "go higher, into the shoulder" every so often, similar to "conditioning" a FLA bank monthly. To prevent the issue, vary your setpoints a bit, sometimes go a point or two higher or lower, vary Absorb time a bit etc. There is no consensus just how serious the problem is.

Store the bank as cool as possible and at 10-20% SoC, or maybe higher to compensate for self-discharge, if not getting topped up regularly (I would at least monthly).*

Letting the batts go "dead flat" = instant **permanent unrecoverable** damage.

Same with charging in below 32°F / 0°C freezing temps.

Persistent high temps also drastically shortens life.

Charging at 1C or even higher is no problem, as long as your wiring is that robust, vendors may spec lower out of legal caution.

Again, going above 14V won't add much AH capacity, but will shorten life cycles dramatically.

And of course, we're talking about gentle "partial C" House bank discharge rates, size appropriately and be careful feeding heavy loads like a winch or windlass.

Following these tips, letting the BMS do active balancing is unnecessary and potentially harmful, just look for LVD / OVD and temp protection. Multiple layers of protection are advised if it is a very expensive bank, so you don't rely on any one device to keep working.

Check cell-level voltage balance say monthly to start, then quarterly, finally every six months if there are no imbalance issues, but only if that seems safe to you.

This thread is long but informative
http://www.cruisersforum.com/forums/...nks-65069.html

, make sure to give both Maine Sail and Ocean Planet your close attention.

Also MS' summary notes here
https://marinehowto.com/lifepo4-batteries-on-boats/

**Everything** at that site is worth reading, very valuable. He also has great articles in Practical Sailor. His new site under development transitioning the pbase content is here

https://marinehowto.com/support, feel free to make a donation to help with those expenses.

[CapnBazza]

Originally Posted by admiralslater

I have seen a lot of action in the lithium drop in replacement batteries market Brand such as Battle Born and the one from coastal climate offer batteries with built in bms. That are starting to look relatively affordable (I did say relatively).
The bid advantage is the straight swap ,assuming the charging system is appropriate.
Has anyone had experience with these

Yes, but I have only had them for three years. So far, so good.

[Nicholson58]

I learned a lot from this site

https://marinehowto.com/lifepo4-batteries-on-boats/

He is very negative on drop in replacements with good reasons explained. Note - anyone who tells you to float a Li battery has much to learn.

[mikedefieslife]

Consider a “drop in” pack like Relion.

They have explicitly stated the following;

“up to 14.6V, in fact, LiFePO4 can handle a higher voltage, however as Craig pointed out, you can extend cycle life if you reduce the charge, simply because this will reduce the depth of discharge.

Please note, that our recommended charge voltage is 14.2V – 14.6V, however balancing will not take place unless it is charged to 14.4.”

Now based on what we know in this thread about the technology. How long would we expect these so called drop ins to last in a typical marine cruising environment?

I couldn’t see what sort of guarantee they offer. In contrast Rolls that 7 year guarantee plastered all over their website.

[gspeak]

iTech World in Perth, Western Australia have just released 120AH Drop In lithium Batteries.

They don't appear to display a lot of specifications, but state that these are complete drop ins.

I am on their mail list as I bought one of their 900A Portable Jump Starter Backup Power Packs which is a great, well built product.

The price online for the Lithium Battery is shown as AUD$1,199 with 2 year warranty, but they are offering them for AUD$849 to Newsletter customers by using a Discount Code.

I have no idea of this product as I'm no Lithium Nerd, just offering it as it appears to be purporting to be just what this Topic is all about.

I'd be happy if anybody can find out more & even recommend it.

Check out the Download Brochures at the bottom of page for more info

https://itechworld.com.au/collection...ithium-battery

Dave

[Delfin]

Thanks John. Based on two years experience so far with my own LiFePO4 bank much of what you observe I agree with, but some not:

Originally Posted by john61ct

Note nearly **every** vendor, also those of ancillary hardware touted as "LFP ready", gives charging voltages **way too high** for longevity.

You've provided no evidence of this other than saying it is so. I think you are confusing Constant Current voltage settings with Constant Voltage settings. As CMS notes, when pressed for clarity, manufacturers make it clear that high CV absorption charging is harmful. However, setting bulk charging, CC rates, to just north of 28 volts, then disconnecting the charge source when the acceptance rate falls is harmless and ensures the shortest time to re-charge.

Originally Posted by john61ct

My charge settings for LFP: 3.45Vpc, which = 13.8V max for 4S "12V".

I tried those settings and it increases the time to re-charge significantly. If what you mean is stop charging when cell voltage reaches 3.45V, AND the acceptance rate has dropped to a small percentage of total capacity, then that's just fine, but if you simply charge the bank until it reaches 3.45v, it may be anywhere from 40% to 80% filled. Does that make any sense?

Originally Posted by john61ct

The point is to look at the SoC vs Voltage chart, and avoid the "shoulders" at both ends, stay in the smooth parts of the curve.

I think if you look at a SoC vs Voltage chart, you will see that higher voltages are still in the "flat part" of the curve. Some good information from Lithionics is located here that you might find helpful: http://lithionicsbattery.com/wp-cont...de-2-19-14.pdf

Originally Posted by john61ct

Either "just stop" charging when voltage is hit, or if you want another couple % SoC capacity, stop when trailing amps **at your spec'd voltage** hits endAmps of .02C, or 2A per 100AH.*

This implies that the capacity of an Li bank increases as the voltage you are charging it to increases. That would be the case with lead acid batteries, but not Li batteries, which are so efficient their capacity (not their SoC) doesn't increase when you increase the voltage. All you do by pumping more current at an Li bank after it is full is generate heat.

Originally Posted by john61ct

With LFP, you don't need to fill up all the way at all, as far as the cells are concerned. In fact, it is bad for them to sit there more than a few minutes. Therefore only "fill up" if consumer loads are present, ready to start discharging, ideally right away.

Never heard that one before. Could you provide a source of information that supports the idea that it is bad for an Li bank to sit fully charged for more than a few minutes?

Originally Posted by john61ct

To prevent the issue, vary your setpoints a bit, sometimes go a point or two higher or lower, vary Absorb time a bit etc.

If there is one thing everyone seems to agree on, and that is that any absorption phase is pointless with Li batts, and is generally where any to them damage is generally done.

Originally Posted by john61ct

Store the bank as cool as possible and at 10-20% SoC, or maybe higher to compensate for self-discharge, if not getting topped up regularly (I would at least monthly).*

Again, this is a new one. 40 - 50% SoC for storage seems generally advised, but could you verify where your 10% - 20% target comes from? And they don't self-discharge, at least mine don't over months so topping up seems questionable advice.

Originally Posted by john61ct

Again, going above 14V won't add much AH capacity, but will shorten life cycles dramatically.

Already discussed but I'd love to see your data supporting this assertion. However, if you want your Li bank to last a really long time, don't discharge it to a SoC of much below 40% and certainly not to the 10% you mention as a storage SoC. Lithionics states that based on their testing, you should get 2400 cycles with an 80% DoD, but 35,000 at 10%. If you discharge to 50% capacity, the projected cycles are close to 6,000. And these are at a 1C discharge rate, which is a great deal more aggressive than one would experience in real life.

[Delfin]

Originally Posted by a64pilot

That would be ideal, however I think the alternator may have to be treated differently, or there could be a small lead acid battery or capacitor or something that remains connected when the LFP bank disconnects from charging sources to keep it from just going to an open circuit.

Many boats have two banks, one house and one starting. When I installed my Li bank, it replaced the house AGMs and I kept the LA starter bank as a destination for charge current when the Li bank is disconnected from charging after it is as full as I need it to be. This seems to work well for us. Lithionics supplies an alternator disconnect via field effect fiddling when their BMS takes the Li bank off line to avoid alternator damage. I haven't bothered to install it yet, since I disconnect charge current long before a high voltage cut off could be triggered by the BMS, but I think I will as a safety precaution.