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Lithium drop-ins round 3

1078 Views 23 Replies 8 Participants Last post by JohnBPrice, 14 h ago

Don L

Discussion Starter · 3 mo ago (Edited)

I have now had my "cheap" LFP 100ah batteries 2.5 months. This morning I am at the lowest I ever have allowed my house battery bank to get, way less than I allowed my lead acid, and they are working fine.

I paid $309.99/ea for these batteries including shipping off Amazon. At the time there had to have been at least 6 other manufacturers/supplies of LFP drip-ins with the same basic spec and price.There were enough choices that I got confused and acturally think I ordered different batteries than I planned.

So now days, just who is it that somehow believes they need to get LFP drop-ins with the same specs that cost $800+/each (because google just decided I need to learn about Battleborn that are $874 on Amazon for the same spec)? Do some acturally believe that some other "builder", cause they don"t really make anything just package it together, has $500 extra magic in their boxes? Both the $300 and $800+ battery people are basically just using marketing of unknowns to get you to buy their batteries.

If there are 6+ suppliers of the same spec battery for $300 how can you believe the $800+ guy is doing something special to increase the price so much?

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SchockT

· #2 · 3 mo ago

It's encouraging to know that lithium batteries can be inexpensive, but 2.5 months of use is not exactly a long term test. The victory lap might be a bit premature! Get back to us in a year or more!

I would be curious to see some comparison tests between the cheapo batteries and their more expensive name brand equivalents.

Sent from my SM-G981W using Tapatalk

Reactions: 1

Don L

Discussion Starter · #3 · 3 mo ago

SchockT said:
I would be curious to see some comparison tests between the cheapo batteries and their more expensive name brand equivalents.

Sent from my SM-G981W using Tapatalk

Well just look them up. I am not trying to say that the $800+ don't have something "better" on paper. Many of the $300 ones don"t have low temp protection, which matter nothing to most people not planning to charge their batteries in freezing conditions. Many $800+ also accept more charge current than the $300, but that matters nothing since the vast majority of users they can accept all that can be supplied by the boat systems (my 400ah bank can accept 400a and I can max supply about 170a if I run every source I have at same time).

I noticed that on Maine Sails recommended products on Amazon there is now the $300/100ah Li-Time (used to be Amphere-Hours) brand battery

You can find the tear downs for your comparison on line with no problem.

And yes I have only had 2.5 months and that is nothing. But no one has had those $800+ ones long enough to get close to the cycle numbers they claim so are they just making that up??? If I get only 3-5 years full time use out of a $300 battery that IMO is a massive victory once you figure in the other advantages over the same lift cycle of lead acid.

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Don L

Discussion Starter · #4 · 4 d ago

SchockT said:
It's encouraging to know that lithium batteries can be inexpensive, but 2.5 months of use is not exactly a long term test. The victory lap might be a bit premature! Get back to us in a year or more!

I would be curious to see some comparison tests between the cheapo batteries and their more expensive name brand equivalents.

Sent from my SM-G981W using Tapatalk

Not a year, but 6 months now with no problems.

colemj

· #5 · 4 d ago

It is interesting that so many people will recommend buying cheap Sams Club Duracell 6V lead batteries over Trojan T105's because they are almost the same and can buy 3 sets for the price of T105's, yet question the exact same reasoning with LFP.

Not sure what comparisons would be useful. The expected lifetime of even the cheapest, shortest lived LFP battery is so long that by the time any comparison could be done, it wouldn't matter.

One takeaway I think DonL is trying to make is that unless one is buying Sams Club Duracell's, LFP batteries are now as cheap as, or cheaper than, any equivalent lead battery.

Mark

Don L

Discussion Starter · #6 · 4 d ago

I have had the Duracell 6V batteries and the Trojan T105s. They last the same amount of time. If you are a weekend boat user who goes back to the marina and shorepower I think these are still great bang for the buck

But if you are a frequent off grid boater the big battle is always going to be partial state of charge and it seems* LFP is the only game to for that. I could have gotten my current house bank with the T105 types and saved a few $100, but .................

* my last set of batteries were FireFly carbon foam. They weren't suppose to suffer from PSOC and I paid $2000 a 481ah bank. They lasted 2.5 years!!!!!! So to me chancing my cheap LFP at $1300 for 400ah seemed to be worth the risk. But if they only last 5 years that is just fine with me.

4arch

· #7 · 4 d ago

Don L said:
If you are a weekend boat user who goes back to the marina and shorepower I think these are still great bang for the buck

I'm not even sure that's true anymore. I just picked up 2x LiTime 200Ah for $1070 out the door. Duracels would have been $500 for 4 (I only paid $270 for my last set five years ago - inflation hit FLA batteries pretty hard!). So I paid double but will get 1.5x as many usable Ah and hopefully at least double the lifespan. Seemed like the better value play. But I will have to be careful not to overcharge them on shore power.

Reactions: 1

PGandW

· #8 · 4 d ago

Besides cost, the biggest drawback to LiFePO batteries is changing your systems AND your thinking. For long life, FLA batteries love to kept at full charge as much as possible, and seldom taken below 50%. The bigger the battery bank the better.

For long life, LiFePO batteries should be kept well below 100%, and cycled between 20% and 80%. The only reason to go to 100% is for the occasional cell balancing. Our human inclination is to have the battery full when we cast off because we never know how much battery we are going to need (just like leaving the dock with less than full gas/diesel or water). Which drives up the size and cost of our LiFePO bank if we are going to maintain at less than 100%.

Fred W

colemj

· #9 · 4 d ago

Not sure how much experience you have with LFP batteries, but none of the above is correct information.

It is true that one should not STORE LFP at 100% SOC for long periods of time, but there is absolutely no harm in taking them TO 100% SOC as often as you like - daily for sure.

There is also no need to cycle between 20-80%. Probably don't want to go too far below 20% because running them dead flat isn't the best thing to do, but charging them back to 100% is no problem at all. It is fine to leave the dock with them at 100%.

While charging them to 100% won't decrease their lifespan, even if it did it could cut their life by a factor of 5 before they fell to the lifespan of lead batteries.

I don't understand your thinking about driving up the size of the LFP bank. They already get 40% more practical capacity than lead just by being able to regularly use them below 50% SOC.

Most people will not need to change anything in their electrical system to use LFP. Maybe if they have a very ancient mains charger, or an alternator that is too fragile for LFP. In these cases, then they would need a modern charger and move the alternator to the start battery instead of the house. Possibly an upgrade in fuses, and maybe some appropriate wiring.

LFP doesn't really cost any more than equivalent lead, other than the least expensive ones like the Duracells mentioned earlier. This has been hashed out many times, and DonL has shown it to be true here by using his wallet as proof.

Mark

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Don L

Discussion Starter · #10 · 4 d ago

colemj said:
This has been hashed out many times, and DonL has shown it to be true here by using his wallet as proof.

Mark

I am open to donations to offset the experimental costs.

Reactions: 1

PGandW

· #11 · 4 d ago

colemj said:
It is true that one should not STORE LFP at 100% SOC for long periods of time, but there is absolutely no harm in taking them TO 100% SOC as often as you like - daily for sure.

There is also no need to cycle between 20-80%. Probably don't want to go too far below 20% because running them dead flat isn't the best thing to do, but charging them back to 100% is no problem at all. It is fine to leave the dock with them at 100%.

While charging them to 100% won't decrease their lifespan, even if it did it could cut their life by a factor of 5 before they fell to the lifespan of lead batteries.

I don't understand your thinking about driving up the size of the LFP bank. They already get 40% more practical capacity than lead just by being able to regularly use them below 50% SOC.

Most people will not need to change anything in their electrical system to use LFP. Maybe if they have a very ancient mains charger, or an alternator that is too fragile for LFP. In these cases, then they would need a modern charger and move the alternator to the start battery instead of the house. Possibly an upgrade in fuses, and maybe some appropriate wiring.

LFP doesn't really cost any more than equivalent lead, other than the least expensive ones like the Duracells mentioned earlier. This has been hashed out many times, and DonL has shown it to be true here by using his wallet as proof.
Mark

Mark
Thank you for pointing out the very different use cases. My use case is a "cruising" trailer sailor. There is no separate house and starting battery bank. We go out, anchor out for a few nights (less than a week), then spend a night in a marina or go home. To do it again in who knows how many weeks while the boat sits. Battery powers lights, a few instruments (I only have a compass light now), VHF radio, depth sounder, recharge cell phone, and handheld VHF. Occasional use of a stereo, and a 12V fan in the cabin. No solar, outboard engine, but electric power at the dock.

In other words, storage, then immediate use without recharge until end of trip or stay in marina.

My preferred LA solution for this use case is a pair of GC-2 6V 210AH LA batteries. My last set cost $95 each at Costco, but we'll assume they are now $125 each. Switching to a 100AH "drop in" LiFePO - which I think is an excellent idea for marine use - costs $400-$600 for the battery with a good BMS. I also have to have a Li-compatible charger to use dockside - multi-stage chargers before 2016 generally don't have the correct charging algorithms for Li. The dockside charger also must have an auto-shutoff in Li mode, leaving Li batteries on "float" for weeks is exactly the wrong way to treat them. Then the "store at 70%" rears its ugly head. If I'm not using the boat for 2-4 weeks, then according to many Li battery manufacturers, I should go down to 70%. If I store at 70%, I have 50AH available for my next trip (70AH if I go down to 0). When I arrive at the dock for my next trip, I don't want to spend an hour recharging my battery to 100%.

I'm just pointing out that for my use case, the 100AH "drop-in" is not really equivalent to the 210AH LA because of the charge and storage paradigms. To get there, I really need 200AH "drop-in" Li, which takes my total cost up to at least $900.

Fred W

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colemj

· #12 · 4 d ago

PGandW said:
I'm just pointing out that for my use case

I don't disagree with your use case, but you didn't present that case - you presented general information that was incorrect.

Mark

Arcb

· #13 · 3 d ago (Edited)

When I first got interested in Lithium batteries I did some of my own research via experimentation. I collected whatever old lap top batteries I could find,split them open and removed the 18650 cells. Then soldered them together into the desired voltage (14.8 ish).

These batteries I made were not very useful from a practical perspective, but were extremely useful in teaching me about how lithium battery packs work.

In general, I think Don is right. It's just a bunch of cells soldered together until the desired amperage and voltage is achieved.

No doubt the quality of the cells can vary, the quality of the soldering and the battery management system vary, but at its core, I think most of these batteries are pretty similar in construction.

colemj

· #14 · 3 d ago

Arcb said:
In general, I think Don is right. It's just a bunch of cells soldered together until the desired amperage and voltage is achieved.

No doubt the quality of the cells can vary, the quality of the soldering and the battery management system vary, but at its core, I think most of these batteries are pretty similar in construction.

No.

Well, Battleborn does use a bunch of cylindrical cells, and there are probably a few more, but almost all LFP batteries used on boats and EVs are constructed from prismatic cells.

The quality of these cells can vary, but that is primarily a consequence of them being sorted by QA in the factory, and "failed" or "not top grade" cells being sold off to other resellers and put on the market. It has very little to do with the manufacturing or manufacturer itself.

There is no soldering in prismatic cells or batteries made from them. Even the cylindrical cells are welded, not soldered.

The battery management systems do vary but not by much in these types of drop ins. The more expensive ones might have a bit more robust BMS's, but one never knows because they are hidden from the user.

Your experience with laptop lithium batteries has no relevance at all to the LFP batteries being used in vehicles and boats. They are different formats, different chemistries, different electrical properties.

Look, I apologize for being pedantic on LFP threads, but there is so much bad and even dangerous misinformation around LFP, and all of it arises from people who have zero experience with LFP. While that sounds like "who cares", the reality is this type of confusion is getting back to insurance companies, shade tree installers, magazine article factories, etc and gets reinforced, redistributed, and codified in ways that harm users and industries.

So, if one doesn't have actual experience with LFP, then they should be asking questions and learning and not providing answers or opinions.

Mark

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Don L

Discussion Starter · #15 · 3 d ago

You know what?

I never exactly knew what was in the boxes of my lead acid batteries. I don't see a reason to care.

I feel the real problem with Lithium batteries rep among boaters comes from the first users who turned it into a science project. Just read some threads of how complex they made it sound. I originally ordered a LFP 3 years ago and then the people here on SN scared me enough with "needed changes" that I cancelled that order and got the FireFly. So if people had just shut up I wouldn't have wasted that $2k.

6 months now with "cheap" LFP batteries and I made NO physical changes to my boat. Still have the same battery charger/inverter, same alternator/regulator, same solar controller and same lead acid start battery. None of these has a "lithium" setting so I just reprogramed the solar controller and the regulator and changed the battery charger to a "AGM1", which for it is 14.1/13.4V for boost and float as that seemed just fine. Only run the battery charger if needed when at anchor and have only turned on twice the last month while in a slip with power. I added no additional equipment like DC-DC chargers etc.

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oldmanmirage

· #16 · 3 d ago

Don has pretty much got me sold. I was going to buy another pair of golf cart batts - for a total of 4, giving me a total of 460 Ah/Hrs - before I actually set off.

But I'm pretty sure I'll go ahead and spring the bucks for 4 100Ah/Hr lithiums, giving me a total of I don't know exactly how much - supposedly 400 Ah/Hrs - but more than the Duracells.

Now I just gotta figure out which ones ! I'll probably buy the cheapest ones off Amazon too.

Like these...
Amazon.com: BtrPower 12V 100AH Lithium Battery,5000+ Deep Cycle LiFePO4 Battery with Built-in 100A BMS fit for Home Storage,Trolling Motor,RV,Off-Grid System,Solar Power System,Marine : Automotive

Or these....Amazon.com: DJLBERMPW 12V 100Ah LiFePO4 Battery 12V Lithium Batteries Built-in 100A BMS 1280W Power Trolling Motor Battery 4000+ Deep Cycle Lithium Iron Phosphate Battery for Solar,RV,Golf Cart,Off-Grid,Marine : Automotive

And I can change my solar controller the same way.

4arch

· #17 · 3 d ago

oldmanmirage said:
Now I just gotta figure out which ones ! I'll probably buy the cheapest ones off Amazon too.

I just picked up 2x LiTime 200Ah for $1070 shipped. I got them off eBay as they were $100 cheaper through the same seller as use on Amazon (almost all these batteries come from 3rd party sellers). I did a ton of research and this brand has held a consistent build quality through 2 or 3 years of the company's existence. LiTime (formerly AmpereTime) have received numerous great reviews from Will Proswe and have even gotten a thumbs up from Rod Collins and the Panbo blog. 2x 200Ah will result in fewer connections and less cabling than 4x 100Ah while still providing redundancy.

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Don L

Discussion Starter · #18 · 3 d ago

I can not believe how many more "manufacturers" there are on Amazon now than just 6 months ago when I got my Power Queens.

While I feel they probably are all the same I would get ones that have been around a little longer like the Li-Time ones even if $30 more. If you have time there are Wil Powers tear apart vids on U-tube. After you want a few you realize there is no real way to know what to expect.

Also there are now cheap drop-ins that the BMS has Bluetooth. If not much more those should be considered so you can have better monitoring.

Arcb

· #19 · 1 d ago

colemj said:
No.

Well, Battleborn does use a bunch of cylindrical cells, and there are probably a few more, but almost all LFP batteries used on boats and EVs are constructed from prismatic cells.

The quality of these cells can vary, but that is primarily a consequence of them being sorted by QA in the factory, and "failed" or "not top grade" cells being sold off to other resellers and put on the market. It has very little to do with the manufacturing or manufacturer itself.

There is no soldering in prismatic cells or batteries made from them. Even the cylindrical cells are welded, not soldered.

The battery management systems do vary but not by much in these types of drop ins. The more expensive ones might have a bit more robust BMS's, but one never knows because they are hidden from the user.

Your experience with laptop lithium batteries has no relevance at all to the LFP batteries being used in vehicles and boats. They are different formats, different chemistries, different electrical properties.

Look, I apologize for being pedantic on LFP threads, but there is so much bad and even dangerous misinformation around LFP, and all of it arises from people who have zero experience with LFP. While that sounds like "who cares", the reality is this type of confusion is getting back to insurance companies, shade tree installers, magazine article factories, etc and gets reinforced, redistributed, and codified in ways that harm users and industries.

So, if one doesn't have actual experience with LFP, then they should be asking questions and learning and not providing answers or opinions.

Mark

You know all my boats run off LFP and solar only, no internal combustion systems on any of my boats?

I said "When I first got interested in Lithium batteries I did some of my own research via experimentation. I collected whatever old lap top batteries I could find,split them open and removed the 18650 cells. "

That was when I "first got interested", there was value in that early experimentation for me, but it isn't what I am doing now.

Don L

Discussion Starter · #20 · 22 h ago

Well i am off the boat for a week and my cheap batteries will have no supervisor. I have left boat for a week many times over the years and just trusted solar to work out, but this the first time for these batteries. Could have turned on the charger, but leaving that on worries me more than just leaving the solar and batteries to themselves.

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