Battle Born LFP impressions

[PNjunction]

Just some impressions from what I've seen online. I like what I see, but I am not an owner. I am only evaluating it from a "stand alone" drop-in, NOT from a series/parallel standpoint.

After reviewing several teardowns, and interviews online, I must say I like what I see. It's what I do from a diy LFP-ninja standpoint.

Up front: Look, a BMS is a fact of life. *I* can do without, but for normal people who have neither the time, energy, or skill to deal with lfp battery systems, and subject it to any weird load under the sun, it's mandatory. It protects the user, the product, and most importantly, the WARRANTY. I've read it, and it is reasonable. The BMS is intended to keep the product usable in unskilled hands, and perhaps cut down on the reprehensible battery-scammer who wants "free batteries for life" with purposeful abuse.

A future owner should read the manual and warranty. Basically these guys just want you to enjoy the system, and oh yeah, STAY in business. Standard stuff.

Cylindrical cells that are matched. I certainly get it here. Unlike a prismatic where a bunch of flat-packs are connected internally, there is no way to QC that unless you are the actual manufacturer. It is easy for a poorly performing flat-pack cell to "hide". And sometimes, puff-up under abuse and take out neighboring cells. Cylindricals with their inherent already tight-compression, tend to just die on the vine. And now it is much easier to do your OWN QC and matching to reject outliers so they can't hide amongst the others.

Under-spec's: I love how they are not cutting things so close to the edge in stated capacity. One thing we as solar guys know is not to cut things too close. Give yourself an edge to accomodate errors in power-budgets, component aging, and so forth. Think about how the system will perform years from now, not just at initial startup. The system is obviously top-balanced, and by under-specifying capacity, this gives you a little breathing room for a little ragged balance down below so as not to hurt the cells - despite the bms lvd. I get it - I understand.

Proprietary wrappers - if they want to stay in business they won't be using junk. BUT, by not specifically identifying the cells, this allows them not to be locked into a single supplier. I get it - I'd like to know from an enthusiast standpoint, but then there's the "I want to stay in business" standpoint too, and not get hoodwinked by supplier / chain issues. From seeing what they are doing, it certainly doesn't look like they are going to bet the farm on junk cells and shoot themselves in the foot.

Solid engineering: Something that I mentioned many years ago - these aren't some guys just tossing cells rattling around inside the box, wired up with speaker wire and calling it a day.

Temp sensor - I love seeing the temp sensor that will allow for sub-freezing DIScharge, but stop you from trying to CHARGE under freezing conditions. Again, protecting the product from possible user abuse - accidental or otherwise.

Common Sense Tips: Overall LFP knowledge is evident. Simple warnings like if you hit the bms self-protect, don't let it sit around like that or further discharge (internally beyond the bms cutoff) will hurt them. Solar - tip about not letting the system go into total bms disconnect, otherwise your solar system may disconnect and not reconnect properly seeing what it thinks is a battery removal.

Obviously, here the thing to do is not use your bms-disconnect as your SOLE LVD all the time.

I've reached kind of a real-world middle ground here regarding drop-in's. I can do it myself, but if my Uncle were to need a 100ah LFP, I wouldn't feel guilty recommending a Battle Born.

I could go on, but basically from a drop-in standpoint, from what I've seen - I'm impressed. It's how I would build it if I had to give one to someone who is not a diy-maven.

[SunEagle]

It looks like those batteries are not as expensive as other Li chemistry.

I guess my big question is will they provide 3000 cycles with a 100% DOD?

If so that 100Ah 12V battery can get you a source that will provide power for its life at less than $0.28/kWh.

[PNjunction]

Good points!

To actually make a dent in the lead-acid game, LFP, the easiest of lithium cells to make, should be much lower in price compared to non-lfp types. But that's not going to happen - the consumer doesn't really know the difference between nominal 3.2v lfp cells, and nominal 3.7v (non-lfp) types. Lowering the price of LFP would require an across-the-board industry sea-change.

So what's left is the usual capacity vs cycles which consumers can understand.

Which leads us to: We all know that merely doing cycles "sausage-factory" style cycling over and over during testing is not really accurate as Prof Jeffrey Dahn has pointed out. Especially if one is going to demonstrate a warranty like after 8 years. But at least it seems these guys UNDER-spec their cells, which tends to help if one is going to be a battery-hoarder. Not that I recommend that.

My own years long testing of my prismatics showed that despite meticulous care, sure enough batteries age. Even LFP. So it would not be reasonable to say purchase one now, store it for 8 years - even properly - and then expect the 3000 cycle life span immediately afterwards. Ie, only buy a battery when you actually need it.

But overall, I think that there is much less of a chance of your average punter not properly maintaining one of these, as compared to undercharging and sulfating a lead-acid battery. I know I get the most out of my lead-acid purchases, but my neighbor - not so much.

High upfront cost - I see something similar to say how Enersys products are handled. Kind of a filter to prevent a casual person ignorant of the very basics of batteries trying to power his air-conditioner with a 12v inverter that he got from the auto-parts store - and wired up with finger tight random bolts. The warranty guidelines are similar.

It's hard for me - mr "no bms", fully cognizant of how mosfets can fail closed and all the balancing issues can rear their heads - to be cool with this on a consumer basis.

In other words, for the average Joe who has a life beyond battery mainenance, maybe their smaller 50ah battery would make a good "learner battery" for solar use. If you can swing that (upfront costs of course), then maybe you'd be ready for a larger series / parallel bank down the line.

[Ampster]

Isn't one of the advantages of these drop in batteries that you can incrementally expand your pack with more parallel batteries without worrying about the same imbalance issues you would have with Lead Acid chemistries.?

[PNjunction]

Incrementally expand like lego's as time goes on? Not recommended. Best to do a power-budget and build accordingly at the outset. Maybe ask them if a particular application in mind would be ok for that.

Why?

Aging and use of say a single battery, and two years later you tack on a new one ... the more "mature" battery with cycles on it will take more of the brunt of the load from cycle to cycle. And affect the new one. Just because it is LFP doesn't make it significantly different than lead acid in this regard.

Can you get away with it? Sure - depends on the application. And what sneaks up on you here is the flat discharge curve where you think things are rosy - unlike lead-acid where voltage drop differences are more accute when you do this.

Since most of us can't determine internal resistance, IF one is going to do this, then be sure to watch terminal temperatures if nothing else. Get one of those temperature guns with a laser-pointer in it. Welcome to more maintenance beyond the usual. Entering *very* diy territory.

I do love how they supply the bolts and adapters, and are adamant about using specific torque! Not just finger tight. Assuming one has those tight, even so, it is just not good engineering to mix and match old and new. From AA's to 48v monster banks. Unless you are prepared (and your wallet can take the hit) of replacing the weak-link (older affecting the newer) over and over.

Sadly, that's a utopian vision. Nobody in the industry does this, unless it is for emergency temporary restoral. Long term -not good - but some find out the hard / expensive way.

So now the smaller 50ah "learner battery" they have is still just that. An auxiliary if you will. Might come in handy.

[Ampster]

........
Why?

Aging and use of say a single battery, and two years later you tack on a new one ... the more "mature" battery with cycles on it will take more of the brunt of the load from cycle to cycle. And affect the new one. Just because it is LFP doesn't make it significantly different than lead acid in this regard.
......

I understand how this is a killer with lead acid, because lead acid doesn't tolerate partial charging. Lithium doesn't care if it is partially charged.

On the other hand with the BMS on each pack if the weaker battery gets full before the stronger one and the charger keeps going won't the BMS on the fully charged weak battery take it off line? I can see how that might put unnecessary wear and tear on the BMS. If it were to fail to open the HVD, then I can see how the older weaker battery could get over charged.

I agree with your premise that it is not a good idea to put batteries of different vintages in parallel. I am just wondering if these batteries might be a little more tolerant than Lead acid?

[PNjunction]

Maybe a mental exercise might help that goes to the extreme to amplify the effect:

Make a 4S / 48v, 100ah bank with 4 of their batteries. Assume you have done the right thing and charged each individually first before doing so etc - standard procedure.

Now remove one of the batteries, but replace one with their 50ah model. Just for discussion obviously.

That 50ah battery (or one of the 4S cells if you want to look at it like that) will be worked hard, much harder than the rest. But also when you charge it back up, say you only wanted to charge to 90% full, since we don't need a totally full charge all the time.

That 50ah cell will always be in balancing mode, and riding out the CV stage to 100% capacity. Basically the cells are going to act / age differently than the rest of the system.

Since the bms' don't communicate with each other, eventually this situation *may* be of concern depending on your application and how critical it is. Out at sea? On a wheelchair 10 miles from home and your cellphone doesn't work?

Probably the best thing to do is ask them, and not rely on my internet analogies.

Ultimately, the warranty decides all. Does such mix-n-match as convenient void it?

[SunEagle]

Maybe a mental exercise might help that goes to the extreme to amplify the effect:

Make a 4S / 48v, 100ah bank with 4 of their batteries. Assume you have done the right thing and charged each individually first before doing so etc - standard procedure.

Now remove one of the batteries, but replace one with their 50ah model. Just for discussion obviously.

That 50ah battery (or one of the 4S cells if you want to look at it like that) will be worked hard, much harder than the rest. But also when you charge it back up, say you only wanted to charge to 90% full, since we don't need a totally full charge all the time.

That 50ah cell will always be in balancing mode, and riding out the CV stage to 100% capacity. Basically the cells are going to act / age differently than the rest of the system.

Since the bms' don't communicate with each other, eventually this situation *may* be of concern depending on your application and how critical it is. Out at sea? On a wheelchair 10 miles from home and your cellphone doesn't work?

Probably the best thing to do is ask them, and not rely on my internet analogies.

Ultimately, the warranty decides all. Does such mix-n-match as convenient void it?

With those 100Ah being around $1000 each I think that someone would have to have a lot of disposable money to tinker around with them.

[Ampster]

I was actually referring to putting them in parallel to increase pack capacity. Typically one would do that with similar capacity batteries but if one group was slightly older than the rest of the pack within 10% or so. I don't think the degradation would be the same with lithium as even that slight difference would create with Lead acid. That is all I was speculating about. Maybe this is a topic for another thread since it would not be unique to Battle Born

I understand the issues of putting different vintages or capacities in series and your illustration does a good job of explaining why that is not recomended..

[extrafu]

With those 100Ah being around $1000 each I think that someone would have to have a lot of disposable money to tinker around with them.

Omitting the voltage is quite wrong in every Ah battery capacity saying. 100Ah at 3.2v for a single prismatic cell is far away from a 100Ah at 48v. In this case, it's 12V but only saying 100Ah is expensive is misleading.

[SunEagle]

Omitting the voltage is quite wrong in every Ah battery capacity saying. 100Ah at 3.2v for a single prismatic cell is far away from a 100Ah at 48v. In this case, it's 12V but only saying 100Ah is expensive is misleading.

I say it is expensive for 2 x 12v 100Ah battery system at $2000 compared to 2 x 6V 225Ah FLA batteries at $250.

The comparison is will the 100Ah Li battery produce a kWh cheaper then the FLA over their lifetime.

Some people can better afford buying those 2 x 6V @ $250 very four years compared to 2 x 12v 100Ah at $2000 every 8 years

[extrafu]

I say it is expensive for 2 x 12v 100Ah battery system at $2000 compared to 2 x 6V 225Ah FLA batteries at $250.

The comparison is will the 100Ah Li battery produce a kWh cheaper then the FLA over their lifetime.

Some people can better afford buying those 2 x 6V @ $250 very four years compared to 2 x 12v 100Ah at $2000 every 8 years

I perfectly agree with you on this.

[PNjunction]

Re: add-ons or replacements in leiu of doing a power budget - now that I think about it from a manufacturer's perspective, I'd probably not to want to limit sales. In that case, it might be simply "not recommended, but not prohibited".

Upfront cost: actually better than most considering how open they are about their manufacturing / testing process. Each cell is measured for capacity, and assuming they are looking for internal resistance outliers too. Then each "mod" as they call it (pack of 3.2v cells) is tested again under those conditions before final assembly. Lots of manual labor there. Far better than someone just pulling cells out of a cardboard box and firing up the spot welder.

In regards to lead-acid -- WE know how to get the most and maintain lead acid properly, but most don't. I alluded earlier that for many, the upfront cost is paid back in less end-user maintenance to keep the battery healthy. So there's that.

Website and videos: I've got my radar up and running, and nothing I see on their site(s) if you include Dragonfly, shows up on my screen as a red-flag. Other than the obligatory green thing and user testimonials, it seems to be on target technically with no BS and limited buzzword marketing. It's funny to watch the CEO, an obvious techy guy hold back when discussing things - which looks like he'd love to get into but doesn't want to make eyeballs glaze.

If I needed one, I'd be very comfortable with Battle Born. If I'm trying to run massive propulsion systems, or life-critical systems, then possibly go into the stratosphere with something like Lithionics, but that's a whole different level of engineering.

Again, as a non-owner, these are just impressions. Impressed enough to like what I see, that's all.

[SunEagle]

I am also impressed with the battery. I just wish all Li chemistry types would be lower in cost and much easier to justify as an energy storage source for solar. Without products coming down in price then most of the people will never be able to use solar at home.

I hope that since pv panel prices have come way down then all other solar based equipment follows. We need to be able to install this equipment and stay inside a financial payback period.

[PNjunction]

Heh, when I first started with prismatics back in 2009 or so, I thought that give them a few years and lead acid would be toast based on the performance differences alone.

But - that didn't happen, and possibly not to threaten the lead-acid industry, the upfront costs remained high, and were touted solely based on cycle life cost. It actually does work out, but it's a longer term outlook.

At the time, I was plenty happy to just replace lead-acid more often. Thanks in part to this very website, I got enough info to actually enjoy proper lead-acid maintenance, be it flooded, gel, agm.

Then along came LFP. Thing is, despite decades of talk, I had to go hands-on. Holy cow.

From a battery-nerd standpoint, LFP took a lot of maintenance fun out of the equation. What? No eq? No hydrometers? No charging a gel to a max of 14.1v cv despite the sticker ratings? Supplying supplemental charging to my agm's simply because solar can't really hack it on a daily cyclic basis? Not worrying about Peukert? My inverters always running very efficiently at nearly dead status? PSOC and not worrying about leaving my battery at 30% SOC and going on a 2 month vacation and basically picking up where I left off with no sulfation? Goofed on your power budget and actually bought too much capacity (yeah, rare) - just psoc it, and not worry about reaching 100% soc all the time.

(Hint - in those PSOC cases, I STILL treat my overly-large capacity battery to a full charge - discharge - recharge about once a year just to make sure the chemicals stay active across the entire surface. Another thread perhaps)

I think that for a battery nerd, this performance aspect - provided you start with a quality product in the first place, be it this or something else - might make the hit on your wallet MUCH easier to swallow.

It truly is mind-blowing, but it takes hands-on to make it sink in for the AHA moment to occur. So just a warning.