New EW 280 AH LFE Batteries - Comments and Questions

[Diep]

We recently received a set of (3) Eco-Worthy 280AH LiFePO4 batteries. These were purchased for $319.99 EA with free shipping and arrived in about 3 days.

Batteries arrived in good condition. Popped right up on bluetooth and had about 40% charge. No much to remark about externally. Quality appears decent, I'm sure some other batteries are a lot more rugged but these are fine for where they are going to be mounted.

Overkill says the BMS manufacturer is DGJBD with firmware version 6.6. Batteries manufactured in December 2024.

We put an adjustable power supply on the first one and it has been soaking up 10A for a long time. One "strange" thing happened is the battery jumped from ~ 60% and 10 hours to full to 99% and minutes to full very rapidly. However it keeps absorbing 10A.

I used overkill to interrogate the BMS and the SOC/voltage entries seem a little off to me. The battery reports fully charged because the cell voltages are over 3.35 but they are a long way from 3.6 (Power supply is set at 14.400).

As I understand it, the settings don't affect the battery behavior but only the SOC reporting. I am wondering if it is best to just stick with this or try to change the values to something else. I'm a little hesitant to change the BMS. Thoughts?

I was planning to push the batteries full and make sure cells are balanced. I was also going to try and check for FCP but it looks like a JBD so should be ok?

Cell Full 3.55v
Cell minimum 2.800

 

[Barking Sands]

If its a JBD BMS you should be good on FCP.

Those charts that have % and SOC next to them I believe are only there for reference in some circumstances. From what I remember one of those circumstances are on a fresh unused BMS. So at this point it may have been referenced and thats the reason for the choppy SOC. After cycling I believe it will use coulomb counting method via an internal shunt. I would leave them alone for now and do a full charge to 14.4 or so and check on cell voltage differential and look for balancing. If they are off balance the JBD is the kind of BMS that you can "let it cook" overnight at something like 14.2 to 14.4. Most of the time when you check in the am cell diff will be less than .010 mV. or at least greatly improved,

Then discharge the battery under some load and check SOC. Recharge to 14.2 or so and check SOC at the top.

 

[Diep]

Awesome, sounds good. So far trucking along up to 3.405v average. Vdiff had been around 0.001 until recently, starting to see up to 0.007. I don't want to let it run overnight without watching so I am guessing it will take another day tomorrow sipping 10 amps to get the first one full.

 

[Diep]

Well I guess they call it a knee for a reason. Cell voltages started rising rapidly and charge current dropped. The cells started to really deviate and started showing 3 high cells into balance mode.

It charged until about 14.25 with a high cell over 3.7 and a laggard back at 3.43 or so. The 3.7 tripped the charge mosfet. I discharged the battery a bit to get it to reset and put the power supply back on and it tripped again. I didn't see where it was the second time.

The battery is sitting right at 14v with a diff of 0.218. It shows it is balancing so I am going to let it sit overnight and see if it evens out at all.

 

[North Baltic sea]

We recently received a set of (3) Eco-Worthy 280AH LiFePO4 batteries. These were purchased for $319.99 EA with free shipping and arrived in about 3 days.

Batteries arrived in good condition. Popped right up on bluetooth and had about 40% charge. No much to remark about externally. Quality appears decent, I'm sure some other batteries are a lot more rugged but these are fine for where they are going to be mounted.

Overkill says the BMS manufacturer is DGJBD with firmware version 6.6. Batteries manufactured in December 2024.

We put an adjustable power supply on the first one and it has been soaking up 10A for a long time. One "strange" thing happened is the battery jumped from ~ 60% and 10 hours to full to 99% and minutes to full very rapidly. However it keeps absorbing 10A.

I used overkill to interrogate the BMS and the SOC/voltage entries seem a little off to me. The battery reports fully charged because the cell voltages are over 3.35 but they are a long way from 3.6 (Power supply is set at 14.400).

As I understand it, the settings don't affect the battery behavior but only the SOC reporting. I am wondering if it is best to just stick with this or try to change the values to something else. I'm a little hesitant to change the BMS. Thoughts?

I was planning to push the batteries full and make sure cells are balanced. I was also going to try and check for FCP but it looks like a JBD so should be ok?

Cell Full 3.55v
Cell minimum 2.800

View attachment 168908

Did you check that all three batteries had exactly the same voltage before connecting them together? This is very important for the balance of the entire bank and for successful maximum charging.

 

[Frosty]

Did you check that all three batteries had exactly the same voltage before connecting them together? This is very important for the balance of the entire bank and for successful maximum charging.

That's interesting. My particular batteries' (not Ecoworthy) manual specifies that procedure must be done only if the bank will be wired in series. That is, if they are going to be connected in series, each battery must be charged individually before connecting them for the first time.

They don't specify that for a parallel installation however, and say you can initially charge those already wired as a bank.

That said, in the intro to that whole section of the manual, the verbiage is "especially if they will be connected in series," so I did it anyway, even though my installation is parallel.

 

[Diep]

The batteries are not connected yet, just working them individually on the bench.

The plan is to leave them all in a comparable state before joining the bank. However I agree it is less critical in a parallel bank than for a series bank as Frosty points out. In a series bank we would probably want an external balancer as part of the install.

Battery 1 sat overnight Vdiff has reduced to 0.01v with Vavg of 3.369. The charger has been on battery 2 all night but when it frees up I plan to put it back on battery 1 and try to bring it up again and see if the balance is improved at the top.

Interestingly, Battery 2 has shown a more reasonable SOC throughout the charge cycle so far. Its a couple hours away from topping out so there should be some results on that one before long.

 

[bglad]

Is it common/normal that a cell could rise to 3.7 (14.8) volts using a 14.4 power supply?

 

[Barking Sands]

Is it common/normal that a cell could rise to 3.7 (14.8) volts using a 14.4 power supply?

On the first charge or two its very common. But usually, it will only be one cell or two. The total voltage of all cells can not be over 14.4.

 

[Diep]

Battery 2 just got to the top. Tripped the charge mosfet at 3.750 on the high cell with 3.452, 3.459, 3.607 for the other 3 and 14.268 battery voltage. I am letting it cook some off with the internal balancer. Charger is back on battery 1 to see how it tops up on the second pass after balancing itself last night.

 

[Diep]

Battery 1 got to 14.404v with a max differential of 0.011. Don't know when it got there but somewhere between hour 5 and 12.
Battery 2 is at the same state right now after about 3.5 hours. Might leave it a bit longer and see if it gets better. Then move on to do the same for battery 3.

It will be a little while before I put these in service. A month to 6 weeks probably before they can get cycled for real. I am thinking I should get a load on them and pull them down at least 10%.

 

[Barking Sands]

Good deal. I would load them and discharge them just to watch them towards the low range to look for any other anomalies that might spring up. Would probably take them down to 11 volts under a small load. Make sure there is no cell or pack anomalies at the low end. May as well test them now in case there is any warranty issues.

 

[Frosty]

This thread reminds me about something I've been curious about. So I've only bought/commissioned six brand new LFP batteries, but they all just charged right up to 100% right out of the box, and were balanced to no more than .01 difference between the highest and lowest cell.

Did I just get lucky? Or is it because they are smaller batteries (200ah). Is this more typical of batteries that are larger in terms of ah? I guess now I know it's okay, but at the time I would have freaked out if they had kept shutting off.

 

[tiltrider1]

This thread reminds me about something I've been curious about. So I've only bought/commissioned six brand new LFP batteries, but they all just charged right up to 100% right out of the box, and were balanced to no more than .01 difference between the highest and lowest cell.

Did I just get lucky? Or is it because they are smaller batteries (200ah). Is this more typical of batteries that are larger in terms of ah? I guess now I know it's okay, but at the time I would have freaked out if they had kept shutting off.

Same here, bought 4 EW260ah batteries hooked them up and watched them all balance out. Although testing before installing for warranty reasons does make sense.

 

[Frosty]

Same here, bought 4 EW260ah batteries hooked them up and watched them all balance out. Although testing before installing for warranty reasons does make sense.

Well I did charge mine up individually on the bench, just to make sure all was okay. But same result.

 

[Barking Sands]

Many times the balance resistors in these bms are roughly the same size regardless of cell capacity. So the "authority" to balance the 4 cells in a 12 volt pack would vary by cell size. Much easier for the same balance resistor to balance a 100ah cell than 2x230 ah cells.
In addition charge rate will come into play. If you charge with 10 amps total and the balance resistor can apply a 100mA correction that will be more effective than a 100 amp charge rate as it pushes into the upper knee with lots of current.

Also, what final absorption voltage is also comes into play. If you set absorption voltage to 14.6 with a 100 amp charge rate you will blast into the upper knee and across most of the
upper knee with many charge amps applied. Only tapering as you approch 14.6v. Contrast that with the same 100 amps but with absorption set to 14v. You will enter into the upper knee much more gently and current will naturally fall as you approach 14v target. Imo this is likely to reduce the observed cell split through a charge cycle.

And yes you can also just get lucky...lol. but there are quite a few factors that might make your initial charge vary in regard to v-diff.

I always say....it doesn't much matter what vdiff is the first 5 charge cycles look like...its the next 3000 that count.

As long as your vdiff is reducing in the beginning and then finds an equilibrium, and then never grows over time...imo your just fine.

 

[NoRain]

Just to offer a real life experience….I installed 4 x EW280 in June. They looked very good right out of the box so installed them all at once and turned the MultiPlus on. Left for a day or two and they were behaving exactly as expected. Went through a couple 40%-ish discharge cycles, and then a deep draw. The OverKill reading are from just before the pic of the shunt readings. 12.64V at 8% SOC while pulling 93A. I was very impressed needless to say. Let them fully recharge over a day or two and pulled them down to 10% again. Similar observations. I can’t imagine how hard I would have had to load to get them to 11V! I then left for 3 months cruising, mostly off-grid. They performed beautifully in every possible regard.

Disclaimer: I am aware that having said the above out loud I may have angered the gods and it will all go down the toilet. But I type this with one hand, the other having crossed fingers, and a ring of garlic around my neck. I will be attentive for any negative indications from the gods and have a lamb ready to be sacrificed. My tech and nautical background tells me that’s pretty much all that can be done.

 

[Frosty]

Thanks, @Barking Sands for all the information. I really like learning more about how things work.

I know it's a slight tangent, but I have a question for you. So my battery bank just has one BMS (external). That tells me the actual balancing circuitry must obviously be inside each battery individually, and not part of the BMS.

I'm just trying to get my mind around the differences between one BMS per battery (inside) vs. one BMS per bank (outside) like I have.

Say I had three batteries in a parallel bank, but one external BMS. Is the BMS is able to act on one battery separately? If a cell in one battery gets too high say? I guess I don't know that because I haven't had one battery individually misbehave or get out of balance. The only real-world "BMS command" I have had was a "Sorry, it's too cold to charge so we have turned that ability off." But of course that applied to the whole bank, not one individual battery.

Frosty

PS: BTW, I was initial charging at around 30 amps/12 volts (so as you say, fairly small charge amps).

 

[Diep]

Since it will add to the discussion...

On battery 1 I actually charged it a little too hard. When the charge amps started dropping below 10a (the power supply max) the voltage at the terminals was still well below 14.4. Since the power supply had switched over to constant voltage I thought I was seeing loss in the weenie cables on the power supply. So I started boosting the voltage a bit to keep pushing 10A. I was really watching it close though and never let it above 14.4 at the terminals. As it went the delta between the PS and the terminals was closing and I realized I was doing a constant current regime which wasn't right. I pulled it back to 14.4 and let it finish.

So on battery 1 I think I forced it and then it took more time to balance it. Battery 2 I set it and forget it at 14.4. It still tripped the mosfet on the first pass but then it balanced much faster on round 2 without tripping the charge mosfet again.

I haven't done 3 yet but I will probably do that one at 14.2 until it is full and balanced. Then bump it up to 14.4. I'll bet if I do that it won't ever trip.

 

[Barking Sands]

Thanks, @Barking Sands for all the information. I really like learning more about how things work.

I know it's a slight tangent, but I have a question for you. So my battery bank just has one BMS (external). That tells me the actual balancing circuitry must obviously be inside each battery individually, and not part of the BMS.

I'm just trying to get my mind around the differences between one BMS per battery (inside) vs. one BMS per bank (outside) like I have.

Say I had three batteries in a parallel bank, but one external BMS. Is the BMS is able to act on one battery separately? If a cell in one battery gets too high say? I guess I don't know that because I haven't had one battery individually misbehave or get out of balance. The only real-world "BMS command" I have had was a "Sorry, it's too cold to charge so we have turned that ability off." But of course that applied to the whole bank, not one individual battery.

Frosty

PS: BTW, I was initial charging at around 30 amps/12 volts (so as you say, fairly small charge amps).

Frosty...what batteries and external BMS do you have?

 

[Frosty]

Frosty...what batteries and external BMS do you have?

They are Victron 12.8 Smart LFP, 200ah apiece. Not the NG but I guess you could now say the "classic" ones. In one installation (boat) I only have one battery, so it's one BMS, one battery. But in another setup there are three of (the same) batteries, and of course still only one BMS. I just got to thinking about how things might differ with one BMS controlling multiple batteries (which obviously though, each battery must have their balancers inside). Vs. batteries with built in BMS's, where each battery has a separate BMS.

(I do carry a spare BMS.)

 

[NoRain]

Off the top of my head Frosty - multiple BMSs give you access to more capacity from each battery eg the limiting factor in trying to pull amps out of a LFP battery is the BMS, not the battery chemistry, and 2) a safety/security factor if you have multiples in a house bank; an “problem” with one battery could cause a BMS shutdown, which would only take that battery offline, still leaving the remainder participating in the bank. Also preventing a sudden bank disconnect to an alternator.

 

[Frosty]

Off the top of my head Frosty - multiple BMSs give you access to more capacity from each battery eg the limiting factor in trying to pull amps out of a LFP battery is the BMS, not the battery chemistry,

That's interesting. Victron rates the batteries for X amp hour draw and does not make any distinction if you have more than one battery in the bank (which would still only have one BMS). That leads me to believe it's the circuits (or whatever is) inside the battery that account for the rating and not the BMS -- at least in this case. Edited to add: I looked on the datasheet and you can have up to 20 batteries per setup.

One reason I got these batteries is they have a pretty good rating for amp draw, and I wanted to be able to do an emergency start if necessary.

and 2) a safety/security factor if you have multiples in a house bank; an “problem” with one battery could cause a BMS shutdown, which would only take that battery offline, still leaving the remainder participating in the bank.

I guess I could see that. Actually that was kind of my question. i.e. when you have one BMS and multiple batteries, is it all or nothing (without moving wires), or can the BMS react to only one battery (I'm guessing not). I would have to "unwire" one battery from the bank if only one truly became toast for some reason. On the other hand, I can easily carry a spare BMS, so I guess on that count I gain reduncancy.

Also preventing a sudden bank disconnect to an alternator.

I think I'm covered on that though (?). The BMS is wired to each charger (solar, alternator, shore) (with a signal wire) and can "send out a message" to them all to stop charging before there is a disconnect. I also get a pre-alarm.

Also in my case I have an AGM start battery, so that is always there to soak up charge.

But I'm always open to learning more about how they work. I had a simple reason for choosing this setup: I could fit 200ah into the space available. Secondarily, it was rated highly enough to start my engine if need be. There is additional "stuff" to fit due to the external BMS, but I could fit those things into much smaller odd-shaped spaces vs. a larger/bulkier battery.

 

[l00smarble]

This gets complicated and is difficult to summarize in a quick post but Victron has numerous different BMS options. Other than the Lynx Smart BMS they work very differently than internal BMSs. The Victron BMS does not handle the current of the load/charging - rather it gives instructions to other devices to manage the load/charging with two main toggles based on a variety of monitored parameters like voltages, temperature, etc. The BMS will instruct "allowed to charge" yes or no and "allowed to discharge" yes or no. For example a VE.Bus BMS will simply tell a Multiplus or Quattro to stop inverting if the voltage gets too low or it will tell the Multiplus that it is not allowed to charge if the temperature is too low. Same instruction to the Victron MPPT and to a CAN-BUS enabled alternator regulator.

A proper Victron system with Victron batteries will need loads connected by a BatteryProtect or a relay/solenoid wired so that if "allowed to discharge" is false, the load is disconnected.

The cell monitoring and cell balancing is indeed inside each battery then the batteries have daisy chained data cables that bring that data and allow control by the BMS. There no MOSFETs in the battery to block currents in either direction but also this means no current limitations due to MOSFETs.

It is true that usually the limitation in current of a LFP battery is the BMS but with a Victron setup the BMS does not carry the current so the discharge or charge current can be FAR greater. For the batteries like Frosty has the allowed discharge current is 2C and the "recommended" is 1C. So 3x200ah Victron batteries can deliver 1,200 amps rated max but it is recommened to keep it more to 600 amps.

The eco-worthy 280ah has a max discharge of 200a. If Victron made a 280ah battery the max (2C) discharge current would be 560a comparatively.

 

[Frosty]

This gets complicated and is difficult to summarize in a quick post but Victron has numerous different BMS options.

You did a great job here. Thank you!

Other than the Lynx Smart BMS they work very differently than internal BMSs.

Just as a note, I don't have the Lynx BMS. I actually have the Small BMS (system with no inverter/charger). So the most basic, but totally fine for my system(s).

The Victron BMS does not handle the current of the load/charging - rather it gives instructions to other devices to manage the load/charging with two main toggles based on a variety of monitored parameters like voltages, temperature, etc. The BMS will instruct "allowed to charge" yes or no and "allowed to discharge" yes or no. For example a VE.Bus BMS will simply tell a Multiplus or Quattro to stop inverting if the voltage gets too low or it will tell the Multiplus that it is not allowed to charge if the temperature is too low. Same instruction to the Victron MPPT and to a CAN-BUS enabled alternator regulator.

Thank you for explaining that so clearly. I did "know" that back in the beginning, but started to doubt myself based on most threads now being about internal BMS batteries. But so right, the BMS doesn't "do" anything; it simply gives instructions to other things (Battery Protect, Solar controller, B2B charger, shore charger, etc.)

A proper Victron system with Victron batteries will need loads connected by a BatteryProtect or a relay/solenoid wired so that if "allowed to discharge" is false, the load is disconnected.

Right. I do have one large BP for my loads, and then all the charging devices but one can accept a signal wire. The one that cannot accept a signal wire has a smaller BP wired "backwards" so that the current flows the correct way.

The cell monitoring and cell balancing is indeed inside each battery then the batteries have daisy chained data cables that bring that data and allow control by the BMS. There no MOSFETs in the battery to block currents in either direction but also this means no current limitations due to MOSFETs.

Aha! I wondered why these batteries had such generous continuous discharge ratings for their size. I mean, I went by their datasheet, but didn't exactly understand why it was the way it was.

It is true that usually the limitation in current of a LFP battery is the BMS but with a Victron setup the BMS does not carry the current so the discharge or charge current can be FAR greater. For the batteries like Frosty has the allowed discharge current is 2C and the "recommended" is 1C. So 3x200ah Victron batteries can deliver 1,200 amps rated max but it is recommened to keep it more to 600 amps.

This (and even more the physical size per/ah) is why I chose them (and why a buddy chose them when we re-did his boat).

I will say that these are not the cheapest batteries per amp hour. OTOH, Victron did lower their prices quite a bit about 1.5 years ago, to stay somewhat competitive, which was nice. I mean they also aren't in the stratosphere like some others I considered. But mainly, they fit in the space I had.

I do also like the control (the ATC wires, etc.), the form factor, and the large allowed discharge rating. Also that they have the recommended certifications and a good manual/documentation.

To be fair though, because the control devices and BMS are on the outside, you have to put them someplace and tidy/support the various cables and small wires. For me I could find spaces to fit those, but not another or a different sized "large box" (battery). And I like that I can carry a spare BMS and spare BP.

Anyway, thank you so much @l00smarble for explaining it so well! I appreciate it, and perhaps for some other people who might not have known that external BMS batteries are available and have some plusses this will be useful.

 

[Barking Sands]

Great outline above in regard to the Victron set up. Here is another good write up from ben Stein regarding some of the aspect sof the Victron system and BMS's

Victron NG Smart LiFePO4 batteries, ultimate power flexibility

If you made a list of all the features you require and prefer in your boat's batteries, I would bet that Victron's NG Smart batteries would check just about every item on your list. In a field where it sometimes feels like we are all field testing products, Victron's batteries, BMSes, and...

panbo.com

 

[Frosty]

Just to note, the write-up is on the NG (new generation) batteries. They came out around a year ago.

They do use an external BMS, same as the (I guess we will now call them) "classic" Victron LFP batteries do. (These are what I have.)

We did consider the NG batteries for the re-do of my buddy's electrical system about a year ago, as they had just come available at that time, but.... for his relatively simple system, the extra features (and, eg. required $1,000 BMS vs. the $50 SmallBms for the classic batteries) didn't make sense.

Ohhh, I have to edit here. I see there is now a "SmallBMS NG" that is only ~$80. That wasn't available last fall (only the $1000 BMS which was very nifty but totally above what was needed).

Ha ha, now I have to drool over the NG.
OK, drooling ceased rather quickly.... wow have prices gone up (even for the now "classic" aka old batteries). Not that they aren't really nifty though. Excuse me while I go put on kid gloves to take care of the ones I have.

 

[Barking Sands]

Just to note, the write-up is on the NG (new generation) batteries. They came out around a year ago.

They do use an external BMS, same as the (I guess we will now call them) "classic" Victron LFP batteries do. (These are what I have.)

Ha ha, now I have to drool over the NG.
OK, drooling ceased rather quickly.... wow have prices gone up (even for the now "classic" aka old batteries). Not that they aren't really nifty though. Excuse me while I go put on kid gloves to take care of the ones I have.

Did you see he combined the NG and the classic? Pretty cool testing.

 

[Frosty]

Did you see he combined the NG and the classic? Pretty cool testing.

Oh I missed that. Even read/skimming it twice, geez. I'll have to go back and read it more thoroughly.

 

[Barking Sands]

Oh I missed that. Even read/skimming it twice, geez. I'll have to go back and read it more thoroughly.

Actually I dont think he did it in the test but alluded to the fact that it could be done by using more than one BMS and creating "virtual batteries". So in theory you could add another set of NG batteries with its own BMS and essentially have 2 "virtual batteries" reporting and being controlled.

During normal operations, the main difference with virtual batteries is the rolled up reporting displayed for the virtual battery. Virtual batteries allow mixing of both Lynx Smart BMSs and Lynx Smart NG BMSs. However, Smart batteries need to be behind a Smart BMS and NG batteries behind a Smart NG BMS. Additionally, you can only combine BMSs with the same current handling ratings.

Of course an all Victron system is still the most developed and complete system IMO.