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I posted this under a different thread but maybe this is better since it is a review of a Chinese battery supplier - BESTGO batteries. I got mine through Electric Car Parts Company but you may be able to get them through other vendors as well. If this is just supposed to be AliExpress and...

I greatly appreciate your comments. First of all, yes, I constantly test the tester with two other clamp meters and several volt meters and have verified that the rate of discharge and voltage readings are very accurate. And, yes, it does have separate Voltage and Current leads. In terms of...

Unfortunately, I can only offer a negative experience. I bought 64 200Ah "new CALB" cells from Dongguan HuanHuan Energy Technology on Alibaba for about $8400 and they are well below rated capacity, about 165 Ah. There were a number of signs that they had been well used before purchase and the...

I wish I could provide credit for this work but I cannot remember who generated these curves. I believe it was someone on this forum though...Apologies to that person because these are extremely useful. These only cover the range typical in domestic solar charging from 0.2C to 0.05C but the...

I posted this on another location on this site specific to the vendor in question but thought it might be of genera;l interest to anyone currently sourcing batteries. If it's bad form to post in two places, please let me know and I will try to remove one. I was recently made aware of this forum...

Update on my post above. I bought the Bestgo 400Ah 12V battery after many detailed conversations with Tony of Bestgo. I finished capacity testing a couple days ago. With 10A charge rate, starting at 14.6V and terminating at 11.2V (2.8V/cell), the battery produced 430.6Ah capacity, (5.58 kWh)...

I agree with much of what you say here. Part of why I posted was to help others not repeat my mistake of not being able to check capacity before the dispute period runs out. However, others who had the same expereince within the 3 months also were given very little help through Alibaba and none...

Sorry, I reread and you clearly said it protects battery positive, my mistake

wtf dude, that's not at all what i asked. there are people who post youtubes where they have removed the case, etc. that will void the warranty so i am not willing to do that. all i was asking was if anybody who had one apart still was able to test individual cells or the battery without bms...

yes, it is these single tests that i am using to quantify capacity. i've tested almost half now, a little under 165Ah mean with a standard deviation of about 5, high 175AH, low 155Ah. there is no doubt in my mind that these are well under 200Ah. with your and others' helpful information it also...

I am not sure what happened to my earlier post here but I wanted others to know that I recently bought 64 x 200Ah cells from this vendor (dongguan huanhuan energy) and found out that they are only about 165Ah cells. They were guaranteed to be new CALB 200Ah cells. I can provide capacity testing...

of course the seller is going to say that. they told me also that i must be doing something wrong. this is why i think it is necessary for all of us affected to come together. that way we can show the pattern that any one of us will be challenged about.

I thought I'd add that having two identical capacity testers is another good internal check. If one were much different than the other, I should be able to see consistently higher or lower results from one tester which I don't seem to be getting. Also, I had to run an early test over because I...

No, the slopes of the charge curves vary dramatically toward the bottom and top depending on charge rate. Charging at 1C has much more gradual slope towards the top which allows you to push 14.6 (in a 4 cell battery) without issue. At 1C though, 13.6v would only be about 70% charged. I'll try...

I am in the process of transitioning from my 4P16S DIY set up to 3 EG4 batteries. I will have a lot of busbars available within a week or so. You are welcome to many of them for the cost of shipping. I can check length to see if they'll work. I also fabricated a number of short-length jumpers...

I agree with time2 roll about limiting the V to less than recommended. The issue is that at low charge rates, the V to SOC curve gets very steep as you approach full charge. As you approach 14V at slow charge rate, it takes very small increments of power to cause the V to rise. Your battery has...

i'm talking with amy wan about getting some eves from her, i'll ask her what she thinks and report back.

I don't know enough to comment on how the different formulations would affect charge curves but I have watched intently through an embarrassing number of charge events for different LFP batteries and I have found these curves to be very accurate and representative. I have unfortunately not found...

Thanks for that, unfortunately I already ordered a relay (4 actually) that I am hopeful will do the job. The contactor has two sets of tab connections, one of which is diode protected so I will use that set. It's nice to know of the option you provided if the relays I ordered don't work.

This is a great summary!

Thank you, I appreciate that. I chased it down and unless I got the wrong one, it was the same version I had. But, this time I did find the applicable section and their stated difference in life cycles depending on clamping. Very interesting. I have been in discussions with Tony, the main dude...

Don't forget the vendor also promised a one-year warranty. What good is a one-year warranty when problems have to be identified in the first 3 months? I think blacklisting vendors that do not deliver what they promise is not too harsh, it's simply identifying vendors that don't deliver the...

how did you get to those records?

Related question, do the breakers in the EG4 14.3kWh Wallmount units equate to a T-Class fuse or is it advisable to add one between battery and inverter? I'll post this as a new thread if it's not appropriate here. Thank you

thanks much for clarifying all that. he confirmed in emails that he's including all the cables inxkuding two parallel kits. if the eg4-specific rs232 and 485 cables aren't there, I'll have to order them but I'll have to put the batteries online without the firmware update.

i didn't mention the full treatment of the bank but i did do an entire bank top balance (at 3.65V) a while back. the drawdown to 3.05V was just when the system cut out and that gave me a real-world data point for capacity. i assumed there was arpund 6-7% left in the bank at that cutoff and have...

the screenshot is a bmp file. i thought if someone wanted to see it, i could just email or text them, wasn't sure if there would be general interest. i'm sure the spreadsheet would attach but it's a zillion lines (approximately) of data.

i am considering trying a chargery again but just as a simple method to operate high and low cutoffs for an RV battery. i liked its ability to control dc contactors but wasn't crazy about the individual cell voltages bouncing around all over the place on my home system (4P16S 800AH). plus, the...

I wanted to post a positive experience regarding Bestgo batteries, from China. The one I have is a 400Ah 12V battery for an RV, which I bought after many detailed conversations with Tony of Bestgo to allay the suspicions I developed after my experience on Alibaba. I finished capacity testing a...

Didn't want to start a new thread so I'll post here and see if anybody can help. If not, I'll start a thread on this. I have 3 EG4 indoor wallmounts on the way and I am trying to be prepared since I will not have power during the transition to these EG4s. They will be standalone as my Magnum...

I might be missing something but if you put the three cells in parallel to do the top balance, shouldn't that prevent "runaway" of any cell? The times I've witnessed overcharging from runaway is in series.

thank you, that helps. do you think the thinner separator results in higher risk of internal shorting? presumably they've worked it all out and it's just fine but the paranoid in me is just trying to reconcile this apparently significant difference in power density.

Alrighty then, can you tell me what circuit the small blade fuse that inserts into the bottom edge of the controller protects? Is it the battery or solar or load? My larger Victron controllers don't have a fuse there.

Thanks, I hope you're correct because that will provide a handy disconnect for the solar in case I need to do anything. Maybe Ben will clarify as well.

nix this, i just remembered that the chargery would operate the contactors on individual cells going out of range so the voltage inaccuracy would make it unreliable.

sounding like a winner to me. is there any info about whether the clamping is needed in low charge/discharge usage; is the swelling that occurs only likely during high charge situations or is clamping beneficial to retain shape no matter how "hard" the cells are used?

Another poster just sent me your link. I am in the middle of the exact same experience with Huanhuan Energy and Alibaba, except that I bought 64 of them! Mine are testing at an average of 165Ah (3.65V to 2.6V cutoff). There are others who are indentifying much the same situation. The serial...

Sorry to hear about another one. where, when, and from whom did you purchase these?

if you're watching this thread, would you please clarify what limits discharge on these. assuming standalone configuration paralleled to each other but no other communication charge regulated by external controller discharge limited by low V setting on inverter Will the internal EG4 bms shut...

I just replied to you earlier comment where you were first identifying this issue. I have the same issue with 64 cells from Huanhuan Energy/Alibaba and I propose we start assembling all those with the same issue and proceed along legal lines and by contacting the international trade authorities...

I had exactly the same experience with Huahhuan Energy. I was referred to them and was comforted by their high ratings but they also sold me 200Ah cells that test out at around 170Ah. I didn't find out soon enough to get any $$ back from CITI or from Alibaba and Huanhuan Energy is denying all...

if you haven't already purchased, you may be interested in my experience: https://diysolarforum.com/posts/174974/ and, i am now hearing from others who purchased from huanhuan energy and have received cells that are under capacity and don't appear to have legitimate CALB labels.

I am trying to find out if it's advisable to install a Class-T fuse between the EG4 wallmount 14.3 kWh batteries and the inverter? I believe their internal BMS is supposed to limit current and then there's the breaker/switch as well but is that enough or should I add a T-Class to deal with...

Just thought I'd summarize and report back on my experience with Huanhuan Energy. I bought 64 "200Ah" cells from them on November 30th, 2019 and received on January 6th, 2020. Not until a premature low voltage shutdown in October did I suspect they were under capacity because usually they are...

thank you for correcting this, my apologies!

I appreciate your posting this. I bought cells from Huanhuan Energy off Alibaba and this is a picture of the labels on them: The cells were sold as new 200Ah but they are testing at about 165Ah. Is huanhuan energy a legitimate vendor of CALB batteries? Does this label appear legitimate to...

will prowse replied on his utube post that he has tested them and they were fine. I'm glad to get this verified.

I didn't see the name of the vendor, would mind sharing it? also, do CALB batteries always have the Chinese sympbols embossed in the casing?

I love the internet and I love you, man! That's great to hear. I need to learn how to update the firmware and install battery monitoring software but I have a few days to do that. Thanks again!

It pays to be a packrat, I think I have both cables and am attaching pix. With the instructions I found and your recent explanation, I think I can try it although maybe it's not necessary to do immediately?

Right now, the only low cutoff I have is my inverter and the highest low cutoff it offers is 48.8V (3.05V cell) which is what triggered. There's a small V difference between the inverter and reality though and I noted that the cell voltage was actually 3.065V at the lowest and very consistent...

very helpful, thank you!

So, this fuse doesn't negate the need for a separate fuse on both the solar feed and the battery connection?

This is the URL: https://eg4electronics.com/resources/downloads/ This is a high quality RS232-USB so unless something specific/different is required by EG4, I figured it should work. Vendor is Portable-Sun who was great, included two paralleling kits, shipping, no tax with discount came to...

sorry, i posted by accident, fat thumbs. i appreciate your helpful reply. my hope was (and still is) that will prowse or either of the other two guys with teardown vids may have run a capacity test as well. it seems like it's a reasonable thing to do.

But, if it "protects from over amping" that's exactly what I'd be putting an in-line fuse to do, right? Maybe it's simply a reverse polarity protect? Plus, John frum indicated earlier that this fuse interrupts the solar side. Oh well, I ordered yesterday and guess I'll need to do some testing...

they say 7" between them for indoor and 12" for outdoor when they're side-by-side. they don't have clearances if front to back but i doubt they should be right up against each othet. what spacing are you thinking because i may try that arrangement as well?

Thanks Mike, I had already ordered these from Amazon when I saw you had posted: https://www.amazon.com/gp/product/B072QXDZRD/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 Seems like they should work and the cost is low if it doesn't pan out. Says they use 154 mA which should be low enough...

sorry i have not been clear on my testing ijn this post. i think the confusion is i have talked about two capacity tests - the first, unintentional one where my low voltage cutoff was triggered, and the tests i am doing now. these tests involved removing one set of 4 cells at a time, leaving 15...

I agree that you've solved it. The battery manufacturers are in a difficult spot because of the wide range of charge rates that are used, especially in RVs. When they spec 14.4 or 14.6V it's totally reasonable for a high charge rate but using that at low (typical solar) charge rates will...

did you end up buying one of these? i am curious if they deliver the capacity they advertise.

Does this label look like a legit CALB 200Ah cell? The first characters on all of them are P8215 which makes me wonder if they were supposed to be 215Ah when new.

Hey, did you come to any conclusions on BMS? I am in the same boat. Did you look into the Chargery and the Dalys as well?

Active, continuous balancers for 3.2V Lithium Iron Phosphate cells. I purchased from Electric Car Parts Company and used for a year before moving to a different system. They have LED lights that indicate when they are charging or discharging a cell. They are the same as ECPC is currently...

Yes, thanks. I've already reprogrammed solar charge controller and inverter/charger to match your recommended values. Your specs don't seem to quantify an absorb duration. I interpret that to mean your recommendation is that as soon as the battery attains absorb voltage it should drop down to...

Would you mind providing a reference to where EVE suggests clamping will increase cycle life?

I appreciate your input. I am voting for one or two above. it is possible my pack was not "fully" charged but all indications are that it was at least 95% based on slow charge rate (<0.05C), absorb at 3.45, and balance within 60mV at absorb voltages. Plus, when it shut down, at 650Ah and roughly...

I have been trying to find where EVE recommends clamping their cells and that doing so will increase their cycle life. I just downloaded the data sheet for the EVE 280 LFP and I don't see anything about clamping in there or differences in cycle life. Here it is...

thank you very much!

and i got ripped off by donguan huanhuan off aliexpress as well. they sent used batteries but i didn't have the ability to check capacity until a few months later and found they were 165Ah rather than the 200Ah advertised. they were a total ripoff. and, there were several people who said they...

This is an explanation about swelling I received from Tony, who heads up Bestgo batteries, thought others might find interesting: The "expansion" due to breathing effect is allowed,. The "swollen" due to H2O caused is not allowed. The "expansion" in breathing effect is due to lithium ion...

FWIW, I tried driving a standard 12V contactor with the 712 and could not get it to operate. The contactor requires just under 1A when it's engaged (I measured it at 0.95A), which the 712 should be able to drive since it's barely within its stated 1A spec. But, it may be that the surge current...

one quick clarification, i may be confused but wouldn't 1C discharge indicate "Full to empty" in one, not two hours?

Is the swelling caused by outgassing during charging and then the gas is normally resorbed during discharge? If so, it kind of explains why slow charge/discharge are less likely to cause swelling. Is this only (or at least mostly) only a factor with the newer thin aluminum casings vs the older...

I am glad you posted this because I was on the verge of springing for their $1K 200Ah LFP battery. I understand that it needs to shut off charging to protect a cell but, you're right, it should not shut down for more time than needed to rebalance the cells. That's concerning.

thanks for this, yes it is an active balancer in that it always is trying to keep the cells at the same voltage within the range that is set (i have it at 8 mV now). I do not have an active BMS so the only shutdown mode is through an inverter cutoff. however, the balancer has its own lower limit...

Hmmmm, I downloaded the firmware updater for this battery from the EG4 site and got all kinds of warnings about installing it on my PC. Is this normal? When I went to the Import HEX file button, the only option was in Chinese, which I am not completely fluent in! Is that the file that should be...

I have a query in to EG4, I'll post their response as I imagine others would like to arrange them more or less this way as well.

i think this is an excellent idea and i also have no idea how it could be set up. perghaps one of the moderators could weigh in here? Dongguan Huanhuan Energy's high ranking was crucial to my choice to buy from them and i thought removed a lot of the risk. i was so wrong. this is the worst deal...

I did purchase with a CITI card but because I didn't realize the undercapacity issue until 9 months later, they said it was too late to file a dispute. I didn't mean to imply that it's not possible to have good experiences with Alibaba. In fact, I have had good luck with AliExpress so far with...

there's also the chargery bms, which i have had mixed luck with.

I am new to this discussion and controversy. Was shopping a small Victron charge controller for a portable set up I am putting together for a van and stumbled upon Signature Solar who has a great price on the unit ($20 less, a little over 20% cheaper than Amazon). Googled looking for others'...

I assume I am simply misunderstanding something but I am confused how EVE 280Ah cells can be about 71% the volume of CALB or similar 200Ah cells yet provide 140% the capacity. The CALB 200Ah measures 279x182x71mm which works out to about 220.2 cu in. The Eve 280Ah measures 205x174x71.5 or about...

I'm wondering if SOC meter error is what I am seeing as well. My 3 wall mount batteries have been on line for a week or so and I have been trying to verify their capacity. I have a Victron BMV712 shunt battery monitor that measure the Ah used overnight. Based on the batteries' SOC in the early...

yeah, i was just pointing out that if the cells are already encased, they're probably ok in terms of adequate constraint against swelling. i looked for the EVE 105Ah data sheet last night but couldn't find it. i emailed EVE for it so i'll post it if/when i hear from them.

thanks snoobler, i wondered about the case thickness/weight. i forgot to post that the 200Ah weighs 5.7kG and the 280Ah weighs 5.22kG. i don't know the weight difference of the casings. if you assume the polymer is heavier than the aluminum, to me it seems unlikely it would be a pound heavier...

I recently bought 3 of these wall mount Power Pros that are supposed to have 280Ah, 14.3 kwh capcity. I am wondering if anyone has actually run a capacity test on these batteries to verify the stated claims? I have capacity testers and would like to do that but it's difficult because the BMS...

If this thread is still active, I'll second or third the use of 3.45V or so as a great target voltage. One difficulty is charge rate. If your rate is low (0.05C or so), then the cells are approaching full capacity as they get above 3.4V so hitting 3.45V and holding for a short absorb will get...

OMG Mike, thanks for sending that link but it was way over my head! I wouldn't know where to start to buy the right one.

that's great to know. i laughed about your parenthetical statement because that is exactly what happened, house/cat sitter who is a wonderful person but not in tune to living off grid in combo with an snow on panels and unusually long time without sun in normally sunny new mexico; literally the...

Would you be willing to share the results of your tests? I am very interested in seeing the temperature related differences for capacity. I've found generalized temp vs capacity curves but specific, real-world test data would be terrific.

for those of us in solar world, charging at 0.07C or less, 13.8V absorb is awfully close to 100% anyway. It doesn't surprise me that the balancer could not keep up when charging above 13.8V at low charge rate because one or more of the cells are in the near-vertical part of their charge curve.

Not sure if this is stiull being followed. I was (am) considering the Bestgo battery and noticed in the warranty that they only promise it will be at 80% of stated capacity in the first year and 70% by the 5th and final year of the warranty. So, it's not clear that this battery will actually...

not true, most batteries claim 1,500-3000 cycles but there is variability in what's reported because life cycles depend on depth of discharge and they're not standardized. i believe renogy's 2000 is based on 80% DOD which is way deeper than most of us typically go and you'd likely get many more...

Yeah, I did use Trade Assurance but didn't figure out the cells were under capcity until after the three month dispute period had passed. I did try anyway and was flushed by Alibaba. Thanks though.

I contacted them about that because it also says 200Ah in those specs. They are incorrect and will update, may have already.

I'm happy to trust the Victron. Do you think I can also trust the tested capacity info that was provided with my batteries? I'm not sure but I also thought the low-end cutoff for these batteries was triggered when the SOC hit 20%, which if it's off by much will mean effectively less capacity...

yes, i see the test reports but how can i verify that they're "reliable"? also, how do i view battery logs? i don't see anything like that in the very limited menu on the battery screen.

That's very similar to the approach I took at the beginning. I couldn't push the bank much above 3.4V (54.4 bank voltage) early on or I'd have some groups pass 3.45V and then runaway while others were not yet chargedm(hadn't reached 3.4V). Over time with the help of a 10A active balancer and by...