BMS china vs Batrium

Earlonics

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Hi All another newbie question :)

I see Batrium seems to be the choice of many for balancing their packs, but that does come at a price, and appears the Rolls Royce of BMS's

I have recently seen a video by "DIY Solar Power withWill Prowse"


This isa BMS offering from HK/China seems from the Video very cheap, has also low and upper temp control andlooks like it can match the job of a Batrium at a fraction of the cost, (I would love a Batrium but at the moment cost prohibitive for me).

Has anyone any experience of this device? I was looking atbuilding the BMSDIYv4 but Will's solution looks like it could save me loads of build time.

I've taken a punt and order one, its not going to arrive until mid January, if anyone else is interested here'sthe link.

https://www.ebay.co.uk/itm/Smart-Li...var=493362285172&_trksid=p2057872.m2749.l2649

When it arrives I'll try it out and post my findings in the mean time if anyone has any experience of this device I would love to hear.

I understand that the main battery leads will probablyneed to be upgrading

Cheers

Paul
 

daromer

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No it cannot match Batrium

Its like with everything else that for most gear the price defines what you get in the end. A cheaper BMS will work to some extent as said. And you choose the Gear based on your goal and what you can afford compare to what you need.

Its cheap for a reason and if you start to look at what Batrium can do and how accurate it can do you you quickly see whats going on between them.

I have tested many BMS systems during the year but for my main powerbank Batrium just works and I have not touched my main battery bank for 2 years now...
 

OffGridInTheCity

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Agree with @Daromer 100%.

One example (but by no means the only example)of what Batrium does for me is 'ongoing info'... which I record. This is critical for my strategy to detect/repairfailing packs and to provide clear insight into what's happening.

I think that one aspect of this cheap vs expensive discussion is short-term vs long-term. For the short-term, sure a cheaper BMS may be completely adequate protection.For the long term... and/or larger power production...the decision becomes clearer over time.
 

Earlonics

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Thanks offthegrid and daromer, appreciate your reply's, its obvious this journey is not necessarily going to be cheap.

I fully understand the risks of using such high density storage devices so its key to air on the safe side especially dealing with Balancers. Did you folk start off with a Batrium or did you start of with something more basic first?
I've quickly discovered by the time you've purchased your batteries, solar panels, inverter and BMS the money soon mounts up.
 

daromer

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Yeap its not cheap. If you think Batrium is expensive i can say that batrium was 3% of my battery cost and just 1% of my total cost :D


For a small 1kwh battery bank i would agree that Batrium is way over the top expensive comparing and for such a system a cheaper BMS might just be the best choice.

It is what makes "you" feel secure over the installation that you basically pay for. But at same time just getting the gear does not make it safe unless its set up correctly and you know how to work with it.

Many people havent even tested critical fault and have no idea how it works. Then they come back weeks later complaining "The BMS didnt work"..... In most cases user-errors.
 

not2bme

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As you know the board members here are heavy with batrium. But there are a few of us that do use chinese bms and have achieved a level of success. The most important thing for a bms is to be able to report and trigger a cutoff when necessary. The other aspect is to balance the packs. I managed to take the output from my active balancer and log the output into the influxdb database. At this point I am still fascinated and watch this data over grafana daily. So I do know just as much as a batrium system would report and I would not even think a batrium system would do any better. Some members here think a batrium is the only answer and that it is money worth spent, but I disagree, since it's still a diy effort and if you're willing to work on it, then its worth it. Otherwise why bother building a DIY powerwall at all? Just buy a Tesla powerwall and you have all of the above, all supported, with warranties, etc.


image_oqhzta.jpg
 

gpn

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not2bme said:
As you know the board members here are heavy with batrium. But there are a few of us that do use chinese bms and have achieved a level of success. The most important thing for a bms is to be able to report and trigger a cutoff when necessary. The other aspect is to balance the packs. I managed to take the output from my active balancer and log the output into the influxdb database. At this point I am still fascinated and watch this data over grafana daily. So I do know just as much as a batrium system would report and I would not even think a batrium system would do any better. Some members here think a batrium is the only answer and that it is money worth spent, but I disagree, since it's still a diy effort and if you're willing to work on it, then its worth it. Otherwise why bother building a DIY powerwall at all? Just buy a Tesla powerwall and you have all of the above, all supported, with warranties, etc.


image_oqhzta.jpg

Not sure if I missed a build thread. If I did please link it! I'd love to see a thread on how you got that all to work. Which hardware and whatnot. That would be awesome to setup.
 

jonyjoe505

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For balancing a pack, especially if the pack has balance issues, active balancers work best. The bms in your link only balances at 100ma, if you plan to fast charge your pack at high amps, the 100ma might not keep up with that.

If you plan to charge your lithium with solar, a bms that uses external contactors to stop the charge is recommended. If the bms uses mosfets to stop the charge you will get power surges from the charge controller.

I been using the chargery bms8 as my bms on my 4s 220ah lifepo4 which is charged by a 240 watt panel/20 amp mppt. The chargery cost me 86 dollars and uses external contactors ( I use 4 dollar 30 amp automotive relays) . This bms also balances at 1.2 amps per cell. It has a nice bright lcd where it shows each cells voltage.

I used almost a year and has been perfect, it just works. All the other bms I use gave me voltage surgeswhen they triggered. No more voltage surges. If you will be charging with solar and your new bms gives you voltage surges, get a bms withcontactors.
 

ajw22

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not2bme said:
As you know the board members here are heavy with batrium. But there are a few of us that do use chinese bms and have achieved a level of success. The most important thing for a bms is to be able to report and trigger a cutoff when necessary. The other aspect is to balance the packs. I managed to take the output from my active balancer and log the output into the influxdb database. At this point I am still fascinated and watch this data over grafana daily. So I do know just as much as a batrium system would report and I would not even think a batrium system would do any better. Some members here think a batrium is the only answer and that it is money worth spent, but I disagree, since it's still a diy effort and if you're willing to work on it, then its worth it. Otherwise why bother building a DIY powerwall at all? Just buy a Tesla powerwall and you have all of the above, all supported, with warranties, etc.

Can't agree more, including being addicted to watching the Grafana stats ;-)
Those Chinese BMSs are more aimed towards ebikes and such, so they only provide Bluetooth (ie short range) Apps for viewing stats. Requires some programming knowledge to make the data available via WiFi/LAN/Internet.
Also the balancing current may be inadequate for larger powerwall batteries. It'll depend on the quality of your cells, but I'd say 10kWh is about the max, at which point you should consider using 2 batteries with one BMS each.
Have a look at my powerwall.I currently use 4x similar BMSs in parallel.
 

not2bme

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gpn said:
Not sure if I missed a build thread. If I did please link it! I'd love to see a thread on how you got that all to work. Which hardware and whatnot. That would be awesome to setup.

Here is the link
https://secondlifestorage.com/showthread.php?tid=4229&pid=35023#pid35023

I have to say the balancer I'm using right now isn't the best. It balances but with no adjustable parameters. So I can't trigger it to activate at certain voltages, etc. It just balances to 40mv. Other than that it functions. What it had was it uses a TTL serial output to a LCD screen to display the current voltages. I knew I could take that serial output and bring it into the raspberry. From there that's where the magic happens, using python, it takes the output from the LCD, then I parse the output through it and input it into influxdb. Don't need to have any real programming skills but I've learned enough through the years and it's really the basic stuff, taking a string of characters like 'Temp: 10.0c' and extract just the 10.0 part of it. Grafana is currently alerting me when voltages and temp are reaching critical values, while when reaching critical values I can fire off relays to cut the battery.

The bms from the original poster is what I believe ajw22 is using and there's quite a few posts on communicating through bluetooth on that unit already. I would check his setup out.

I'm working on another active balancer that has programmability and bluetooth communication. I think this one is worth exploring and if I do get it to work I will post up a build thread just on it. My goal is to have an under $100 bms that is good enough, combined with a raspberry pi, able to fire off a few relays and sense a few temp using a 1-wire sensors.
This is the balancer.
https://www.aliexpress.com/item/32945565819.html
 

Headrc

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Other BMS units by Rec and Orion also seem to be robust solutions and have good reputations even though Batrium seems to be the favored one for whole house systems on this forum. Batrium will also add even more expense if you have any support needs from them. As per information I received from Maxine recently at Batrium, after the first 30 minutes of support time from Batrium there will be a charge for any additional support after the initial purchase. But as indicated on this forum, Batrium is a very powerful solution and there is a lot of tutorial information provided on this forum for it. Tutorial information like that for the Orion and Rec systems is not available on this forum but in my dialog with both of those companies they seem ready to help at any time with no additional charge for that service.
 

OffGridInTheCity

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My focus is whole house power production / larger battery banks. My battery bank is approaching 70 260ah packs. So I'm writing this with 'larger power wall' thinking in mind.

Rather than argue Batrium (which I like for my own situation) let me add to this discussion in a positive way bydrawing your attention to somenon-Batrium solutions that I find interesting.

In particular @DavidPoz did a Chevy battery system and wired the battery into 6 seperate 48v batteries - each one had its own cheap BMS with bluetooth. Here's a key youtube (he did several if you care to see the overall build-up) - "DIY Smart Fortwo Battery build, Finale!"
The 6 separate were paralleled into a set of6 circuit breakers at the overall +/- terminals (see 13:53 for a visual). He accessed the 6 BMSs via bluetooth on his phone (see 14:44 and following for some visuals on this).

The lesson from this - its the first design I've seen where there were multiple 'cheap BMSs' parallized into what I would call a powerwall size battery bank. To me, this is a soliddesign but I don't see myselfmanaging (flipping thru) the 6 separate BMS interfaces.

In his latest work he's using a cheaper active balancer? "Cheap Active Cell Balancer Test (Fail)" -https://youtu.be/9Q_s-rx5bKs which looks interesting but he hasn't revealed (or its not clear to me) the overall BMS (overvoltage cut-off).. unless its the one in the youtube.

-------------------
For me, the #1 thing I want from all my components - charge controller, BMS, inverters, is metering and record logs that I can retrieve, parse, put into my own database and use to inform on history and take action. Its amazing how difficult this is and how unimportant it is in the product listings - including Batrium.

Batrium has WiFi / PC capabilitiesandI found that it writes a status files every X minutes which I can parse. Phone/bluetooth don't work for me. @Daromer has documented a method to query Batrium info 'live' and I notice that @LithiumSolar uses this also... but frankly its technically challenging for me.

@not2bme shows 'data' from chap BMS buthave no idea how to even get started reading them. IF there were a way to do PC based monitor/reading dataand perhaps do a @DavidPoz 'combined' cheap bms soltuion then I think this would have worked for me as an alternative to Batrium.
 

daromer

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Batrium sends data up to every 150ms. Should be live enough for most users :) And its not hard to work with. its just to run the application and set the path to your mqtt or influx db and it fetches all data per default.


Im working on an easier setup for Solar monitoring. It will be based on docker and everyone can easy chime in on the different type of system. Instead of my old rather static solar-pi image :)

I have 2 more BMS systems i intend to incorporate there by default and one of them is the cheaper bluetooth and the other a red variant of the actibe balancing bms.
Its just a matter of time :D
 

Earlonics

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Thanks for everyone's input..a good selection of interesting comments .

It's clear everyone has individual needs and preferences. Just for information I've also been looking at Stuart Pittaway's solution found here https://github.com/stuartpittaway/diyBMSv4 this seems to have been thoroughly thought through, electronics doesn't phase me so seems an ideal potential solution for me especially around the costs.
 

OffGridInTheCity

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Earlonics said:
Thanks for everyone's input..a good selection of interesting comments .

It's clear everyone has individual needs and preferences. Just for information I've also been looking at Stuart Pittaway's solution found here https://github.com/stuartpittaway/diyBMSv4 this seems to have been thoroughly thought through, electronics doesn't phase me so seems an ideal potential solution for me especially around the costs.
There a youtube @Adam Welch that went down this road (I believe). He has several youtubes - here's a recap one "A year with the diyBMS" -https://youtu.be/DKz48WeSGlU
This one did not strike me as a 'larger scale' level (e.g. 70 packs of 260ah each) BMS - but it did include data capture and looked interesting for someone that likes building their own boards/circuitsand Adam did quitea few youtubes on his implementation as a guide.
 

not2bme

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OffGridInTheCity said:
@not2bme shows 'data' from chap BMS buthave no idea how to even get started reading them. IF there were a way to do PC based monitor/reading dataand perhaps do a @DavidPoz 'combined' cheap bms soltuion then I think this would have worked for me as an alternative to Batrium.

I actually have been reading all the data from my current BMS logged into influxdb. Have been for over 2 years! It's why I have the grafana display. Same with the original poster's board, which is based off a generic bms and the protocol has been documented and folks have put them in a database and queried with grafana. I believe ajw22 has done this to his setup since I've seen him with a grafana interface.


Earlonics said:
Thanks for everyone's input..a good selection of interesting comments .

It's clear everyone has individual needs and preferences. Just for information I've also been looking at Stuart Pittaway's solution found here https://github.com/stuartpittaway/diyBMSv4 this seems to have been thoroughly thought through, electronics doesn't phase me so seems an ideal potential solution for me especially around the costs.

Been a while since I looked at it but I like Stuart Pittway's v4 design, almost is Batrium-like. Built-in export to influxdb is nice too! Anyone figured out the cost involved? Pretty awesome project of him to release it to the public!
 

Earlonics

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Stuarts Github link includes everything including the gbr files for PCB production.

I've up loaded the files and placed an ordered for the PCB boards online at https://jlcpcb.com/ 20 boards worked out 30 delivered, just the parts which I believe is under 50.00, now I await in anticipation, then its just the time and effort to build them, so I await delivery and keep you all posted.
 

daromer

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Then you are very very very limited. Most higher quality BMS systems have windows applications what I have seen.

Note that you only need windows to set things in batrium. You can read all from any system you like. I use a Windows 10 tablet currently for configuring all things here. For your case the WM5 could be doable since its small and compact. With a 1000A shunt and a proper larger contactor you are set. I guess it will end at about 800-10000EUR in that range if you include all gear needed to your spec.
 
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