question

whafa avatar image
whafa asked

Best 48v BMS

Hi everyone,

I am expecting a shipment of 16x280Ah prismatic LiFePO4 cells. It is my first experience with non-lead acid batteries. I understand that I need a BMS, but there is incredible selection and profound difference in cost between models. I currently have a Cerbo GX which I understand has two data busses, a CAN bus and a proprietary VE.bus. This paragraph is the entire sum of my BMS knowledge, +/-.


I want to find a BMS that integrates maximally with the Cerbo. I'm happy to pay for quality. I don't necessarily need it to be a "supported" solution by Victron, as long as it integrates well. In another group on DIY Powerwalls, Batrium seems to be the most popular name in BMS. Is anyone running a similar system to what I've described, with a Batrium BMS?


What other options do I have? I'm also impressed with REC-BMS, but it's very pricey. A couple other ones I've glanced at are 123Smart BMS, Tiny BMS, Chargery BMS and DIY BMS. Also Daly?


The two most important things to me are 1) safety and 2) integration with my Victron products. This will be a 16s, 48v (although it's not a strict design requirement) LiFePO4 battery with low-moderate current requirements (probably something like a 3000 watt inverter). Thanks for any input!

cerbo gxLithium BatteryBMSVE.BusVE.Can
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16 Answers
nebulight avatar image
nebulight answered ·

You say you are happy to pay for quality, but in the next paragraph you state you are impressed with REC but it's very pricey. The maximum integration with Victron is going to be REC. Batrium does work as well, but I don't have any experience with using it. However if you think REC is expensive, Batrium is even more.

While it's not officially supported by Victron, REC makes sure their BMS communicates with Victron gear. You do get what you pay for with REC. With that said, how do you plan on using this system? Will it have DC loads? Their 16s configuration doesn't support disabling external loads (like DC loads) so you have to keep that in mind. If the battery is fully discharged by a DC load (that the BMS can't control) then it will disconnect the main contactor which basically turns off the battery.

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whafa avatar image whafa commented ·

Thank you for the reply. It's true, I am a bit shocked at the higher end prices of BMS. But I am making a substantial investment in my battery, and the raw cells were (relatively) cheap considering their capacity, so it will be worth it to find something that will coddle those cells.


The system is ultimately intended as a (probably) off-grid replacement to a utility line coming into my shed, which powers a standard fridge, freezer, washer and dryer, lights and tool chargers. Farther down the line, I'd like to integrate it to my house panel for emergency backup power. I live in a very mild climate with zero AC needs and gas for heat.

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Meine_Energiewende avatar image
Meine_Energiewende answered ·

Batrium works quite well with my victron system and my lifepo4 cells. But it is quite expensive too. It integrated fully into the cerbo and victron environment.

Jens

4 comments
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Juraj Nikolov avatar image Juraj Nikolov commented ·

Can GX handle more than one Batrium BMS ??? for example 3 pcs ???

Thanks


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nickdb avatar image nickdb ♦♦ Juraj Nikolov commented ·
The GX will only use one. So if the BMS isn’t capable of master/slave configs it will just ignore the rest.
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marekp avatar image marekp nickdb ♦♦ commented ·

REC BMS has that option

https://www.rec-bms.com/rec-bms-master-unit-9m/


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autox avatar image autox commented ·
Hi jens,


Not knowing how to reach you differently, so hoping you will answer here.

You have a lot of batteries and batrium.

So you connected these batriums by can to each other and the main controller on the wall.

Can you link some resource so I can read or watch how this was done exactly?

Currently using jkbms and cerbo does only support 1 master bms.

As per my opinion, I want to have central bms managing all cells and telling cerbo when to throttle the speed of charging.


If you would able to help it us highly appreciated.

Thanks

Chris




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tristan-klatt avatar image
tristan-klatt answered ·

Hi whafa,

i had tested a lot of BMS´in the last years, but not Batrium or REC - both are very expensive and i tried to find a solution that works, but for a "diy"-price.

To describe all the other BMS i tested woud be too much for this forum, but i can give you a good recommendation for the following sources:

On youtube look for the channels "offgrid garage" by Andy from Australia - he did a lot of tests too and has links on his hp to inexpensive sources on aliexpress. Especially look for the Hankzor BMS. I will install this in my next project too. Second channel on youtube ist "Meine Energiewende", a german guy, very familiar with Victron products an also with the Hankzor BMS. On https://www.youtube.com/shorts/fw_fJFkhnX0 he shows the wiring for this BMS with a Victron installation and it works fine.

Nevertheless is it a lot of work to read, listen and understand all the backgrounds, to install this combination yourself, but if you understand your system, it´s much more fun and a lot of money you can save.


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David avatar image David commented ·
Andy doesn’t use any BMS that communicates with the Victron. There is no can bus comms at all. The batteries are basically stand alone.
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jeanmarie avatar image
jeanmarie answered ·

Hi @Whafa

don't know the price range you are talking about for mentioned products but I can testify that Seplos BMS are working well within the victron environment (I have 6 of them chained and with one BMS CAN link)

The only disadvantage I found up to now is that the RS485 link (allowing you to see / program the BMS datas) is not compatible with BMS CAN, which means you must disable the BMS CAN communication for the time being you need to send new configuration to the BMS, fortunately this is not really common.


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leighc avatar image
leighc answered ·

Tao make a good BMS, but you need a master (12v base system) & 3 slaves (extensions)

They integrate with Victron via CANbus & have Dynamic 4amp cell balancing, There is a comparison sheet on the Website

TAO Performance ‣ Lithium Battery & Energy Management System

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Paul B avatar image
Paul B answered ·

The ones I have used are TAO and 123 smart BMS, the best priced one is 123Smart BMS, it also has a FULL interface to the Cerbo being a USB connection unit. we have installed over 100 sets of these ourselves and they have proformed VERY well, you can also connect by Bluetooth, and there support is excellent.

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Paul B avatar image Paul B commented ·
Of note they are Passive balancing - TAO is active balancing.
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Ants Kosmos avatar image Ants Kosmos commented ·

How long this bms balanced cells ? I have 304ah 16s but 2 hours is too short time. Charging voltage is 54.8V Multiplus 2.

1704442081622.png

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klim8skeptic avatar image klim8skeptic ♦ Ants Kosmos commented ·

@Ants Kosmos 60 or 70mV difference between cells is not enough to worry about.

Charging your cells to an average of 3.425v is a bit low.

Have a look through Andy's videos plenty of useful info.

What is the balance current of the Smart123?



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Ants Kosmos avatar image Ants Kosmos klim8skeptic ♦ commented ·
Factory says 1A. I look Andy video too. 123Smart bms communicate with Venus on and set charging voltage ? I set 55.2V on Multiplus 2.
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marekp avatar image marekp Ants Kosmos commented ·

@Ants Kosmos

I would suggest to confirm the values reported by 123SmartBMS with proper voltmeter.

My 123SmarBMS is sometimes reporting inaccurate values.

img-1115.png

Cell #14 is a extreme example because in reality has 3.35V (measured by voltmeter) and not 3.32V.

Same with all other cells voltmeter shows almost identical voltages but 123SmartBMS shows those differences as seen on the picture.

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img-1115.png (282.8 KiB)
Ants Kosmos avatar image Ants Kosmos marekp commented ·
When all cells charged to 3.4v then bms set soc to 100%. When charging voltage is 55.2V, i never see some battery pack soc 100%. Maybe this help if i switch on bms critical mode ?
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gero avatar image
gero answered ·

I even can not understand why Victron is not willing to make the system more open for other DIY BMS systems, like JK Hankzor, Daly, LLT which are in a very good price level and more technically up to date than REC and other BMS Systems for 500-1000 €. The supported BMS are working with passive balancing, mechanical contactors etc. vs. Hankzor / Daly which are working with modern MOS,they can select between switchen charge and discharge current, have active balancing funktions and Smart APPs working out of the box. For those BMS it is necesary to use third parts drivers and hours of trail and errors as well a study at Youtube-University. Due that Victron devices are also produced in China, it would be a easiness for their chinese engineers to make it compatible for the chinese BMS stuff.


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Craig Myatt avatar image
Craig Myatt answered ·

I have just setup a 48V lithium battery (16s) with a batrium BMS. This was actually originally a proprietary lithium battery from another maker, where I removed its BMS so I could use the cells, and discard the inverter part, to use with a Victron system. Works well with the cerbo/victron system but ...Batrium however is difficult to get into, their documentation is while fairly complete, also disordered.

I am trying to find an alternative which works like a GenZ battery: ie a self managed lithium battery which simply takes a charge like a dumb lead acid battery, and will not exercise direct control over the MPPT charging, or the Multiplus when the voltage gets lowish, like 51.5v. (At this relatively high voltage, the MPII starts to switch off, because of 'low battery voltage', clearly a problem.) Anyway...I am about to go a do a quick review of the following BMSs, some mentioned here:

  • Batrium as non-canbus
  • Orion
  • Chargery
  • 123Smart BMS
  • Tiny BMS
  • DIY BMS
  • Daly
  • REC
  • Hankzor
  • Seplos
  • Tao
  • Electrodacus


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sean avatar image sean commented ·
Both the REC and Batrium documentation are aimed at competent, qualified and experienced people and not those with little knowledge expecting to be walked through every step of the configuration process.
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puitl avatar image
puitl answered ·

Don´t forget this "problem":
https://community.victronenergy.com/questions/106290/bug-in-ess-dc-feed-in-enabled-charge-current-limit.html?childToView=181085#comment-181085

> Conclusion: The BMS has to reduce the CVL when a single cell-voltage is getting too high!

Only REC and Batrium are doing this what I know (with latest Firmware allegedly also the Seplos).

With other BMS (which only reduce the CCL) you have to implement it yourself or you have to take perfect matched cells, a strong balancer and a max. CVL of 3,55V (per cell, to have some reserve)

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Paul B avatar image Paul B commented ·
123smart also controls via CVL when a single cell is getting to high as well, I have found there BMS to be very good and there manual and support is excellent, its also got a LOT of nice extra features that can be turned on and off via the Bluetooth app and the victron interface works well, it also has a victron driver installation service when using GuiMods as well and thus save a lot of time and hassels in the setup.
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djdemond avatar image
djdemond answered ·

I will add my experience to this list. I have three systems running Daly 250 amp SmartBMS with 460Ah 16S LiFePO4 batteries. It can manage 0.2 amp balancing by default. Daly make an active balancer module you can add for around 1-2 amps balance. Using this enables control of balancing via the app/PC software.

I am using 3rd party 16S 5A active balancers in parallel to the BMS instead, seemed simpler and more effective and it has been so far.

The setup was easy just check and connect the balancing cables, the BMS turns on. You can use a Bluetooth UART addon which just plugs into the UART port and an app. However, it's better to opt to have the UART to RS485 cable supplied by Daly and connect it instead to a PC. Now you get more data and some software which can upgrade the firmware etc.

My systems run a maximum of 70 amps on the DC, so the BMS is over-specified. However, it does not get hot and the fan never turns on.

If the cells get out of balance the BMS will show a low pack voltage to the inverter which will back off or shut down. I have attempted recently to connect this BMS to a Multiplus II via CAN in order that it can act as the battery monitor instead of the MP2, but have not yet had any success. There is a thread about it here

https://community.victronenergy.com/questions/178547/multiplus-ii-connection-with-daly-bms-daly-interfa.html?childToView=193995#answer-193995

If I manage to get it working I will post my solution on that thread.

I have no doubt that some more expensive BMS solutions can do better and with more finesse. However, for around £100/$120 it seems to be working extremely well. It has never done anything odd or unpredictable and I do not doubt it's ability to protect my cells.

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ron-h avatar image
ron-h answered ·

The new JK BMS seems to be ok.

https://off-grid-garage.com/battery-management-systems-bms/

With latest firmware full integration with Victron.
I did order one for mine new to build 3 phase system.

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cocodanila avatar image
cocodanila answered ·

Latest JK BMS seems to be the best answer to your problem, has integrated equalizer as well. Although the product start looking ok, and progress quite fast in the last 4 month, it is still a work in progress. But even so, I would trade GLADDLY my Seplos 10E for an JK BMS for the functionality has inside!!

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cocodanila avatar image
cocodanila answered ·

As I mention, it is still a work in progress. The community of Andy s Garage just found it out about a major error in the new JK BMS ; you should NOT USE thsi device at the moment!!

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ron-h avatar image
ron-h answered ·

I just wrote JK if I should directly return the BMS (still in shipping process to me) or how they planning to fix this issue.

How a faulty BMS can be recognized, and if the issue will be fixed in a new firmware or a hardware change has to be made.

As soon the developers do have a solution I will get a message from them.

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cocodanila avatar image cocodanila commented ·

I am guessing will be in shipping for a while, seems that they runn out (or stop shipping it) they start selling it at the discounted price, and so....I would suggest to cancel order and ask for a refund. Andy was really pissed, I am really annoyed about how could such a simple mistake with such a huge impact got unnoticed in their "testing" process. I am guessing software developers will react fast, but now, can you trust them?

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ron-h avatar image
ron-h answered ·

Seems the parameters are stored in ram memory only, they should save them in flash memory.
Think next firmware version will fix the issue.

But your correct what will be the next bug, can you trust this BMS,…?

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ron-h avatar image
ron-h answered ·

Just got a mail from JK
They will send me the latest V14.17 firmware to fix the problem.

See off grid garage already uploaded it.

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