123 Smart BMS

[Ian]

Not much more news yet. I installed the bms and I haven’t had any issues with the Bluetooth yet. My battery was perfectly balanced before I hooked it up and it has stayed that way so far. I haven’t hooked up to all the relays yet. I’ve only hooked it up to my inverter charger and that seems to work well so far. Honestly though I wish I would have shelled out more money for a nicer bms. It’s silly that you have to solder the negative leads to the board. Also, for what you get in the kit it seems like they should charge less than they do.

 

[123Sebastiaan]

Hi!

Just came across this forum and saw this topic. I'm one of the 123\SmartBMS engineers.

Ian, what do expect the SmartBMS to have which it currently does not have?
The soldering can be made easier, we have this since the first generation and when gen3 was finished and in production, we thought: maybe it was easier to add a connector instead of a soldering pad. We are currently testing if we can swap the minus pad with a reliable (very important!) connector which fits in the space that is left on the board.

The price is based on multiple factors: the 2x dual range currents sensors are quite expensive (much more expensive than a shunt is), but have some benefits over shunts. One of them is that the sensors are isolated and when drawing larger currents, a shunt would dissipate a lot more power: at 500A each shunt would consume about 25W while the current sensor only does several mWs. Other costs are in the development of the app (app developers are quite expensive), Bluetooth module with good signal strength, using the Bluetooth name etc.

About the minimum temperature setting: we want to keep the SmartBMS as simple as possible. More settings means more time to configure and more possible mistakes when configuring. Most customers set the minimum temperature to values like -10 degrees celcius. A low temperature will also affect the cell voltage, so Vmin and Vmax are much more important. For example if you discharge with too large currents at low temperatures, the cell voltage will automatically drop below Vmin and the BMS will cut off. Of course the maximum temperature (Tmax) IS important, because this can prevent thermal runaway (smoke, fire etc).

Even though the settings look quite simple, there are some quite advanced algorithms in the BMS to determine battery parameters.

Because I will not read the forum frequently, it is the best to send feature requests/feedback to info@123electric.eu

Sebastiaan - 123electric

 

[CliveS]

Most customers set the minimum temperature to values like -10 degrees celcius.
Sebastiaan - 123electric

Which is as useful as a chocolate teapot, I would like to set my temp cutoff at 2c and stop discharging before I got to 0c and also have the charge relay still active so the battery can charge back up.

I can see why most customers set it at -10c, because it might as well not be their at all.

The only answer 123 have is to (over)charge for an add on relay unit with 4 more programmable relays and a lot of other extras that are not required that costs the same price as the SmartBMS.

Perhaps if you sold a 4 relay add-on unit for 50 Euros it would be a good idea.

CliveS

 

[123Sebastiaan]

Hi Clive,

Do you mean that you want to stop charging at about 0 degrees celcius and keep discharging?
The minimum charge and discharge temperature depend on the cell chemistry (and specifications from manufacturer). When the discharge Tmin is different from charge Tmin, in general the charge Tmin is higher (for example 0 degrees celcius) than the discharge Tmin (-10 or -20 degrees).

The general Tmin in SmartBMS is mostly set to -10 because some LiFePO4 manufacturers specify -10 degrees for charging as minimum and customers do not expect to work below these temperatures. Some customers set it to 0 degrees if the manufacturer specifies this as minimum charge temperature and because they do not expect the battery to go below these temperatures in normal cases.

Besides, there is an overtemperature, undervoltage and overvoltage in the BMS for protection.

The Extended Module (with CAN bus, 4 configurable relays etc) was primarely designed for electric vehicle conversions and boats which need the data on a bus or display battery data on a digital CAN gauge.
If you want more options, you can also connect a Raspberry Pi or Arduino to the BMS (you only need to add a simple isolation circuit, posted in the GWL blog) and then you can read out the BMS data bytes and control what you want.

You can send a feature request to our email address if you want something in the BMS which is not there yet, for example for the Tmin for charging and Tmin for discharging.

 

[CliveS]

Sebastiaan,

Hi Clive,

Do you mean that you want to stop charging at about 0 degrees celcius and keep discharging?

The exact opposite, I want to stop discharging at around 2c (hopefully I will not get there as I have a temp sensor start to warm the Winston cells at 6c via heat pads) but I would still want the charging to still be active if mains/solar was available. Last winter I saw the battery temp go to zero in my motorhome and the Votronic VBCS 60/40/430 was turned off by the BMS so could not charge the cells.

If you want more options, you can also connect a Raspberry Pi or Arduino to the BMS (you only need to add a simple isolation circuit, posted in the GWL blog) and then you can read out the BMS data bytes and control what you want.

You can send a feature request to our email address if you want something in the BMS which is not there yet, for example for the Tmin for charging and Tmin for discharging.

I was not aware of the Raspberry Pi option, I will look into that on the GWL blog but an option in the SmartBMS to split the Tmin for charge and discharge would make the SmartBMS a much better option for integration into motorhome/RV applications, which I doubt when it was designed you did not factor for, but now with more RV's having LifePo4 installed maybe you need to rethink this new market opportunity, this forum just shows the need for reliable BMS's.

CliveS

 

[Kwood]

I have the 123smartbms gen 3. The instructions suggest interconnecting the boards when attached to the cells. A slip with a wire can short out a board. Don't ask how I know that. I suggest interconnections be done prior to placing boards on the cells. Has anyone installed a Bluesea 7700 bistable relay with this BMS?

 

[Kwood]

Seeking opinion on the 123 smart bms gen 3

This BMS has 4 boards, one attached to each cell in a 4s config.

Voltage measurements are made by each individual board and are used for HVD, LVD and balancing.

The spec states +/- 20mv measurement accuracy.

In my case the between boards are measuring -30mv from actual. I've confirmed this and swapped cells around and the between board reading remain the same.

I would expect the tolerances to be better.

I can adjust the HVD and LVD to compensate for this, but balancing will consistently push the middle cells higher by 30mv.

Is this a problem?

 

[123Sebastiaan]

I was not aware of the Raspberry Pi option

Hi Clive,

I will discuss with the app developer to check how we are going to implement both Tmin for discharging and a separate one for charging.
You can find the UART isolation circuit and UART protocol here:

https://gwl-power.tumblr.com%2Fpost%2F173541225781

 

[123Sebastiaan]

In my case the between boards are measuring -30mv from actual. I've confirmed this and swapped cells around and the between board reading remain the same.

Hi Kwood,
Please email us at info@123electric.eu so we can help you. The offset should not be more than +-20mV. What multimeter do you use? It happens frequently that the multimeter also give a false offset. All cell boards are calibrated in the factory.

To be sure, I just took 10 Between boards from the last productions in our factory and compared it to my Fluke multimeter. They all had an offset of max +- 10mV.

Best regards,
Sebastiaan
123electric

 

[CliveS]

Hi Clive,
I will discuss with the app developer to check how we are going to implement both Tmin for discharging and a separate one for charging.

Thanks for taking this up as it would make a huge difference for the Motorhome/RV/Boat installs that are now becoming so popular.
Being able to control both the load and charge relays individually via Tmin1 and Tmin2 in the app would great, hopefully it would work with V2 boards as I have 2 of those.

You can find the UART isolation circuit and UART protocol here:

https://gwl-power.tumblr.com%2Fpost%2F173541225781

I think that is well over my head, just wish you could put out just a 4 relay board but I suspect it is economics that may be the problem.

CliveS

 

[Kwood]

Hi Kwood,
Please email us at info@123electric.eu so we can help you. The offset should not be more than +-20mV. What multimeter do you use? It happens frequently that the multimeter also give a false offset. All cell boards are calibrated in the factory.

To be sure, I just took 10 Between boards from the last productions in our factory and compared it to my Fluke multimeter. They all had an offset of max +- 10mV.

Best regards,
Sebastiaan
123electric

I have. Petr told me told me it is within spec.
I have two relatively inexpensive multimeters and a variable power supply - but they all agree. All cells are at 3.27v. The between boards say those cells are 3.24. I swapped the cell positions from 1 2 3 4 to 2 1 4 3 and the between boards still show 3.24. They are reading low by -30mv.

 

[Kingdaddy]

Could anyone share with us the super secret price for a 16cell 48v setup?

 

[Michael B Caro]

price for a 16cell 48v setup

for the entire set up, or just the cells, or what? Oh and, how many amp hours?

 

[Kingdaddy]

Too funny, I knew my question would be answered with a question, I gave enough information to get an answer!!. No one wants to just blurt out that it’s VERY expensive, kinda like buying a fancy car, if you have to ask how much, you probably can’t afford it. I did find a sight that quotes 123SmartBMS G3 4S, 2x I-sensor 2020 at 379 euros, that’s $449. So “my guess” is if I need it for a 16s 48v 280ah LiFePo4 battery bank, it’s going to run close or above $1000. Am I close?

 

[Michael B Caro]

Ok, so if you know you gave all of the information needed to get an answer, you obviously know enough to know what it is you need, so you could go find the answer for yourself. Not sure why you asked...was it just a test? All I saw was "price for a 16 cell 48v set up". No call to get rude or defensive

 

[ghostwriter66]

Sebastiaan,


The exact opposite, I want to stop discharging at around 2c

WHY would yopu want to STOP DISCHARGING at 2C ??? Our BMS that we use STOP CHARGING at 2C BUT we will DISCHARGE until it hits 7% regardless of the temp outside .. ITS CHARGING below freezing that kills the cells -- NOT DISCHARGING

 

[ghostwriter66]

About the minimum temperature setting: we want to keep the SmartBMS as simple as possible. More settings means more time to configure and more possible mistakes when configuring.

Sebastiaan - 123electric

I have not played with your BMS yet and if i have time will get one to do so ... BUT come on - engineer to engineer ... saying you only put a single temp setting in it to keep configuration simple is a little - well lame is the only word I can think of ...

We stop our charging at 2C and we discharge to 7% -- regardless of temp ...

 

[Kingdaddy]

Look mister, you’ve never posted here. Now you have twice, with unhelpful posts and false accusations of me being rude and defensive. So I’m thinking who is this guy, so I check out your history, read your posts. First of all, you claim you don’t know anything much about BMS’s. Hmm, then you go on to say that your “skill” is to identify the needs of the people, and help them fulfill there needs, oh so helpful you are. So I’m still giving you the benefit of the doubt and maybe you could steer me in the right direction, but alas, I find your “helpful” Group Buy Scheme you have been touting on other threads.
I don’t know who your buying your cells from, or how much your jackin the price up, but I know where I got my cells from, and they were
1. $110 cheaper for 16 than any of your quoted U.S. Zipcodes (so I saved more and purchased 32)
2. Covered under Alibaba.com Trade Assurance
3. My communication text strings for all the negotiations between seller and myself are documented, in MY name, not a 3rd party, so if problems arise, I won’t have to deal with YOU.
4. I have the seller telling ME, these are GRADE A, NEW CELLS, not what ever they told YOU
5. Paid directly with MY credit card and Its safety features and refund ability, without having to involve YOU.
6. Shipping time is the same, well, yet to be determined
7. Oh, did I say I PAID LESS.
If YOU wanted to be mr helpful, you would steer people to reputable sources, help them on how to communicate with the Chinese way of negotiating, and you would be better off making a few bucks to help pay for your own cells elsewhere. Maybe I should just start posting on your thread,.... I think I will, not bog up this one. I think it would be helpful

 

[Michael B Caro]

Look mister, you’ve never posted here. Now you have twice, with unhelpful posts and false accusations of me being rude and defensive. So I’m thinking who is this guy, so I check out your history, read your posts. First of all, you claim you don’t know anything much about BMS’s. Hmm, then you go on to say that your “skill” is to identify the needs of the people, and help them fulfill there needs, oh so helpful you are. So I’m still giving you the benefit of the doubt and maybe you could steer me in the right direction, but alas, I find your “helpful” Group Buy Scheme you have been touting on other threads.
I don’t know who your buying your cells from, or how much your jackin the price up, but I know where I got my cells from, and they were
1. $110 cheaper for 16 than any of your quoted U.S. Zipcodes (so I saved more and purchased 32)
2. Covered under Alibaba.com Trade Assurance
3. My communication text strings for all the negotiations between seller and myself are documented, in MY name, not a 3rd party, so if problems arise, I won’t have to deal with YOU.
4. I have the seller telling ME, these are GRADE A, NEW CELLS, not what ever they told YOU
5. Paid directly with MY credit card and Its safety features and refund ability, without having to involve YOU.
6. Shipping time is the same, well, yet to be determined
7. Oh, did I say I PAID LESS.
If YOU wanted to be mr helpful, you would steer people to reputable sources, help them on how to communicate with the Chinese way of negotiating, and you would be better off making a few bucks to help pay for your own cells elsewhere. Maybe I should just start posting on your thread,.... I think I will, not bog up this one. I think it would be helpful

I told you what I saw and responded to. I had not reread the whole thread at that point.
I have no idea when you bought your cells but I am not sure you could get that same price now. I know that I couldn't right now from the company you cited even with making a large purchase. If you can, that is GREAT! If I find out that is true I will go back and try to make a better deal.
You don't want to participate in what I am doing, that is fine. No one said you had to.
I will take a credit card too, and I have offered to let guys pay for their cells when they arrive if that is what is necessary. Not sure you can get any safer than that.
I apologize for not looking back in the thread to find more context for your question. I struck a nerve, and you struck back....fair enough.

 

[Michael B Caro]

Look mister, you’ve never posted here. Now you have twice, with unhelpful posts and false accusations of me being rude and defensive. So I’m thinking who is this guy, so I check out your history, read your posts. First of all, you claim you don’t know anything much about BMS’s. Hmm, then you go on to say that your “skill” is to identify the needs of the people, and help them fulfill there needs, oh so helpful you are. So I’m still giving you the benefit of the doubt and maybe you could steer me in the right direction, but alas, I find your “helpful” Group Buy Scheme you have been touting on other threads.
I don’t know who your buying your cells from, or how much your jackin the price up, but I know where I got my cells from, and they were
1. $110 cheaper for 16 than any of your quoted U.S. Zipcodes (so I saved more and purchased 32)
2. Covered under Alibaba.com Trade Assurance
3. My communication text strings for all the negotiations between seller and myself are documented, in MY name, not a 3rd party, so if problems arise, I won’t have to deal with YOU.
4. I have the seller telling ME, these are GRADE A, NEW CELLS, not what ever they told YOU
5. Paid directly with MY credit card and Its safety features and refund ability, without having to involve YOU.
6. Shipping time is the same, well, yet to be determined
7. Oh, did I say I PAID LESS.
If YOU wanted to be mr helpful, you would steer people to reputable sources, help them on how to communicate with the Chinese way of negotiating, and you would be better off making a few bucks to help pay for your own cells elsewhere. Maybe I should just start posting on your thread,.... I think I will, not bog up this one. I think it would be helpful

Rereading my last post, it doesn't sound much like the apology I meant it to be, I should not have made the post you objected to without looking back for the context at that point.
I can delete my posts, or leave them so people can see I screwed the pooch LOL. Whichever you prefer. I am sorry.