What is gonna be different with SBMS2 compared to SBMS0?

[Niko N.]

Hi!

What is gonna be different with the new SBMS2? Do you have any estimate for when you think it will be available?

Also; in reading the manual for DEXT I don't fully understand this sentence: "It also alow EXT IO6 to control one or two trip circuit breaker’s or contactor for secondary level protection" -- are the trip circuit breakers that can be controlled remotely? If you have made any circuit diagram where you have included either the trip circuit breaker or the contactor -- could you link to that please?

Thanks in advance!

[Dacian Todea (electrodacus)]

Niko,

No idea when SBMS2 will be available but unlikely that will happen before the end of this year.

The main difference will be the extra current shunt input so there will be PV1 and PV2 shunts thus the name SBMS2

Other small differences will be changing some of the connectors and changing the shape and look of the SBMS2 slightly to fit the new connectors and better match the DSSR50 and DEXT

The USB/WiFi module will probably no longer be available for SBMS2 and I will be moving the USB to the main board of the SBMS2 so all SBMS2 will have build in isolated USB (likely will be using an USB-C connector).

I work now on an application that can read the Data from USB and display it in a graphical format so soon I should have some small Dell x86 (Intel Atom) computers that will have a Linux OS installed and that application preinstalled so that you can just connect the SBMS0 or in the future SBMS2 to the USB port and be able to connect one or two monitors to that mini PC and have the info displayed on a large  format monitor. I already have a bunch of this mini computers and they are super low power just 2 to 3W idle and they will be available with all software needed preinstalled at 79 CAD. Hope to have them ready by April (that is what I work on right now).

[sailingharry]

Dacian,

I have my SMBS0 in hand (hope to connect to the battery today!), and realized a possible improvement.  It would require PCB modifications, so I considered it a fantasy -- but if you are working up a SMBS2, it might be worth considering.

An Ethernet cord is easier to route, and more robust than your current 12 conductor cable (but admittedly 4 fewer conductors, so only 4 cells!).  If you could either include an RJ45 jack in addition to the 12-pin, or make it as a build option, that is something that 12V users might find a benefit.

Just a suggestion.  I have my SMBS0 and am not likely to buy another just for cord options!

Harry

[Dacian Todea (electrodacus)]

Harry,

Others have mentioned the RJ45 connector (two of them will be needed) but they will be larger and I think they are less reliable than the the currently used 12pin IDC type connector.

The RJ45 is designed for communication so low current high speed data and thus it has higher contact resistance than the IDC connectors.

I was mostly thinking at removing the 2x8pin black connector as it will no longer be needed if the USB is moved to main board and about the 16pin Phoenix connector that can be replaced with a removable connector similar to one of the connectors I use now on the DEXT. That may make the connection easier as you can build the cable and then just plug in to SBMS2 and DEXT. And also changing the mini USB with USB-C as it is fairly common now not that USB-C connector will offer any advantage.

[Habana7]

I certainly wouldn't change that 16pin Phoenix connector,it is small and easy to use for everyone, an RJ45 connector requires experience/knowledge that is usually not available and requires RJ45 special tools to install the connector professionally, which I have myself. I also thought about WireWrap pins, but that also requires knowledge/experience and tools, and I speak from 45 years of experience in this area and have made the mistake in the past of assuming that others can do that easily, ..so keep it simple. Those connectors on the DEX might still be possible, but I think they are a bit too large and probably also to expensive.

Op dinsdag 4 februari 2025 om 19:40:49 UTC+1 schreef electr...@gmail.com:

[Dacian Todea (electrodacus)]

Jan,

Yes you are right that the 16pin connector on the DEXT is a bit more expensive than the Phoenix 16pin connector used on the SBMS0 and that in it self is not inexpensive due to the brand name.

But I was thinking of using 4x 4pin connectors that are also used on DEXT witch are less expensive and they are removable but those use screws connections instead of spring connectors tho version with springs are also available but then again price for those will be similar or slightly higher that the current Phoenix.

The 4x 4pin connectors will take about the same space as the current Phoenix 16 pin connector and they have the advantage that they are removable so maybe more convenient to install the wires and much more convenient to remove the SBMS0 from a setup if needed.

The main thing I do not like for the 2x8pin used on DEXT other than the high price is that it is tall so on SBMS2 it will take to much space in therms of depth compared to the 4 pin connectors.

There where no issues with the 16pin Phoenix so maybe I will end up using that for SBMS2 but currently I'm considering 4x 4pin connectors that are also used for DEXT. There will be one for PV1 and PV2 shunts one for battery shunt and ADC2+ADC3 and the other two for the 4 EXT IOx. Then there is the option to use this screw type terminals that quite a few people seems to like or there is the alternative to use spring type terminals just at a higher cost for some reason.

Maybe in the Photos the DEXT looks large but it is smaller than SBMS0.

[Habana7]

I have a DSSR50 in front of me from Giels setup (not installed yet but ready) but those connectors seem a litlle bit larger than the Phoenix connector,  spring terminals should be preferred i think..

Op dinsdag 4 februari 2025 om 23:45:09 UTC+1 schreef electr...@gmail.com:

[Dacian Todea (electrodacus)]

Jan,

The 16pin Phoenix connector has a pin pitch of 2.5mm and this screw type connectors used on DSSR50 and DEXT have a pitch of 3.5mm so it can accommodate the thicker wires (not that they are needed).

The 16 pins on Phoenix are all in one row so it is fairly long 42.5mm the width is about 13mm and height is just 15mm

The 4 groups of 4 pins will not be installed all in a line but arranged at 90 degree so from above it will be seen as a 4x4 connector 16pin total.

The length of each 4 pin connector is 15mm so just 2mm more than the 13mm Phoenix and all 4 will add up to around 46mm again just 3 or 4mm extra.

So in therms of area they take a negligible amount of extra space is just the height that is 19mm vs 15mm but that extra 4mm in height may be compensated by the fact that connectors are removable so maybe easier to install/uninstall.

Still way less tall than the 30mm 2x8pin connector on the DEXT.    Going from 15mm to 19mm is not a big deal but going to 30mm is just to much.

There is also the 12pin IDC connector for cell monitoring and that is at 20mm so 19mm for this removable connectors will not exceed that.

No removable connector will be able to compete with the 15mm height of non removable connector. If height is that critical for many I will consider to use the same Phoenix connector on SBMS2. 

There is still some way before I even build the first prototype of SBMS2. Target was to have the front panel be 90x90mm vs 102x70mm on current version.  This will allow for 4 mounting holes in the front at same distance as the ones on DSSR50 and DEXT so that it can potentially be installed on a din rail. See a very rough sketch I made of the front panel layout.

     

[Habana7]

Yes, I see what you mean, it should be possible with that 4x4 arrangement, you will undoubtedly find the best solution,  small correction, that the "12pin IDC connector" on the PCB is 23mm. haha sorry  ;o)

The sketch looks nice, I'm curious to see what it will end up being, have fun

Op woensdag 5 februari 2025 om 00:31:59 UTC+1 schreef electr...@gmail.com:

[michael clark]

it will be a huge improvement to be able to view on a large screen and have the SBMS able to mount on a din rail the organization and such of wires will be better I think I have purchased the din rails and mounts for the drrs50 and dext... and like this method better ... thanks Dacian for the continued improvements...

[Habana7]

All those things you mentioned can already be done right now without any problems.

Op woensdag 5 februari 2025 om 14:09:05 UTC+1 schreef pilgri...@gmail.com:

[Sasa Duric]

So, SBMS2 won't have MQTT anymore? It is quite downgrade, as far as I 'm concerned. It is quite common fearure these days, and for me must have. 

[Dacian Todea (electrodacus)]

There is the USB for external data and if that is what you prefer you can connect an external ESP32 or any other device to allow for MQTT.

The SBMS0 will still be available for some time also.

The ESP32 will just no longer be available as an internal option but an external board connected to USB may be available if there is enough demand.

The ESP32 is just to closed source to my liking and it changes fairly fast with new fairly different models being available and old models being discontinued. The SBMS2 will be available for quite a few years and I do not want to contain things that will no longer be available and I can not make a large stock pile for those as since it is an option I will not know how many will be needed. Currently is about 40% of the people that order the USB/WiFi module for the SBMS0 but at least for SBMS2 the USB will be included as standard no longer an option and since the is isolated it can be connected to anything (mini computer or an external ESP32).

Currently I work on a software to display graphically all the data transferred over USB. The mini computers that I will provide (refurbished Atom X5 based mini computer by Dell as they are X86 and have as low power consumption and performance as a Raspberry Pi4). This computers have Ethernet but WiFi will need to be external on one of the 4 USB connectors (one of them is USB3).

Since this will be a Linux mini computer MQTT can easily be installed and more flexible.

[Harold]

As you say :

"The ESP32 is just to closed source to my liking and it changes fairly fast with new fairly different models being available and old models being discontinued.The ESP32 is just to closed source to my liking and it changes fairly fast with new fairly different models being available and old models being discontinued."

Thanks you to have such a good liking !

[Dacian Todea (electrodacus)]

Harold,

Do I not understand the word "liking" correctly ?

Is the meaning "not my preference" or "not to my taste" correct ?

You just do not have access to the ESP32 hardware so you can never build a reliable or secure application.

[Harold]

I meant thanks you to have such good principle and value.

Sorry if I made some confusion

[Andrew Maticka]

I'd love to see a few more EXTI relay and temperature sensor ports with more programing flexibility. 

I think with a just a few more ports it would be one of the few BMS's meeting the boating standards for lithium and by far the cheapest. If an Electrodacus cook book solution was offered, I'm sure it would sell like hotcakes.

[sailingharry]

Andrew,

I have carefully read the current ABYC E-13 while designing and installing my Electrodacus-based LFP battery on my boat.  I believe that my installation is 100% compliant with the standard.  Can you point to any requirements in ABYC E-13 that you think are not met?

The new standard due out this summer should not require any additional functionality (and remove some recommendations), so that is good.

But agree with you on programming flexibility.  I have some in mind I'd love to see.  Maybe once I have a season of operating behind me, I'll post some thoughts on that.

[Dave McCampbell]

Hi Harry,

As you know I too have a cruising boat LFP installation with a SBMS0.  I would be interested to know how you handled the ABYC E13 standard for an alarm prior to disconnect including what equipment you used.

Thanks  Dave

[sailingharry]

If you carefully read the standard (OK, not carefully, just "read") the standard, you will find there is NO requirement for a disconnect.  There is a recommendation to "consider it."

The challenge with an alarm is that the important ones are impossible.  There are scant seconds between an impending alarm, and an actual alarm, for the most likely events (high/low voltage and overcurrent).  Other events are near impossible to occur (high temp).  And yet others are easy to manage from a "prudent mariner" standpoint (low temp and low SOC don't "surprise you" -- they are very visible and a long time coming).

I was going to implement an alarm with my 20% SOC inverter disconnect.  Then had circuitry problems (I had a really complex FET based thing that was going to wind my watch and serve caviar, and it flopped) and gave up.  Think about it -- when was the last time you had a "surprise" dead battery on your boat, where an alarm would have been useful?  And, when you did, what were the really bad consequences (besides "start the engine, charge up the battery)?

I participate in the ABYC board that just finished re-writing E-13.  I can tell you that we discussed alarms a LOT.  And, I like to think my opinions had some influence in the new standard regarding alarms.  I can't tell you what the new standard says, but I think that if you search for the word "alarm" you may be searching a long time.

A fundamental problem I had with the old standard, and a lot of it was changed in the new standard, is ABYC was trying to create an "idiot proof, never-fail, space-shuttle-grade LFP battery."  If our engine runs out of fuel in a narrow waterway, we don't get an alarm saying "low fuel level."  But we were putting in all kinds of requirements to ensure that if your battery dropped out on low voltage (while motoring!?) causing a loss of your chart plotter, you had an alarm (even if only 10 seconds).  This alarm could cost hundreds (there was talk of requiring a certain dB level, installed at the helm station!), provide near zero benefit, and we don't require similar protection for running out of fuel or blowing a battery fuse on an AGM bank.  The existing standard for LFP requires an "owner's manual" so strict that, in my opinion (and no one disagreed with me when I challenged the concept) that there is not A SINGLE LFP BATTERY on the market that meets the current standard.  The new standard is much more achievable, with a focus on real-world actual accidents and less on "what would happen if you were in a heavy sea state, on a lee shore, after 3 days without solar, when a meteor hits your battery?"  I often kept bringing the discussion back to "Bubba with his Bass boat needs a new battery for his trolling motor, and he IS GOING TO install  LiTime packaged battery -- can he do it under this standard?"  Mega Yachts are going to (and should) install much more complicated systems, but ABYC applies to a 1970 J/24 sailed on a shoe string budget.  Not everyone can afford (or need) a space shuttle.

[sailingharry]

I mis-typed.  My first line references a "disconnect."  That was meant to be "alarm."  There certainly are requirements for a disconnect!