The Electrodacus SBMS thread (SBMS0, DSSR50, etc)

[Airtime]

I assume Type 1 thru 4 go high when condition is met. Is it possible to invert these outputs?
Thanks!

They are optocoupler outputs with two output pins, so it depends what you connect. Outputs are connected when enabled, open when disabled. You can't invert the logic in SW in the device, which I think is your question. What would you be driving with it?

Not sure of your background or if you are familiar with optocouplers. If you just need to close a switch or energize a (small) relay when 'condition is met' i.e. charge enabled or discharge enabled, then no additional components needed.

If what you want is a logic signal that is low when enabled and high when disabled, then you can tie low side to ground, pull up high side to desired logic high voltage with a resistor, and take the output from the high side. Resistor sizing depends on input impedance of whatever you are driving.

When enabled, the optocoupler pins will be connected, pulling the output low. When disabled, the optocoupler contacts will open, and the resistor will pull the output high. You can invert that by having a pull-down resistor instead of a pull-up resistor.

 

[Jdhorner8]

They are optocoupler outputs with two output pins, so it depends what you connect. Outputs are connected when enabled, open when disabled. You can't invert the logic in SW in the device, which I think is your question. What would you be driving with it?

Yes, I was thinking in terms of software and didn’t realize both pins were available for each output. I thought they were wet contacts rather than dry.
I’m not familiar with optocouplers, my experience is in line-voltage AC controls with industrial relays.
I have a Xantrex SW3012 inverter/charger I would like to control from the SBMS0. I have a Xantrex SW remote control panel by which I can control the inverter using a 12V sense input, but can’t find a way to kill the charger other than Dacian’s suggested relay on the AC input.
I’m not particularly fond of the heat generated by SSR’s and I’ve been trying to find a way to use a latching relay on this 30A AC circuit. In lighting control we have contactors that will latch closed with control signal present, then clear the coil automatically so there is no coil heating and the contacts are mechanical so there is no heating there either. When the control signal goes low the contactor opens. Blue Sea makes a battery combiner on this principle I believe, but I’m not finding anything configured for DC in and AC out as needed for my application.
Does anyone know of a way to control the Xantrex charger directly through Xanbus or something? If not, what would you recommend for a relay on the AC input that is low loss and low heat? Thanks!

 

[childcarepro]

Hey guys, so I took a break from this project to set up equities investments. Looks like everyone else has been doing the same thing? It's been quiet in here!

I always want maximum features, but what I'm really looking for simplicity over power. I'm sticking with my Victron ecosystem because it's slick and polished and does just about everything I need including remote monitoring and control, so the SBMS0 would just be a BMS. Is Electrodacus's SBMS0 compatible with my goals? Or should I be looking at a 200A Daly for my 8S 280Ah setup? I want to like Overkill, but I have a Victron MultiPlus 24|3000 and lots of big loads (high efficiency 9KBTU 24VDC heat pump, MW/convection oven, espresso machine, 24VDC fridge, etc.) and plan on using 3000W sometimes, so would like to have 125A plus headroom, so 200A is ideal. Chargery also sounds like a good option, but again, simplicity over power.

 

[Dzl]

Hey guys, so I took a break from this project to set up equities investments. Looks like everyone else has been doing the same thing? It's been quiet in here!

I always want maximum features, but what I'm really looking for simplicity over power. I'm sticking with my Victron ecosystem because it's slick and polished and does just about everything I need including remote monitoring and control, so the SBMS0 would just be a BMS. Is Electrodacus's SBMS0 compatible with my goals? Or should I be looking at a 200A Daly for my 8S 280Ah setup? I want to like Overkill, but I have a Victron MultiPlus 24|3000 and lots of big loads (high efficiency 9KBTU 24VDC heat pump, MW/convection oven, espresso machine, 24VDC fridge, etc.) and plan on using 3000W sometimes, so would like to have 125A plus headroom, so 200A is ideal. Chargery also sounds like a good option, but again, simplicity over power.

If you want simplicity, and already have the features, monitoring, and customizability of a Victron based system, I think you have correctly judged that the SBMS0 should probably not be your first choice.

If I were in your shoes, I would:

1. Start by making a list of must have features
2. Rule out the BMSes that don't have one or more of these features
3. Select one of the simpler BMSes remaining on the list

 

[childcarepro]

If you want simplicity, and already have the features, monitoring, and customizability of a Victron based system, I think you have correctly judged that the SBMS0 should probably not be your first choice.

If I were in your shoes, I would:

1. Start by making a list of must have features
2. Rule out the BMSes that don't have one or more of these features
3. Select one of the simpler BMSes remaining on the list

1. Active balancing and 150-200A discharge current are the only MUST have features;
2. I ruled out Overkill because only 100A;
3. To my knowledge, the only ones that remain are Chargery and SBMS0

Am I missing some options? Of the two I'm aware of, I would say Chargery is simpler, but not by a whole lot? Chargery does have 1.2A balancing current, vs SBMS0's 200 mA, which is a nice bonus, though with debatable utility.

 

[Dzl]

1. Active balancing and 150-200A discharge current are the only MUST have features;

A lot of people misunderstand what active balancing means (the terms are slightly misleading). Active balancing means the BMS or Balancer transfers energy from one cell to another whereas passive balancing bleeds energy from high cells--Almost all BMSes are passive balancing. If you truly need active balancing, you rule out 90% of the BMSes (including SBMS, Charger, Daly, JBD Smart BMS (overkill solar) and Ant BMS).

If you just need a BMS that balances, than all of the above BMSes will work (passive (resistive) balancing)

2. I ruled out Overkill because only 100A;
3. To my knowledge, the only ones that remain are Chargery and SBMS0

One BMS that may meet your needs (as written) is the Heltec BMS, I don't recall if it is available for 24v or just 48v but it is a true active balancing FET based BMS and I believe is rated at 200A maybe higher. There is a thread on the forum dedicated to it. But only a few people from the forum have purchased it and most have been recent purchases.

Among high end options, there may be more choices. 123smartBMS, REC, Orion, and maybe TinyBMS are some to look into if budget allows most or all of these are $400+ one added bonus is at least a couple can integrate Victron components.

 

[childcarepro]

A lot of people misunderstand what active balancing means (the terms are slightly misleading). Active balancing means the BMS or Balancer transfers energy from one cell to another whereas passive balancing bleeds energy from high cells--Almost all BMSes are passive balancing. If you truly need active balancing, you rule out 90% of the BMSes (including SBMS, Charger, Daly, JBD Smart BMS (overkill solar) and Ant BMS).

If you just need a BMS that balances, than all of the above BMSes will work (passive (resistive) balancing)


One BMS that may meet your needs (as written) is the Heltec BMS, I don't recall if it is available for 24v or just 48v but it is a true active balancing BMS and I believe is rated at 200A maybe higher. There is a thread on the forum dedicated to it.

Among high end options, there may be more choices. 123smartBMS, REC, Orion, and maybe TinyBMS are some to look into if budget allows most or all of these are $400+ one added bonus is at least a couple can integrate Victron components.

OK sure, resistive balancing; "active" in the sense the BMS is doing something to keep the cells in balance!

I think I've saved enough on my cells that I can splurge on the BMS, though within reason. Which of the higher end options do you prefer? So far I've looked at 123 Smart and REC, the 123 Smart looks really slick, with relays per cell and individual temp monitoring.

 

[Dzl]

OK sure, resistive balancing; "active" in the sense the BMS is doing something to keep the cells in balance!

In that case every BMS I am aware of fits the bill on that point (though there are big differences in balance current)
If I got to rename the terms I would use active to mean what thought it meant, since that is more intuitive, since I can't , I just try to clarify where I can.

I think I've saved enough on my cells that I can splurge on the BMS, though within reason. Which of the higher end options do you prefer? So far I've looked at 123 Smart and REC, the 123 Smart looks really slick, with relays per cell and individual temp monitoring.

Higher end BMSes are out of my price range so I have never looked seriously at them. The one that piques my interest the most is the 123smartBMS (it is also one of the more affordably priced high end options I think) Its made by a European company, is modular, and supposedly plays nice with the Victron (but possibly requires you purchase an addon to do so, I cant remember). It is also one of the only BMSes I have ever seen that uss latching relays (if I recall correcetly).

Tiny BMS isn't exactly high end but it looks pretty cool too (priced in the ballpark of the SBMS and Chargery I think) but requires a bit more DIY'ing.

 

[childcarepro]

Higher end BMSes are out of my price range so I have never looked seriously at them. The one that piques my interest the most is the 123smartBMS (it is also one of the more affordably priced high end options I think) Its made by a European company, is modular, and supposedly plays nice with the Victron (but possibly requires you purchase an addon to do so, I cant remember).

Glad you named them first, as that's the first one I looked at. Looks like it and REC talk to Victron. I'm reaching out to 123smart, since they don't have any dealers in the US. I really like the modular approach of 123smart.

One YouTuber bought about $1000 worth of REC stuff after all the accessories; that's a lot of money in Slovenia (where REC is based).

 

[Dzl]

I'd be curious to hear more about that 24vdc heat pump you mentioned earlier

 

[childcarepro]

I'd be curious to hear more about that 24vdc heat pump you mentioned earlier

Ah, that's something being developed by Hotspot Energy. They're developing a 24VDC 7000-9000 BTU mini-split air conditioner for RVs with a cassette-style indoor unit that is a drop-in replacement for noisy, inefficient RV A/C. I envied people who use traditional mini split units in RVs but I literally have no wall space for the indoor unit in my 25' Sprinter Class A motorhome. It was supposed to come out this quarter.

Hotspot Energy is a company that makes a bunch of interesting products like the Free Pool Heater, a titanium heat exchanger that lets you replace your condenser unit and use your pool water kind of as a geothermal heat pump to pump heat into rather than an air exchange.

 

[Cal]

Hey guys, so I took a break from this project to set up equities investments. Looks like everyone else has been doing the same thing? It's been quiet in here!

I always want maximum features, but what I'm really looking for simplicity over power. I'm sticking with my Victron ecosystem because it's slick and polished and does just about everything I need including remote monitoring and control, so the SBMS0 would just be a BMS. Is Electrodacus's SBMS0 compatible with my goals?

Yep, been investing in wm.

I think SBMS0 is a great choice. You might right now be looking for simplicity over power, but once you become more familiar with the system you want options. If you can read and follow directions then Electrodacus will fit nicely in your system.

 

[childcarepro]

One BMS that may meet your needs (as written) is the Heltec BMS, I don't recall if it is available for 24v or just 48v but it is a true active balancing FET based BMS and I believe is rated at 200A maybe higher. There is a thread on the forum dedicated to it. But only a few people from the forum have purchased it and most have been recent purchases.

How did I miss this?!? I totally moved past your Heltec suggestion and on to your high end options. I just stumbled onto Heltec again from an eBay seller who sells Daly BMS's who suggested the Heltec because it has BT and his Daly 8S 200A doesn't. That's when I found the video from this forum (https://diysolarforum.com/threads/h...balancing-independent-active-balancers.11453/) showing active cell balancing actually working. WHAT?!? Stop the presses. How is one of the only active cell balancers one of the cheapest BMSes?!?

I think this is the simple, powerful solution I'm looking for. WDYT? And I'll probably order two just to have as a backup, though it does require soldering so it's quite not a drop-in replacement.

Having the wiring harness like in the video is a good idea, to be able to disconnect the battery from the balancer and vice versa. If I pre-wire the backup balancer with a harness, it should be a quick replacement. Maybe the BattGo is a good idea for monitoring; I don't know how good the Heltec's app is.

 

[childcarepro]

Yep, been investing in wm.

I think SBMS0 is a great choice. You might right now be looking for simplicity over power, but once you become more familiar with the system you want options. If you can read and follow directions then Electrodacus will fit nicely in your system.

@Cal, I agree the SBMS0 sounds amazing, and has a very mature interface. The up front work is rough; I skimmed the manual; it's dense, and I'm not sure I'm up to the task re: electronic know-how, with opto-couplers and all.

At this point I am intrigued by the Heltec's true active balancing and the 5.5A balancing current and low cost. I imagine it works well during charge and discharge, not just just equalizing voltages across cells with no charge and discharge current.

 

[sremick]

A lot of people misunderstand what active balancing means (the terms are slightly misleading). Active balancing means the BMS or Balancer transfers energy from one cell to another whereas passive balancing bleeds energy from high cells--Almost all BMSes are passive balancing. If you truly need active balancing, you rule out 90% of the BMSes (including SBMS, Charger, Daly, JBD Smart BMS (overkill solar) and Ant BMS).

If you just need a BMS that balances, than all of the above BMSes will work (passive (resistive) balancing)

Does the SBMS40 also not do the "active" balancing in the sense of your definition? I'm not sure I fully understand the degree that my SBMS does "balancing".... I'd like to understand my product better.

 

[ArthurEld]

How did I miss this?!? I totally moved past your Heltec suggestion and on to your high end options. I just stumbled onto Heltec again from an eBay seller who sells Daly BMS's who suggested the Heltec because it has BT and his Daly 8S 200A doesn't. That's when I found the video from this forum (https://diysolarforum.com/threads/h...balancing-independent-active-balancers.11453/) showing active cell balancing actually working. WHAT?!? Stop the presses. How is one of the only active cell balancers one of the cheapest BMSes?!?

I think this is the simple, powerful solution I'm looking for. WDYT? And I'll probably order two just to have as a backup, though it does require soldering so it's quite not a drop-in replacement.

Having the wiring harness like in the video is a good idea, to be able to disconnect the battery from the balancer and vice versa. If I pre-wire the backup balancer with a harness, it should be a quick replacement. Maybe the BattGo is a good idea for monitoring; I don't know how good the Heltec's app is.

I have a Heltec 200A with 2A active balance.
This BMS is completely different than all of the other Heltec BMSs.
It isn't clear who actually makes it. Another company JK sells it too.
I haven't tried this BMS yet. There are a couple good reviews around here and a couple bad.
I agree that it looks like the best one for the price. I'm not recommending it yet.

 

[childcarepro]

I have a Heltec 200A with 2A active balance.
This BMS is completely different than all of the other Heltec BMSs.
It isn't clear who actually makes it. Another company JK sells it too.
I haven't tried this BMS yet. There are a couple good reviews around here and a couple bad.
I agree that it looks like the best one for the price. I'm not recommending it yet.

Did you see this one: https://heltec-bms.com/product/3s-21s-5a-capacitive-active-equalization-active-balancer/

It claims 5.5A active balancing using capacitive balancing; 1A at 0.1V differential, higher at higher voltage differentials.

 

[ArthurEld]

Did you see this one: https://heltec-bms.com/product/3s-21s-5a-capacitive-active-equalization-active-balancer/

It claims 5.5A active balancing using capacitive balancing; 1A at 0.1V differential, higher at higher voltage differentials.

Yes, I saw them.
I am sure you could use it with any BMS. I think you are supposed to turn off the passive balancer.

 

[childcarepro]

Yes, I saw them.
I am sure you could use it with any BMS. I think you are supposed to turn off the passive balancer.

Wait, are you saying that one ONLY equalizes between cells, but does not maintain balance during charge or discharge? That seems like a very narrow use case.

 

[Dzl]

Does the SBMS40 also not do the "active" balancing in the sense of your definition? I'm not sure I fully understand the degree that my SBMS does "balancing".... I'd like to understand my product better.

Just to clarify, its not my definition, it is the definition.
I actually prefer to call passive "dissipative" or "resistive" balancing but these terms are less understood/common outside of technical spaces but I think they better convey the concept. Active is also sometimes called "non-dissipative"

I'm not positive about the SBMS40, but I suspect like the SBMS0, it is a passive balancing BMS (as mentioned above, almost every BMS is).

Just to reiterate the distinction one more time, Active balancing transfers energy from high to low cells (using capacitors or inductors) whereas passive balancing simply bleeds off energy (using resistors) from the high cells. An advantage of active balancing is it only wastes about 30% of the energy as opposed to 100% with a dissipative (passive) balancer, and active balancers usually have higher current ratings. There are trade-offs though. I am not informed enough to write about them here, but I recommend these links (click the links there is a lot more info than the short excerpts I pulled out as quotes:

Dissipative vs Non-Dissipative (aka Active vs Passive) cell balancing -- LiionBMS

Dissipative: energy is removed from the most charged cell and is wasted in heat
Nondissipative: energy is transferred between cells and therefore it is not wasted

Traditionally, dissipative balancing is known as "passive balancing", and non-dissipative balancing is known as "active balancing". Unfortunately, the meaning of "active" and "passive" balancing has been confusing and interpreted in other ways. The terms "dissipative" and "nondissipative" are not open to misinterpretation. Therefore, we would like to take the lead in attempting to change the usage of these terms in the industry.

Battery Cell Balancing -- Wikipedia

Balancing can be active or passive. The term battery regulator typically refers only to devices that perform passive balancing.
In passive balancing, energy is drawn from the most charged cell and dissipated as heat, usually through resistors.
In active balancing, energy is drawn from the most charged cell and transferred to the least charged cells, usually through capacitor-based, inductor-based or DC-DC converters.

Active Battery Cell Balancing -- Analog.com

 

[Dzl]

Wait, are you saying that one ONLY equalizes between cells, but does not maintain balance during charge or discharge? That seems like a very narrow use case.

I believe you have found the wrong product. Heltec makes active balancers, as well as an active balancing BMS (balancer vs BMS is another often misunderstood topic). The balancer is just a single purpose tool, not a replacement for a BMS. The BMS is more expensive than the balancer and obviously more fully featured. Search for the BMS @upnorthandpersonal is using, IIRC, it is in the ballpark of ~$200.

edit: I believe this is the correct link and this is a relevant thread (if you get past the first page or two where the conversation is a bit muddled).

 

[Cal]

@Cal, I agree the SBMS0 sounds amazing, and has a very mature interface. The up front work is rough; I skimmed the manual; it's dense, and I'm not sure I'm up to the task re: electronic know-how, with opto-couplers and all.

At this point I am intrigued by the Heltec's true active balancing and the 5.5A balancing current and low cost. I imagine it works well during charge and discharge, not just just equalizing voltages across cells with no charge and discharge current.

Back in the day, Bell motorcycle helmets had an ad:

If you got a $10 head, wear a $10 helmet.

Or:

How much is your head worth?

If you're considering Heltic, then I'd say do more research.

This link states balancing current is 0.083 A.

 

[Dzl]

If you're considering Heltic, then I'd say do more research.


This link states balancing current is 0.083 A.

While I agree more research is a good idea-- particularly for a BMS that is rather new here, I think you also may need to do more research before forming or stating an opinion.

You linked to one of their passive balancing BMSes, not the active balancing BMS being discussed. They make (if they are in fact the true manufacturer) dozens of BMSes and balancers. Some dissipative (passive) some non-dissipative (active), some 'smart' some not, some cheap some moderately expensive.

I'm not positive, but I believe this is the correct link to the Active Balancing BMS. Balance currents range from 0.6A to 2A, price ranges from $90-500 depending on model.

73.0US $ |Heltec 1A/2A Active Balance BMS Battery Protection Board 13S ~24S 100A 200A CAN RS485 APP Lifepo4 li ion LTO 48V 16S 20S 60V 72V|Battery Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[Cal]

Sorry dude, opinions require no research.

 

[ArthurEld]

Sorry dude, opinions require no research.

You sound like our politicians.