Why did Will go with Electrodacus?

[Devin82m]

Hey everyone, does anyone know why Will went with a very cool Electrodacus SBMS for his 24v handtruck system? I'm confused because it's limited in output current compared to something like Overkill Solar. Maybe I don't fully understand what it is and does, or how it's setup.

 

[snoobler]

You could ask @Will Prowse.

I suspect it was a whim at the time he was working on it.

FWIW, Electrodacus has been updated, and it doesn't suffer from the same limitations. It now uses signaling to compatible inverters to turn them off rather than opening a relay. The limits are established by the choice of shunts and fuses/breakers.

 

[Devin82m]

OK, so the new Electrodacus setup should handle more 100 A+ like the Overkill Solar BMSs? To be honest their website is a joke, everything is on one page and all smash together so you're not quite what specs are what or where one ends and another begins. I'm not quite sure where to begin with their stuff. I know I need the mail unit, a shunt, and maybe fuses. Beyond that the other stuff is not well explained and I have no idea if I need it or not.

 

[snoobler]

Manual is pretty straight forward with steps and pictures:

https://electrodacus.com/SBMS0/SBMS0v03d.pdf

 

[Dzl]

I am not sure what you are referring to when you say limited output current.

I think you may not understand the SBMS0 (which is understandable because it is somewhat unique and the documentation is not very beginner friendly). Your understanding on current limitation is backwards (one of the main reasons people go with a solution like SBMS or Chargery is because they are not (practically) current limited).

The SBMS0 is not current limited in the same way the Overkill Solar (JBD Smart BMS) or other FET based BMSes are. It does not sit directly between the battery and the loads/chargers so it is not a bottleneck.

That said, I don't think the SBMS0 is the best choice for a beginner, not that its a bad choice, but it is more advanced, and pretty unique and has a steeper learning curve. Its the type of device you want to buy intentionally because you understand how it works and why you want it.

 

[Dzl]

There is a pretty good explainer on BMSes here:

Beginners Summary of BMS Functions, Types and Features

This is a beginner's summary of the common types, functions and features of BMSs. The descriptions do not attempt to list all information of all BMSs, but it is intended to give you a base understanding of BMSs The document is in 6 sections: 1...

diysolarforum.com

 

[Devin82m]

Oh cool, I missed the manual, thanks snoobler.

Ah, that helps Dzl. So do you suggest a specific high quality BMS? I am building a 24v system. I have some experience with BMSs, I built a small 10 Ah LiFePo4 pack last year, the instructions I was follow were not very detailed and the BMS just had a simple diagram for connections, so there was a bit of a learning curve. After taking a quick glance I do understand now that the Electrodacus controls relays, so they don't need to pass through current, so yes, my statement does not make sense now.

As for buying an Electrodacus, you may be right, I don't want to get in over my head. I also think I decided I may buy some SOK batteries first for this 24v system, I build batteries later, but I am open to suggestions.

 

[Devin82m]

I will add that one reason I was interested in the Electrodacus is because it could save cost on BMSs. Also I like to see the data, I may not understand it all yet, but I'm trying to learn. Also I like the number of methods you can collect the data. I am a technical guy being a DevOps Engineer and messing with electronics, but I still have a lot to learn. Again, any suggestions are welcome and since I have not purchased anything yet I am keeping an open mind.

 

[Dzl]

Oh cool, I missed the manual, thanks snoobler.

Ah, that helps Dzl. So do you suggest a specific high quality BMS?

No, I don't have one particular model that I recommend. I think it is very dependent on what your use case, goals, level of understanding, and budget is.

I think the most beginner friendly options are Daly and Overkill Solar. But I really like the SBMS0 and for higher end options there are a lot of good options but they tend to be more advanced+pricey than most of us need/can justify for small systems.

The Overkill Solar BMS is a good option if you are okay with the limited current (100A), it has very nice beginner friendly documentation (which is almost unheard of for a BMS) and support, bluetooth, and all the basic protections we usually look for, plus a good number of forum members are using it so there is good 'mindshare'. It doesn't work for everyone, but its a good default choice for a small to medium system.

 

[HRTKD]

Devin82m, I was looking at the Electrodacus website yesterday and found it to be confusing. What I really wanted was a diagram that explained the landscape of how everything fits together without having to pour through a manual.

I don't doubt the genius of the BMS, I just didn't get a big picture.

I'm hoping to upgrade to a different trailer in a couple years. When I sell my current trailer I don't want to have to spend hours explaining the system. With the Victron components and the Overkill Solar BMS it's fairly straightforward. With an Electrodacus system in there I would get a lot of, "WTF?".

 

[Dzl]

I will add that one reason I was interested in the Electrodacus is because it could save cost on BMSs. Also I like to see the data, I may not understand it all yet, but I'm trying to learn. Also I like the number of methods you can collect the data. I am a technical guy being a DevOps Engineer and messing with electronics, but I still have a lot to learn. Again, any suggestions are welcome and since I have not purchased anything yet I am keeping an open mind.

If you are willing and eager to learn I think it could be a good option for you. The only reason I caution against it is because many people overlook the learning curve and don't spend the time to understand the design model and quirks. From a flexibility and data monitoring standpoint its a great option I think (having never used it personally).

One thing to understand is that many Chinese BMSes are going for mass market appeal so they design fairly simple products that can be used in various ways, and if there is a market they will design for it. Dacian started the SBMS project to meet his own needs, and to solve problems he saw, he is smart and insightful but fairly opinionated (in a respectful way) and his products are designed that way. This means there are potential features that many people want that probably just aren't going to happen because he doesn't see a need for them, disagrees, or doesn't want to devote the time/effort to a feature he doesn't think is valuable. That said, its a great and extremely flexible and well thought through BMS. With a great featureset for the price from what I've seen.

So its not so much that I think its a bad choice for all beginners, just that its not what most beginners are looking for or prepared for and you should go into it with your eyes open to the learning curve and particularities of it. I believe when I first joined the forum, my first post on the SBMS was something along the lines of "I'm not smart enough to understand it, but...." I've learned a lot since then but since my plans and purchase have been put on hold, there is still a lot I do not understand about it.

What I really wanted was a diagram that explained the landscape of how everything fits together without having to pour through a manual.

There is a diagram in the first 3 pages of the manual I believe. You definitely have to be willing to spend getting warm and fuzzy with the manual if you want to learn about the SBMS.

I don't doubt the genius of the BMS, I just didn't get a big picture.

This is one of the things most lacking from the documentation and one of the things Dacian struggles with most (in my opinion). Communicating to non-engineers the high level conceptual overview. (he is actually fairly good on this one on one in the forum, not so much in the documentation though).

 

[Dzl]

One more thing I will add, as more people on the forum have become interested in it, and are starting to use it, it is becoming much easier to find answers and our collective understanding is finally getting a small foothold.

 

[Devin82m]

OK, yeah that makes sense Dzl, thanks.

HRTKD, yes, very much agreed. If you can explain how the thing works in a summary on your site without making it one giant paragraph mixed with pictures of several of your other products then I kind of pass. Also I skimmed through the manual, it's a readable, but there is Engrish throughout.

I think I will go with the Overkill BMS, I don't think I currently need more than 100 Amps based on just power my home office/ham shack. I plan on buying/building a much larger 48v system down the road for the whole house but figured I would make a roll around 24v solar generator where I can pull more than 1500 watts from, hence 24v. If I am overkilling it (mind the pun) then please let me know. I I just have 2 laptops, 3 monitors, a couple raspberry Pis, a desktop (600 watt PSU), and a 100 watt (usually running at 20 watts or under) radio. I have a small 3D printer and an injet printer too but I only use them on occasion. I just thought 24v just in case I need to randomly pull more than 1500 watt, at least thats what Will's site states. I keep saying 1500 watt since that is my current, still new in the box, inverter I bought this summer. I'm on grid, so this is not needed 24/7, but I live in the sticks and it snows a lot here, so power outages do happen. I figured I would go with one of the all-in-ones like the MPPT or Growatt like Will has demonstrated.

 

[HRTKD]

I also tried to get the landscape by watching his videos. OMG, it's like watching paint dry. I don't have an hour to spare. Plus, it doesn't look like he has posted any new videos in two years.

Another concern I had was company depth. For a while, it was just Dacian, right? If he got run over by a bus, POOF! there goes the entire company. I know there's a third party doing some development. I should have looked at their site for more info. I didn't remember that until I wrote this post.

 

[Devin82m]

I should add that some of this for me is prepardeness minded, I will be storing backups of whatever BMS I go with in Faraday cages. Now that I think about it, I may not want something overly complicated I have to print a programming guide out for to use. I assume I can hook an Overkill Solar BMS up and it will work fine with it's default settings? Lets say if I didn't have a phone/app to program it?

 

[Dzl]

I also tried to get the landscape by watching his videos. OMG, it's like watching paint dry. I don't have an hour to spare. Plus, it doesn't look like he has posted any new videos in two years.

Funny enough I loved watching his videos and even rewatched a couple , that's how I first found out about the SBMS. But they are definitely slooow. Something oddly soothing about them though ?

Another concern I had was company depth. For a while, it was just Dacian, right?

Pretty sure that is still the way it is which is a vulnerability (though the hardware, and theoretically the software are open source so in theory someone could pickup where he left off or we could see multiple makers coexisting--but those are big IFs).

I should add that some of this for me is prepardeness minded, I will be storing backups of whatever BMS I go with in Faraday cages. Now that I think about it, I may not want something overly complicated I have to print a programming guide out for to use. I assume I can hook an Overkill Solar BMS up and it will work fine with it's default settings? Lets say if I didn't have a phone/app to program it?

For set and forget simplicity I think Daly would be one option to look into. But no low temp disconnect, no datalogging, no bt/wifi, no-frills basic protection.

I am not sure if the Overkill BMS is or is not configured in such a way that it just works out of the box with no config or BT. But I"m sure someone could answer that for you.

 

[donaldbitterman]

I also tried to get the landscape by watching his videos. OMG, it's like watching paint dry. I don't have an hour to spare. Plus, it doesn't look like he has posted any new videos in two years.

Another concern I had was company depth. For a while, it was just Dacian, right? If he got run over by a bus, POOF! there goes the entire company. I know there's a third party doing some development. I should have looked at their site for more info. I didn't remember that until I wrote this post.

There is a beginners manual being put together.

Yes, it is just Dacian but I there is not much to fail by design. Also, the technology is shifting so rapidly that anything you build now is going to likely be out of date in 5-10 years.

It is an interesting system and gives you allot of flexibility to switch battery chemistries and how you manage them.

 

[snoobler]

Late to the game. Did some research.

I like the Electrodacus for several reasons. It's an interesting BMS. However, it's use as a solar charge controller is absolutely, positively not one of them, though the diversion option is "neat"

Reference: http://solarhomestead.com/the-evolution-of-the-solar-charge-controller/

Four generations of charge controller technology:

1. Shunt type - short panels to battery and divert to a shorted circuit when battery full, i.e. panels either shorted to battery or shorted to themselves.
2. Relay type - Same as above, but the PV is open circuit rather than shorted to itself.
3. PWM - like #2, but done via solid-state and hundreds/thousands of times a second allowing for true battery voltage regulation.
4. MPPT - DC-DC converter that optimizes PV input power by finding optimal voltage and current to maximize battery charging output power - the only option that will ever permit a given panel to perform near it's true maximum possible power.

The Electrodacus appears to be type 2 thus utilizing none of the charge controller technology developed in the last 25+ years or so. PWM and MPPT will outperform it significantly.

I'm very much not impressed. If someone tries to tout it as an efficient charge controller better than any other technology, they are either deliberately misleading you, or they are misinformed.

However, using it as a BMS to signal chargers/loads to shut off - win.

 

[donaldbitterman]

Late to the game. Did some research.

I like the Electrodacus for several reasons. It's an interesting BMS. However, it's use as a solar charge controller is absolutely, positively not one of them, though the diversion option is "neat"

Reference: http://solarhomestead.com/the-evolution-of-the-solar-charge-controller/

Four generations of charge controller technology:

1. Shunt type - short panels to battery and divert to a shorted circuit when battery full, i.e. panels either shorted to battery or shorted to themselves.
2. Relay type - Same as above, but the PV is open circuit rather than shorted to itself.
3. PWM - like #2, but done via solid-state and hundreds/thousands of times a second allowing for true battery voltage regulation.
4. MPPT - DC-DC converter that optimizes PV input power by finding optimal voltage and current to maximize battery charging output power - the only option that will ever permit a given panel to perform near it's true maximum possible power.

The Electrodacus appears to be type 2 thus utilizing none of the charge controller technology developed in the last 25+ years or so. PWM and MPPT will outperform it significantly.

I'm very much not impressed. If someone tries to tout it as an efficient charge controller better than any other technology, they are either deliberately misleading you, or they are misinformed.

However, using it as a BMS to signal chargers/loads to shut off - win.

Dacian goes into this. I have not looked into enough myself, but he explains his logic.

 

[snoobler]

The argument is it's cheaper to buy 25% more panels than you need to compensate for the efficiency loss because MPPTs can't possibly last 25 years on the basis of the electrolytic capacitor rated life. Never mind that there are inverters out there and PWM charge controllers that have lasted that long (they have capacitors too, and they last a long longer when running at less than rated 105°C).

He's essentially arguing that all solar charge technology developed in the last 25+ years isn't reliable enough to justify their cost.

It's clearly been great marketing given the fan base.