The Electrodacus SBMS thread (SBMS0, DSSR50, etc)

[mitiempo]

Electrodacus isn't just for off-grid. I am using it on a sailboat. It works well with Victron MPPT controller, and almost all Victron equipment for that matter.

On a boat there is limited area for solar panels so MPPT makes the most sense. I agree with Dacian that off-grid his system works well.

 

[orangezero]

Electrodacus isn't just for off-grid. I am using it on a sailboat. It works well with Victron MPPT controller, and almost all Victron equipment for that matter.

On a boat there is limited area for solar panels so MPPT makes the most sense. I agree with Dacian that off-grid his system works well.

It isn't specifically designed for hooking up to a grid, is probably what I should have said. I would lump rv, boats, vans, into the general "off-grid" category, because while they could be charged with mains power at times, they aren't connected to the grid. I should have been more specific.

I can't say anything bad about the Victron stuff, seems to be quality.

I assume you have the sbms0? Did you try the ssr20 which goes along with it or just the victron charger?

It seems if you link the solar voltage to the battery voltage (electrodacus 24v battery + 60 cell) you are often already at the maximum point point of the system when the sun is shining, so what real advantage is there to mppt in the electronics?

I assume you do get some extra energy early on and at dusk with mppt. My assumption is when it is full sun midday the ssr20 and the mppt charger would be around the same amount of output, all else being equal. And my hunch is total output per day is similar. I think I've only seen one guy on youtube actually check apples and apples and it seemed his mppt was around the same output as his sbms40.

 

[mitiempo]

It seems if you link the solar voltage to the battery voltage (electrodacus 24v battery + 60 cell) you are often already at the maximum point point of the system when the sun is shining, so what real advantage is there to mppt in the electronics?

I assume you do get some extra energy early on and at dusk with mppt. My assumption is when it is full sun midday the ssr20 and the mppt charger would be around the same amount of output, all else being equal. And my hunch is total output per day is similar. I think I've only seen one guy on youtube actually check apples and apples and it seemed his mppt was around the same output as his sbms40.

Virtually all boats under about 45 feet are 12 volts. All boats, especially sailboats, have limited room for panels. The ssr20 really doesn't work on a boat. I am using a 24 volt (nominal) panel of 360 watts with Victron MPPT.

Victron is very good quality and reasonably priced as well. And yes, SBMS0

 

[Dzl]

I'd like to know what these people are comparing the electrodacus sytem to.

In my opinion, the SBMS0 (and other iterations) is in a class of its own. I'm not implying its better than everything else on the market, its not, but that it is really quite unique, full featured, and well thought through. The design model/logic, the feature set, and the capabilities are unparalleled at this price point. Its not a great fit for some people (most people) but its a great option for many in my opinion.

It may be frustrating to have someone say "ignore MPPT" after decades

I think a mistake both proponents and those who disagree with his system design philosophy often make is conflating his products with broader system design philosophy or opinions (Dacian can be a little opinionated/dogmatic).

The SBMS0 can be used effectively, and has a great feature set, regardless of whether one agrees with all of Dacian's opinions. The SBMS0 works just fine with MPPT controllers desite Dacian's view on the matter, the SBMS0 is compatible with alternator charging via DC-DC charging despite Dacian's view on the matter, the SBMS0 is quite flexible in many ways, that is the beauty of it. Dacian has strong opinions about some things, but he designed the SBMS0 to be flexible (with a few exceptions (48V, temp disconnects)).

Point being I think people would do well to separate their opinion of the SBMS0 from some of Dacian's positions on things like MPPT which is a totally separate issue. I don't fully agree with everything Dacian says or thinks (or more accurately, I think he overgeneralizes/gets tunnel vision about his use-case and doesn't always understand the different design goals of other use-cases like marine and vehicle based systems), but I still think the SBMS0 is a great option, is really well thought out and feature rich, and one of the best values on the market.

 

[orangezero]

Virtually all boats under about 45 feet are 12 volts. All boats, especially sailboats, have limited room for panels. The ssr20 really doesn't work on a boat. I am using a 24 volt (nominal) panel of 360 watts with Victron MPPT.

How many panels are you using? I can see why space is the absolute limit in certain situations.

I'm still confused why you say the ssr20 doesn't really work on a boat. The few I've seen discuss it mention the ssr20 and an mppt produced around the same amount of power, each having their own advantages. I have only used the built-in solar charger of the sbms120 but believe it works in a similar way as the ssr20.

My hunch is there would be a much larger difference in energy production upgrading 230w 60 cell panels to 330w 60 cell panels of the same physical size than there would be in moving from a ssr20 to a mppt charger. I could be wrong.

I am certainly looking at it in the wrong way, because you already did your homework and have some rather efficient 360w panels, and may have had a lot of other equipment before the sbms0. But I still am unclear as to how there is much real advantage with a mppt charger given the same panels. If you did the switch and got 20% more power output per week with mppt, I'd certainly like to know

Mostly, I'm going from reading about how it worked, but also there have been a few tests like this.

Not trying to be combative. It is hard to get a lot of discussion from people with experience with these. I appreciate the feedback and info. Thanks for sharing.

 

[mitiempo]

On a 12 volt system with ssr20 you cannot use 60 cell panels. That works for 24 volts. You can use a 60 or 72 cell panel with MPPT.

 

[orangezero]

On a 12 volt system with ssr20 you cannot use 60 cell panels. That works for 24 volts. You can use a 60 or 72 cell panel with MPPT.

I thought you said you used a 24v panel. I was curious how much total array you had to get a sense when people say they don't have enough real estate for solar to make the electrodacus system work.

Did you ever personally use the ssr20?

 

[mitiempo]

I thought you said you used a 24v panel. I was curious how much total array you had to get a sense when people say they don't have enough real estate for solar to make the electrodacus system work.

Did you ever personally use the ssr20?

I am using a 24 volt (nominal) panel, for a 12 volt system.

I didn't say that you need a lot of real estate for solar to work with the ssr20. I said on a boat you have limited space for panels and need to make it work. I do not know a single panel similar to mine that will work with a ssr20 for a 12 volt system - they are all higher voltage panels. But with MPPT it works very well.

The alternative would be several smaller 12 volt panels in parallel with ssr20. I didn't want to do that - simpler with a good installation of one larger panel.

No I have not used the ssr20.

 

[1 watt]

I am using a 24 volt (nominal) panel, for a 12 volt system.

I didn't say that you need a lot of real estate for solar to work with the ssr20. I said on a boat you have limited space for panels and need to make it work. I do not know a single panel similar to mine that will work with a ssr20 for a 12 volt system - they are all higher voltage panels. But with MPPT it works very well.

The alternative would be several smaller 12 volt panels in parallel with ssr20. I didn't want to do that - simpler with a good installation of one larger panel.

No I have not used the ssr20.

As Mitiempo mentioned, the higher voltage panels (like 60 or 72 cell) can’t be used directly with a 12v SBMSO system.

On our old Sprinter we have two 280w 60 cell residential panels (in parallel to avoid shading issues), an MPPT, and a 12v battery (four 200ah lifepo4 cells in series). Using the EXTIOs on the SBMSO for relay control of low/high voltage disconnects and high/low temp disconnects works great!

For the past 3 years I just switch off the main battery breaker when we‘re done traveling and leave the SBMSO to do its thing. Even after several months sitting, with the battery not heated and temps down to -20f, the battery has sufficient soc to run a diesel heater for a day to warm the battery to 50f. From there either I turn on the panels or dc/dc charger when we hit the road.

 

[orangezero]

Thanks for the response.

For me personally, I saw so many advantages to a 24v battery with the electrodacus I easily forget some of the other configurations like 12v batteries are possible.

We agree 60 cell panels are often so much cheaper than 12v appropriate panels. My solution was 60 cell panels + 24v battery + smbs120 as they pair perfectly. I didn't consider the dssr20 because it wasn't invented yet.

My solution is not necessarily the "best" if I already owned a 12v inverter, or four lifepo4 cells (which can't easily be rearranged to another voltage)... or if I already owned a mppt controller. I was starting from nothing so anything was on the table. I didn't have any standards or previously owned equipment pulling me in one direction.

I'm considering the purchase of a sbms0 and some dssr20/dssr50 (for a relative). I haven't yet found a good reason to go with an mppt controller over some dssr20, unless perhaps I end up with some mppt/inverter combo due to needing an inverter anyway.

 

[mitiempo]

While I am using a Victron MPPT controller with a 24 volt (nominal) panel for the reasons I posted above, there are, after further thought, other reasons for this arrangement.

I like the control the Electrodacus provides as far as turning off the MPPT controller when a cell reaches the preset voltage. But what if the Electrodacus were to fail. With a ssr20 you would be left with whatever voltage the solar panel outputs.

With a Victron MPPT I can set the bulk voltage at whatever I wish - say 13.8 volts. That voltage will not damage the cells were the Electrodacus to fail for any reason.

I firmly believe that all charge sources should be set at a non-damaging voltage for the battery bank.

 

[Oberon]

Just as an FYI, I've uploaded an updated version of the ElectroDacus Beginner's Guide, Version 0.6

New in Version 0.6:

• Clarified and fixed some errors in the descriptions of advanced parameters,
• Added a table of contents,
• Added a section on mobile considerations,
• Added a dedicated section on controlling Victron devices,
• Added a section on understanding the advanced parameters,
• Expanded the shunt calibration instructions,
• Added more pictures and diagrams,
• Multiple minor additions and changes.

If you see anything in it that needs improvement, clarification, or correction, let me know!

I also thought about adding a Troubleshooting section, so it would be great to brainstorm what could be included. If you've ever had some ElectroDacus troubles that you've shot, please post them here, and I'll work on adding them to the next version.

 

[captainrivet]

In process of installing an Electrodacus SBMS V3.0d in my Offshore world circumnavigation 40ft catamaran with 12V 3p4S 816AH bank made of 12 x 272AH Lishen cells. Having electric galley uoperated with a 3,5kw HF inverter boosting a Victron Multiplus 12/3000/120/16 to 5,9kw via power assist. So I pull 450-500A and happy I don‘t have to deal with high current SSR and relays to switch loads like this, very expensive and failure rate is high…great advantage of the Electrodacus.

Attached the diagram. Could you please check if I done the remote steering of the Victron components and ExtIO of the Electrodacus correctly?

On boats a real game changer are bifacial solar panels as they work with diffusion light and you get most out of your limited surface area. Additionally they are less prone to shading and I see approximately 70-80% during passage compared to anchoring, before it was like 40% if I am lucky.
I have 3x Longli bifacial wp365W Front + 80W back Running on 40V, one panel also really delivers 450W on 1,7mx1m surface. each panel runs on its own Victron MPPT 50/100. I figured I get around 15% more output with the bifacials if each of the panel have their own controller then all on one. Also gives me more redundancy. These Longli bifacials are awesome, a real lucky punch.

 

[DW SD]

I notice in the SBMS0 manual (advanced settings) there is a Doze / Idle state that in default is triggered @ 15 minutes. Does this turn just off the display? Or reduce consumption in some other way? I see consumption is .3W @ 12V. I ask as I hibernate my camper sometimes for a few months. In that case, everything is completely shut down.
Is the Doze / Idle consumption estimated by the BMS SOC algorithm (I assume not as no energy would cross the shunt)?
In my case with 560Ah battery, .3W ~ 3%SOC / month.
Thank you,
Doug

 

[DW SD]

Is this forum thread still active? My questions above went unanswered.
I've noticed my Electrodacus BMS doesn't set SOC to 100% even when the criteria for End of Charge are met. I've only seen it get as high as 91%. How does it determine SOC? ***Update, I read the beginners guide more carefully. Apparently Over Voltage setting for duration of "Over Voltage Delay" triggers the 100% SOC***

I also, in real time, see massive voltage variation on the monitoring screen (70mV on one cell). If I measure cell voltage via a decent quality DVM, it get steady voltage to .001 mV please see video and photos here:
album with photos and video of Electrodacus monitoring screen, DVM and my battery.
Is my BMS operating normally?
I very much appreciate any thoughts / feedback.
Thank you,
Doug

 

[FilterGuy]

Is this forum thread still active? My questions above went unanswered.

It is not very active. Early on there were a lot of Electrodacus fans here on the forum (Including myself) but that seems to have died down. At the time, there were very few FET BMSs that could do high enough amperage to meet the needs of myself and others. Since the sbms0 had the ability to directly control an inverter and chargers to turn on/off, it seemed like a great solution even though it required a great deal of wiring and complexity. Since then, high amp FET BMSs have come out so I lost interest in the Electrodaucus. I prefer the simplicity of a FET BMS. (I suspect a lot of other folks have gone down the same path) Furthermore, with the prices of pre-built and rack-mount batteries coming down so much, fewer and fewer people are doing DIY battery builds.

Does this turn just off the display? Or reduce consumption in some other way? I see consumption is .3W @ 12V. I ask as I hibernate my camper sometimes for a few months. In that case, everything is completely shut down.

I don't think it does anything more than shut off the screen......but I can not be sure of that.

Is the Doze / Idle consumption estimated by the BMS SOC algorithm (I assume not as no energy would cross the shunt)?

I do not know but your assumption seems reasonable.

I've noticed my Electrodacus BMS doesn't set SOC to 100% even when the criteria for End of Charge are met. I've only seen it get as high as 91%. How does it determine SOC?

Sorry..... I don't know.

I also, in real time, see massive voltage variation on the monitoring screen (70mV on one cell). If I measure cell voltage via a decent quality DVM, it get steady voltage to .001 mV please see video and photos here:
album with photos and video of Electrodacus monitoring screen, DVM and my battery.
Is my BMS operating normally?

This is most likely due to a ripple in the DC. A lot of inverters do not have a constant draw on the battery. Instead, the draw goes up and down; usually in sync with the AC output frequency. This will cause fairly large variations in the instantaneous voltage. Many BMSs do not do a long enough average to smooth this out. I vaguely remember the SBMS0 being suseptable to this problem..... but I can not say for sure.

One way to test my supposition is to put a large DC load on the battery (without the inverter) and see if you still get the ripple.

 

[DW SD]

Hi,
Thanks a bunch for your thoughts! I sincerely appreciate the insights.
The cell-level voltage swings only seem to happen under some decent charging load (I haven't tested, yet your higher current discharge theory). 30 amps on 580Ah x 13.2V doesn't seem high. but a few amps and the swing isn't pronounced.
I will also try turning off the inverter.
Turns out the "Over Voltage" metric is what triggers 100% SOC along with over voltage delay timing criterion being met (5 seconds in my case).

Doug

 

[Sverige]

Hi,
Thanks a bunch for your thoughts! I sincerely appreciate the insights.
The cell-level voltage swings only seem to happen under some decent charging load (I haven't tested, yet your higher current discharge theory). 30 amps on 580Ah x 13.2V doesn't seem high. but a few amps and the swing isn't pronounced.
I will also try turning off the inverter.
Turns out the "Over Voltage" metric is what triggers 100% SOC along with over voltage delay timing criterion being met (5 seconds in my case).

Doug

A cell voltage which deviates lower than the others on a significant load and higher than the others when charging would point to a poor connection on the sense wire on one or other side of that cell. Try tightening the nut or bolt to see if the voltage delta reduces.

The electrodacus Google group linked from the front page of Dacian’s Electrodacus website is far more active for discussion of Electrodacus related topics.

 

[michael d]

Hi,
Thanks a bunch for your thoughts! I sincerely appreciate the insights.
The cell-level voltage swings only seem to happen under some decent charging load (I haven't tested, yet your higher current discharge theory). 30 amps on 580Ah x 13.2V doesn't seem high. but a few amps and the swing isn't pronounced.
I will also try turning off the inverter.
Turns out the "Over Voltage" metric is what triggers 100% SOC along with over voltage delay timing criterion being met (5 seconds in my case).

Doug

yes, the electrodacus google group is where you will likely get the best direction as there are many active posts there and you will be alerted as more topics arise....

I have 4 of the electrodacus sbms0 in operation without issues, but there are a lot of parallel wires to the electrodacus dssr20 and electrodacus dect16 >>>> a system with a lot of DIY involvement...definitely

and I have several DIY 16-cell and 32-cell LiFePO4 battery builds in 24-volt and it is all off-grid.

the all-in-one server rack style is easy for beginners and surely more beginner-friendly >>> the DIY build with individual raw Eve LF280K cells still gives a lot if you have the time and willingness to learn...

all of the server rack batteries with built-in BMS do not always pan out to the advertised hype as some videos more accurately point out/portray, but is a selling tool for the affiliate linkers to get a kickback for the advertising they do on youtube videos...
Have a great day!!! ?

 

[DW SD]

Do others’ voltages on the ED BMS monitoring screen vary so much under load and charge? Say 5% or more of rated capacity? IE > = 30A on 580Ah
Please see my 10S video in the folder linked here. https://www.icloud.com/sharedalbum/#B0sG60dj6J1Gcqq
I will cross post on the Google forum.
Thank you!!