The Electrodacus SBMS thread (SBMS0, DSSR50, etc)

[michael d]

Here ya go!

essentially all Lishen 272Ah and Eve 280Ah cells are m6 6mm diameter(6mm studs of 20 mm length work well). so 6mm is essentially the same as 1/4 inch shrink terminals for the ribbon cable. the fortune cells had larger 3/8 inch terminal studs that Will Prowse used in his youtube video. the ribbon cable is 28 AWG (supplied with the SBMS0) so one may need to take that into account also.

you still missed this point in your 2nd edition of the "Beginners Guide to Electrodacus v0.3d.pdf". most people who use Eve or Lishen cells will want m6 or 1/4 inch holes in their tiny sense wire lugs. 3/8 inch were mentioned by Will Prowse for the fortune cells with 3/8 inch connection studs; for the fortune batteries which cost a lot more money for less capacity.
the sense wire is a 28AWG ribbon cable so one would likely have to fold the stripped end in have to crimp it in the tiny ring terminals which typically only go as small as 22AWG.
it would be better to get the ring terminal to fit the studs (aka Grub screws, or set screws) on the specific battery.

heat-shrink ring terminals:

https://www.ebay.com/itm/Heat-Shrin...var=652224280434&_trksid=p2057872.m2749.l2649

the cost was $9.08 for 100 pcs on eBay including tax delivered.

 

[LB3]

For those doing a new builds I highly recommend using breakout boards like these for the ribbon cables:

 

[zzyzx]

Aha . . . now that may be helpful if I have trouble soldering/crimping those 28awg ribbon sense wires. THANKS.

 

[LB3]

Do we know the timing for Will’s SBMS 0 video review?

 

[Oberon]

most people who use Eve or Lishen cells will want m6 or 1/4 inch holes in their tiny sense wire lugs.

Good point, I have M8 Lishen on order so they do exist, but it's true that most people will have M6. I'll add that in.

I highly recommend using breakout boards like these

LB3 do you have a source for those boards? Also keep in mind that Dacian says not to combine the full-length sense wires with the power supply wires, which I believe are 1, 11, and 12.

 

[michael d]

Good point, I have M8 Lishen on order so they do exist, but it's true that most people will have M6. I'll add that in.


LB3 do you have a source for those boards? Also keep in mind that Dacian says not to combine the full-length sense wires with the power supply wires, which I believe are 1, 11, and 12.

wow, m8 would definitely be a lot better. did not know you specify that part on the Lishen 272Ah cells or Eve 280Ah cells for that matter. two different vendors sent me ones with m6. the vendor did indicate they have the cells tapped that they don't come that way from Lishen. so I guess one if they knew in advance could have asked for the bigger m8. the build it yourself from raw cells has only been since October 2020 for me, so I am still learning by doing and studying.

 

[geoffire]

Maybe this was addressed somewhere in this massive thread, but can the DSSR20 modules be used for output control as well (type 2)? Seems like they should, or is there another obvious choice for enabling smallish DC loads i'm missing? Latching relay to avoid parasitic losses?

I'm still trying to wrap my head around this no main cutoff scheme, but it does side-step the issue of the lacking high current BMS options in my largish 12v setup.

 

[Oberon]

can the DSSR20 modules be used for output control as well (type 2)? Seems like they should, or is there another obvious choice for enabling smallish DC loads i'm missing?

The DSSR20s can only handle 20A each, so they wouldn't be much use for loads - not sure if they would actually work for that purpose or not. Most people use a Victron Battery Protect, set to Li-ion mode - they're pretty reasonable in price, and you can get them in multiple current ratings.

 

[geoffire]

The DSSR20s can only handle 20A each, so they wouldn't be much use for loads - not sure if they would actually work for that purpose or not. Most people use a Victron Battery Protect, set to Li-ion mode - they're pretty reasonable in price, and you can get them in multiple current ratings.

Ok, that does look like a better option.

I do see the Victron is uni-directional though so it's only for loads. I was eyeing a Blue Sea latching "battery switch", but making it a complete battery disconnect which would add a true failsafe like a traditional BMS - DC loads are the last thing I'd want disconnected anyways (just the fridge ideally), issue there is I'd have to manually intervene to re-enable charging. I don't know, those are $$.

 

[Oberon]

I was eyeing a Blue Sea latching "battery switch", but making it a complete battery disconnect which would add a true failsafe like a traditional BMS

If you want to do both with ElectroDacus, you can. Set a Battery Protect to disconnect your DC loads at low charge, and set a remote battery switch to disconnect on fault condition. But that may be overkill -- if you just turn off your loads, that protects your battery from excessive discharge. Same with turning off your charging source(s) to prevent overcharging.

 

[geoffire]

If you want to do both with ElectroDacus, you can. Set a Battery Protect to disconnect your DC loads at low charge, and set a remote battery switch to disconnect on fault condition. But that may be overkill -- if you just turn off your loads, that protects your battery from excessive discharge. Same with turning off your charging source(s) to prevent overcharging.

Yeah, I like the theory of a full disconnect, but in actuality I don't think I need it.

 

[LB3]

LB3 do you have a source for those boards? Also keep in mind that Dacian says not to combine the full-length sense wires with the power supply wires, which I believe are 1, 11, and 12.

I did my build about 5 years ago and I can’t find the source of the breakout boards. But I see some on Amazon. I won’t post a link because I can’t remember if Dacian used the connectors with 0.1” spacing or 2 mm spacing.

I also got new ribbon cable termination connectors to make custom length cables. I believe I got some of those parts from a combination of Mouser and Digi-Key but I can’t find those either.

 

[Oberon]

I've posted the latest version of the Beginner's Guide to ElectroDacus in this forum's Resources section:

Beginner's Guide to ElectroDacus

The ElectroDacus system takes care of solar charging, lithium battery monitoring, and optionally, diverting excess solar power for other uses. Its modular components can function as a BMS, a charge controller, and a thermal controller. It was...

diysolarforum.com

@Will Prowse you might like to look it over if you're working on a new ElectroDacus review video.

Any additions, suggestions, and corrections are very welcome!

 

[michael d]

I've posted the latest version of the Beginner's Guide to ElectroDacus in this forum's Resources section:

Beginner's Guide to ElectroDacus

The ElectroDacus system takes care of solar charging, lithium battery monitoring, and optionally, diverting excess solar power for other uses. Its modular components can function as a BMS, a charge controller, and a thermal controller. It was...

diysolarforum.com

@Will Prowse you might like to look it over if you're working on a new ElectroDacus review video.

Any additions, suggestions, and corrections are very welcome!

the dmppt450 is not available from Dacian as an addon board at this time. maybe he said something about making a 60ampp dmppt version in the future. the dmppt function is built into the new sbms0 so if you utilize the dssr20 with diversion and the dect16 then one can divert the excess solar to heat water and to resistive heating for your home builds. please revisit and ask the appropriate question to Dacian to get a more correct section in your beginners manual. I think this was referred to in section 4 or somewhere in your newest version of the beginners guide to electrodacus ---- i will read more of it later.. keep up the good work
edit: i think it was in the sect 1 overview but maybe i am reading it wrong because in section 4 you talk about the dect16 and dssr20 with diversion.

 

[gdemean]

I've posted the latest version of the Beginner's Guide to ElectroDacus in this forum's Resources section:

Beginner's Guide to ElectroDacus

The ElectroDacus system takes care of solar charging, lithium battery monitoring, and optionally, diverting excess solar power for other uses. Its modular components can function as a BMS, a charge controller, and a thermal controller. It was...

diysolarforum.com

@Will Prowse you might like to look it over if you're working on a new ElectroDacus review video.

Any additions, suggestions, and corrections are very welcome!

Hi Oberon, first of...thank you so much for your efforts on putting together the very appreciated guide.
I have a questions about the SBMS0 controlling the Multiplus 3000/24v via EXTIO3 and EXTIO4 that i connected them as follow:
EXTIO3/TYPE2/90% connected to Victron Multiplus 3000 AUX1 with matching polarity.
EXTIO4/TYPE1/30% connected to Victron Multiplus 3000 AUX2 with matching polarity.
It seems that the SBS0 is not controlling the Multiplus Charger/Inverter according to battery SOC limits. (SBMS0 has all advanced settings left to default)
I'm missing something?
Many thanks...

 

[Oberon]

It seems that the SBS0 is not controlling the Multiplus Charger/Inverter according to battery SOC limits.

You're right, Type 1 & 2 go by cell voltage, which is the correct way to manage charging & discharging. The SOC settings in the EXTIO page only apply to Type 3 & 4, which should only be used for alarms or secondary functions, not battery protection. If you want to charge to a lesser SOC after the daily first full charge for calibration, you set that in the 'Max SOC' setting under the DMPPT menu. I know, it's confusing, I'm going to clarify it more in the next version of the guide.

 

[gdemean]

Hi Oberon, first of...thank you so much for your efforts on putting together the very appreciated guide.
I have a questions about the SBMS0 controlling the Multiplus 3000/24v via EXTIO3 and EXTIO4 that i connected them as follow:
EXTIO3/TYPE2/90% connected to Victron Multiplus 3000 AUX1 with matching polarity.
EXTIO4/TYPE1/30% connected to Victron Multiplus 3000 AUX2 with matching polarity.
It seems that the SBS0 is not controlling the Multiplus Charger/Inverter according to battery SOC limits. (SBMS0 has all advanced settings left to default)
I'm missing something?
Many thanks...

Thanks for the quick response...
What I'm looking for the sbms to turn off the charger when the cells are at 3.5V and
to turn off the inverter when the cells reach 2.8V
Currently it seems that the SBMS IS NOT doing that cell protection in conjunction with the Multiplus 3000
Therefor the battery (cells) are not protected from overcharge/discharge

 

[Oberon]

Currently it seems that the SBMS IS NOT doing that cell protection in conjunction with the Multiplus 3000

Did you program the Aux 1 & 2 on the Multiplus? See this resource: https://diysolarforum.com/resources...or-multiplus-and-quatro-inverter-chargers.61/

 

[gdemean]

Did you program the Aux 1 & 2 on the Multiplus? See this resource: https://diysolarforum.com/resources...or-multiplus-and-quatro-inverter-chargers.61/

I have the Cerbo GX can I program the Multiplus with that?

 

[Oberon]

I'm not familiar with the Cerbo GX, sorry - but I would think you should be able to!