List and explanation of the SBMS0 remote types?

[Barry Timm]

Pls advise where i can read up on the "Types" for the SBMS0 connectors. Eg what does Type 1 or Type 6 mean, etc?

Thx!

[Dacian Todea]

Barry,

Type 1 is mentioned in many places in the user manual and type 6 is only mentioned on page 16 as that is for dual PV array only so you should make sure you do not have a type 6 set anywhere even on unused EXT IOx as then SBMS will think you have a dual PV array setup so it will try to switch to that second one from time to time.

The dual PV array functionality I implemented just before starting to ship the SBMS0 so all have that and I think on the first few SBMS0 the default for EXT IO5 was set to type 6. I noticed that and corrected making that type 0 as most people will not use dual PV setup even if that is great if you have space for extra panels as it means you can get away with a smaller battery. Read page 16 in the SBMS0 for details about that  https://electrodacus.com/SBMS0/SBMS0.pdf

You can also wait the on screen scrolling help text that explains all types in a short sentence.  (just checked and noticed I did not added description to that build in help for type 6 but even if I add a description it will be short and not enough still need to read the page 16 to understand).

[Barry Timm]

Thanks Dacian

My question was about the entire list of types. I used types 1 and 6 as examples only. Would have liked to understand what the various types are and how they may be used. I think its reasonable to be able to understand the options available before purchasing the unit and powering it up. :-)

If there is any such doc or post covering the list of Types, then pls point me to it. If not, well, at least I asked (as I like to try to learn the features and functionality before receiving the unit to ensure it meets my specific needs and dont want to waste your time with simple questions.) :-)

[Dacian Todea]

Type 1 (HVD - High voltage disconnect) used to control any charger that can be DSSR20, an MPPT solar charger with remote ON/OFF, a grid charger or a battery to battery charger.

Type 2 (LVD - Low voltage disconnect) used to control any load like in most case an inverter or something like a Victron BP-65 for small DC loads.

Type 3 and 4 are the same as 1 and 2 but based on SOC instead of voltage and should only be used as alarms not to control devices that is what the SOC setting is for in the EXT IO just for this type 3 and 4

Type 5 is for fault conditions when something went wrong and you get to secondary high or low voltage limits named under voltage or over voltage lock. This is not necessary but can be used as backup in case one of the chargers or loads fail to respond to remote ON/OFF control (very unlikely that will ever happen) and the you can have something like a remote triggered circuit breaker than can be tripped by this type 5 signal and manual intervention will be needed to check the fault, repair and then reset the breaker or breakers.

Type 6 is for dual PV setup where you install two PV arrays ideally one 2x larger than the other and that 2x larger PV array will be set as type 6

Say you have a 24V 120Ah battery that ideally will be charged with max 40A that means 4 of those large 60 cell panels so two DSSR20 for each set of two parallel panels controlled by SBMS0 EXT IO4 set as type 1 now if you want to have a larger PV array to help with those days where there is less sun but do not want to increase the battery size as that is much more expensive then you can just add another 8 panels and 4 DSSR20 as a second PV array and this can be controlled by the EXT IO5 set as type 6

So what will happen now is that when is sunny the 4 panels in first PV array controlled by type 1 will be enabled and as soon as the amount of sun drops below 20A (the 40A limit will be set in DMPPT settings in the SBMS) the 4 panels will be disconnected and the 8 panels will be connected that now should provide around 40A if those 4 panels where providing just under 20A and now if there will be even less sun and this 8 panels controlled by type 6 drop below 66% 26.4A the the 4 panel PV array will also be enabled still getting around 40A if then there is a bit more sun one of the PV array will be disconnected to maintain the charge current below 40A

This can provide up to about 3x more energy in a cloudy or overcast day and it will provide more even in a sunny day as all panels will be connected in the morning and later in the afternoon when sun is at an angle and less solar gets to panels.         

[Barry Timm]

Perfect! Many thanks for taking the time to answer this, Dacian. That is very helpful.

Barry

[Paul Alger]

Thank you for the explanation of type 6!  

I have been having an issue with EXTIO3.  Anytime the incoming charge from the photo panels exceed 13 amps, EXTIO3 shuts down for a second then turns back on for a second.  It keeps doing that over and over again each second.

After reading this post and realizing that I got one of the first SBMS0's, I checked the UART settings and found EXTIO6 was set to 6.  

After changing that EXTIO setting to 1,  EXTIO3 started working normally and will now accept a charge above 13 amps.

It may be a good idea for everyone to check their SBMS0 to insure that no EXTIO's are set to 6 unless you are actually using that feature.

[nebulight]

This should probably just be added to the manual.

[Dacian Todea]

Paul,

It should have still worked if EXT IO3 was set as type 1 not type 6.  If there is an EXT IOx like you mentioned EXT IO6 set as type 6 and that is not used it should still work other than has one second stop before working normally.

Also I always give the EXT IO4 as example for charging and set as type 1 make sure you do use EXT IO3 for charging and it is not used for Loads like an inverter as you will not want that to get disconnected when charge is done and then not disconnected when voltage is low as that is type 2.

All EXT IOx are the same and can be programmed as whatever you want  just make sure the EXT IO3 is in your case controlling the charging.

nebulight,  it is sort of in the manual page 16 but maybe I should add a warning something bold to not have a type 6 set somewhere is you have a single PV array setup. Tho it should not the the sort of problem explained by Paul and should be just that 1 second disconnect while scanning for max charge current not stop charging if you use type 1 correctly.  As if set current is exceeded it will still revert to L1 (level 1) and not fully disconnect and when current is lower it will set at L3 so both PV arrays connected so it will still be charging just if you have a single PV array setup and set type 6 instead of type 1 you will possibly have this problem where charging will continuously cycle.

[nebulight]

I meant it should be in the manual just as typed. You go over the loads and chargers section separately then space out to page 16 for type 6. It would make it easier to understand if all the types were in one section (maybe at the beginning and state more detail later (with page numbers)

[Dacian Todea]

nebulight,

For most people type 1 and type 2 are the only one used it was just my mistake that in the default settings I had the type 6 set as I was testing that dual PV and forgot to set it back to 0

There is also on screen help on the SBMS so you can see a short description of each type just before setting them but again I forgot to add that type 6 to the on screen help as the type 6 was a last minute addon to the SBMS0 software so it was a bit rushed just wanted to have that there for all SBMS0 users and not wait for a later release to add it. I'm still glad is added as many people will not update the firmware and type 6 works great for those that want to use it.

I should add the description in manual at page 38 in the next version of the manual. 

[Philippe Damour]

Hello Dacian
I will have a dual aray because of 2 different roof orientation.
Aray one will be at 165° azimuth and aray two at 255°.
From your explanation, aray one DDSR20 should be controlled by EXT IO4 set as type 1, and aray two DDSR20 by EXT IO5 set as type 6.
Correct?
Regards Philippe

[Barry Timm]

Damian will correct me if wrong, but my understanding is that a dual array is a good option only if the sum of the total amps inflows from the arrays exceeds the recommended maximum charging rate of your batteries. Otherwise, if your pv current does not exceed the maximum recommended charge rate, you could simply connect the arrays DSSR20s together on one port.

[Dacian Todea]

Philippe,

The answer Barry provided is correct you do not need to have dual PV setup if your entire PV array will not put more than battery can safely charge at.

[Barry Timm]

Dacian, can you advise why you recommend to not use Types 3 or 4 for controlling devices?
Is it because the shunt and /or battery capacity value may not be correct and thus the SOC is not a perfectly reliable factor for critical device control, or is there some other reason?

I ask because i have a dedicated inverter for providing power to an A/C in my RV that will usually stay switched on 7x24x365 but want to configure it to switch off automatically if the SOC% cross below 50%, thus nowhere near a critical low voltage point for the battery, and I thought I could use Type 3 for that, after calibrating the shunts and confirming battery capacity level from, by using a SOC% value of 50.

Please advise.

Thx!

[Dacian Todea]

There are many reasons including accuracy (especially as many people do not even know how that is done and set incorrect shunt resistance values or battery capacity values).

For discharge so type 4 may be useful in some circumstances if people know what they are doing but type 3 is particularly bad as if you never do a full charge then there will be no SOC correction and  SOC errors even of small say 1 or 2% per day they will accumulate fast and at some point you may thing battery was charged to 80% but in reality it may be just 20% SOC after a few weeks of less than full charge.

As you have not the things setup correctly SOC indication will be reasonable accurate you can use the type 4 set at 50% to stop the A/C and even in worse case if SOC is completely wrong it will still stop the charging if any cell gets to 2.8V.

So there is a 99% chance that inverter will be stopped around 50% say 45 to 55% real capacity and if for some reason wrong parameters or disconnected shunt any cell is at 2.8V then it will still stop that and protect the battery tho in that rare possibility the battery will be empty 0% SOC.

The type 3 and 4 where designed more as audio alarms for the user to know battery is at say 50% and then take the decision if he wants to continue to discharge or to stop some of the appliances. Many people will have a single inverter not two like in your case.  

[Barry Timm]

OK, good. Thanks for the detailed explanation and warning, Dacian. 

I'm glad you clarified that Type 3 was SOC based Charging and Type 4 was SOC based Loads disconnect, as I wasn't sure which was which, from your earlier post above.

I'll never use Type 3 but will try the Type 4 (SOC based load disconnect) for my dedicated air conditioner inverter. I'm fine if it is a few percentage points "off" from accurate, as all I'm trying to do is to kill the A/C if the battery drops to around half capacity, long before I lose ALL power to other more critical devices and loads. 

The alarm is interesting but for me, not that useful as I am often not in the RV and might not hear the alarm.

If there was a way to have the Type 4 signal work with a device to send a text message to my phone, that would be VERY useful to me, but I've already used all EXTIO ports on the SBMS0 and so don't really have that option, anyway. 

I truly do continue to think that an Electrodacus quality extension board for more EXTIO ports would be VERY useful for applications like RV and yachting, where multiple charging and load sources are currently used, but we had that discussion already, and I know you believe that the future market for your devices is primarily for offgrid homes rather than mobile ! :) :)

Thanks again for the awesome support. I absolutely don't know how you manage it, and recognize that I've had literally dozens of questions that likely seem foolish to those with much more electrics experience than me, so many, many thanks! :)