ElectroDacus Beginner's Guide V0.6

[Oberon Robinson]

Hi all, even though it's uncertain when more ElectroDacus systems will be available again due to the chip shortages, I've been gradually picking away at an updated version of the Beginner's Guide.

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.

[Dacian Todea]

Oberon,

Thanks for creating and updating this document. Seems some people find this useful and are willing to read such a long document (it is a surprise for me as no many people read even the first few pages of the user manuals).

I see you used appropriate fonts :)

I should read the entire document and provide feedback but I feel to lazy to do that and still have a lot of work with the PCB's on the DSSR50 and even some small adjustments to SBMS0 before ordering new batch.

Just started to read first pages.

In Overview point 2 the reason PWM is not needed or any other form of constant voltage charging is because Lithium hates constant voltage charging and for the particular case of LiFePO4 (what most people use) it is not even helpful since at most you may be able to push another 1% SOC by using some form of constant voltage charging.

PWM chargers where created as a simple charger for Lead Acid batteries. They will be fully ON for the constant current part of the charging so panels directly connected to battery same as DSSR20 is doing but that sort of charging will only get the Lead Acid to maybe 70% or 80% SOC depending on charge rate and battery characteristics and so from that point constant voltage will start and to active that in the simplest way possible they use PWM. They are basically turn OFF the charging for a small interval of time and turn it back ON in order to keep the battery voltage around 14.4V (or whatever the absorption voltage is for the specific battery).

The thing is that Lead Acid batteries hated being at any other SOC level other than 100% fully charged but in offgrid solar PV installations this was not possible due to the short day especially in winter so people where forced to use gasoline generators to at least once a week give the battery a proper full charge.

An MPPT also uses PWM but in a different way an at much higher frequency as it has a small energy storage device usually in the form of an inductor and also large electrolytic capacitors and so this allowed better utilizing a PV panel not matching the battery voltage for the constant current part of the charging but for the longer part the constant voltage charging MPPT offers no advantage as there only part of the available PV power is utilized so there is no advantage form MPPT over PWM.

Now the type of Lithium battery in your cellphone or most other portable electronic devices also uses constant voltage charging when it gets above around 70 to 80% SOC depending on charge rate (usually charge rate is fairly fast on portable electronics from 0.3C to above 1C). This constant voltage is the most detrimental part of the charging but for those applications it is considered that the extra 20 to 30% SOC is worth the reduced life of the battery. Most people will prefer a mobile phone that lasts for say 6h of gaming and has a dead battery after about 3 years than having the exact same phone but battery only charged with constant current so just 4h of gaming and 12 yeas of battery life.

The reason for that is that battery cost is not significant part of the phone cost and in 2 or 3 years a new phone will be more powerful and desirable not to mention likely no phone will have support for 12 years.

In solar applications things are different as you will not want to replace a super expensive battery every 3 years and there is no advantage or incentive to do so thus if you where to use those types of Lithium batteries you will not want to constant voltage charge them thus there is no point in having a PWM or any other method of constant voltage charging.  For the special case of LiFePO4 there is no even any capacity to gain as with the 0.1C to 0.2C charge rate with solar battery is already 99% of real SOC with just constant current and just using PWM or similar constant voltage charging method to gain an extra 1% SOC at most will not make any sense.

The most common mistakes people make are.

1. Incorrectly connecting the cell balancing wires. Especially since the blue EVE, CALB type cells with black terminal for positive quite a few have connected the cells competently backwards and that results in a broken PCB fuse (PCB trace) and in some instances the 33V TVS next to the fuse may get damaged as that is the one that clamps the voltage to about 1V reverse polarity and so fuse will usually be the one to fail and nothing else but there where cases where TVS also failed as a short circuit so it will need to be removed if failed before repairing the fuse and reconnecting things with correct polarity.

2. Incorrect shunts wiring. I see you have point 9.3 talking about this  What it is burned there is the current shunt amplifier (not the cell voltage sensor).  The example you show is a fairly extreme one in most case the fault is not visible or much less visible under magnification.  The PV fuse or breaker should also be close to the PV shunt.

3. Use of the SBMS0 or DSSR20 in high humidity condensing humidity environments.  This is usually for those that use it it mobile applications like RV, Boats and usually in colder climates where the SBMS0 or DSSR20 get close to or below freezing over night then maybe the space is heated with propane or something similar fairly fast so that water will condense on all cold objects including the SBMS0 / DSSR20 PCB's

Neither SBMS0 nor DSSR20 and future DSSR50 are designed for outdoor use of condensing humidity type environments so in this applications they should be installed in a sealed box so they stay dry at all times.

I do not have plans to build a version that is waterproof as that is not easy to do will increase the cost and make things much harder to repair or modify.

Next time when I will work on my webpage likely end of April I will add a link to this document.

[Oberon Robinson]

Thanks Dacian.

Of course I had to use the right fonts. :)

I've posted the guide over on Will Prowse's DIY solar forum, and it's been downloaded over 800 times there.  So there seems to be some interest.  I'm happy to hear that you're open to adding it to your site.

I'll update everything with the points you made.  The most common mistakes will be a great addition.  I'm also wondering about coming up with a troubleshooting list that's the other way around -- if someone is seeing X, they should check Y and Z.  Maybe sometime I'll go through all the posts here and put together a list.

[Chris R8]

Dacian, the reason i got the Electrodacus is Oberon‘s beginner guide which puts a lot information that’s spreaded around in several forums into one source. Your owner manual missing a lot important details and because Electrodacus is different as Most other BMS that’s really needed. Also what and where do you get all this little parts that’s needed additionally to the SBMS to manage and steer all your Victron and other gear. One of the only manual I read in last 5 years :-) and could be 20 pages longer and I would still read all of it.

The section on remote on/off control and how to do this Victron products and other most common used ones, especially inverter should be even more detailed. It’s the heart how Electrodacus works and manages all the installation.  And on the other side it’s very hard to get the specs of the remote on/off of each device and also how to modify them if they don‘t work out of the box. Should be actually a list or even a knowledge base eg which Victron products can you remote control directly, which need adapter cable, which an optocopler and resistor combo….

[Oberon Robinson]

Chris, sounds like you just volunteered!

[Chris R8]

oberon, volunteered to do what?

yes i can make a guide how to make electrodacus waterproof, actually very simple.just putting that together at the moment.

yes I will sent you an overview on main fuses as even those class T fuses are not safe as main fuse for a Lifepo4 bank, they only rated for 3000A short curcuit and till 400A size avaliable. But a Lifepo4 bank of 500AH delivers around 10000A when shorted, so the lightbow will bridge the class T fuse. The only fuse thats rated for that size are NH2 (till 10000A) and NH3 (till 20000A short curcuit) and are avaliable from NH2 40A-400A and NH3 100A to 1250A size rating. resistance is also much lower, you can simply see this how beefy they are compared to a tiny class T. Several boat manufactuers switched to them already eg. Bennetau.

on the whole victron stuff I struggle myself....just wasted over 20 hours try to figure out how to remote steer that Victron phönix grid charger. Nobody seems to know, even Victron forum no answer. At the end I just risked it and connected it directly via an EXT IO type 1 and thanks god it worked. If not what whould have happend, would I fry the SBMS, stands nowhere....still so much basic stuff missing, i am sure its somewhere.

But that created another problem, too less EXT io ports now. I planned with EXT IO 4 to control via type 1 all victron charge sources, EXT IO 3 and 5 for type 2 load (one victron direct, one inverter via Opto and SSR) and EXT IO 6 for type 5. But know I need 3 EXT IO ports 4-6 as type 1 to just control my charge equipment even if all are victron,  EXT IO 4 direct for gridcharger, EXTIO 5 with resistor to 5V and VE-direct adapter cable for the 5 MPPTs (100/50 and 30 need 5V) and EXT IO 6 with resistor and opto for 12V for the 2x DC-to-DC charger. (runs on battery voltage so 12V)..how do I connect now my loads and handle type 5 with one EXT IO port left when i need 3 for that???? Is there a solution/workaround to control all of the victron charge sources with one EXT IO ????

to be honest i spend enormous time on Elektrodacus and slowly getting fustrated as you actually have to have done a full installation to be able to plan one...so many little details and parts you just figure out when acctually doing it because there is no real complete guide. Helped my friend on his REC BMS install, he pulls real 800A on 12V through his system so not first time doing this but electrodacus yes. I liked current free and no big expensive and unreliable relays to switch big loads.

eg CAT 5 or 6 cable here in europe is always stranded wire, i needed to source 5 different packs of 100 ferules and was lucky one fitted because i only figured out when actually crimping and connecting the shunts that the crimping part of the ferules need to be minimum 11mm long otherwise the connector on SBMS doesn't hold it well...they are so tiny and far off standard that I only found 2 suppliers for the ferules of that size but none gave length of ferules so I ordered all that could suit (have now 500 ferules here for 16 pieces needed but never need them somewhere else). Again no hint on this anywhere, backup would have been soldering the stranded wire but thats pita to pull in so they connect properly...and actually forbidden in marine environment as they could break due to vibrations.

[Jhon]

Nice work Oberon, explains things a little different then Dacian's and is a great addition.

Some notes:

"It’s also possible to use smaller panels, and for example have two parallel pairs of two panels in series, all being controlled by one DSSR20, as long as the total maximum current they produce is 20A or less. "

Needs max voltage as well for clarity.

--

The SBMS0 zero-calibrates the shunts on power-up, so it’s important that no current is flowing after you connect
your shunts and cycle power — which should automatically be the case in a properly designed system.

Might need to explain that the SBMS0 switches the EXT switches on after calibration of the shunt?

--

"and adding a heat source on a thermostat to prevent it from freezing."

maybe change it to something like "controlled by a separately purchased  thermostat"

--

That must have been a lot of work writing that.  Next, video's on each of the sections?

[Habana7]

i use Hardcore LAN-Cable cat5/6 and others for the last 35 years in the Netherlands that is available everywhere , strange that you couldn't find that, Chris

Op donderdag 17 februari 2022 om 02:42:58 UTC+1 schreef kampfsc...@gmail.com:

[Henrik Voldsgaard]

Ooh - I am about to regret that I bought this Electrodacus, because it seems that you have to be super-expert to work with it. But I have decided to keep fighting for a solution for my very simple system setup. 

I have 2 questions and a victron issue to be solved before 'take off'

1. You talk about the huge amount of ferules you had to buy to find the right one. I am living here in Europe as well - can you supply me with specs on the right ferules (and where to buy)?

2. I have some 12 feet/4 meters from my Lifepo4 to where my SBMS0 should be mounted. My plan is to do exactly the same as earlier shown in this forum (see picture), connecting thicker cables from battery to a breakout board and from here connect the ribbon cable. Will this setup disturb the measuring proces?

3. You write about problems connecting to the remote on different Viltron products. My setup I super simple (no solar, no inverter) ao I only have to connect a charger and a DC-DC. I have made a simple drawing of my plan - can I ask you to give me some feed back ?

Thank's in advance :-)

[Dacian Todea]

Henrik,

Yes SBMS0 is designed for those with some knowledge not plug and play consumer device.

1. All you need is a solid core CAT5 or CAT6 cable that should be available anywhere in the world and those do not require ferules. Let me know what store you prefer and I can check and provide a link. Mouser and Digikey have this cables and they sell almost anywhere in the world.

2. Ideally all equipment should be within 1to 1.5m from battery that includes the shunts that will be just next to batter no more than 50cm then inverter (if you use one) the DSSR20 and or any other chargers. You can use thicker wires from battery then have a much shorter ribbon cable connecting to those but you will still want all the equipment close together as is not just the cell sense wires but also the two current shunt sense wires and all the remote ON/OFF control wires.

Some people have extended all wires even to 4 or 5m but there is a lot of work and chances for something to interfere with something else. Best to have everything where the battery is and then you can have say a long USB cable to where you want to monitor the battery.

3. Seems like you want to charge from the Grid and from alternator. I do not see anything wrong in the diagram.  Just get solid core CAT cable and use twisted pairs for the shunt sense and EXT IOx.  If you extend the cables to 4m use 18AWG wires and add 5A fuses next to each cell terminal before connecting the the cell sense wire in case you ever short those sense wires at some point in time.

   

[Chris R8]

@ Jan and Dacian: Actually happy I didn‘t found solid cat 5 cable and was forced to use ferules as I meanwhile found out it’s forbidden in mobil environments to use solid wire, even more strict in marine.

Everything in marine must be stranded and crimped, you can only solder the not flexible end additionally but you need to be really careful and OCD here. I did that with the sensing wire cable shoes to make 100% sure to get a sturdy and reliable connection and used 3:1 heatshrink with glue inside, additionally stabilizes the cable at the crimp.

You really need to watch out in which environment you install your lithium system and follow corresponding rules, norms and guidelines. They are there for good reasons….

Rough guideline: the less movement and vibration the more you use solid wire (stationary installs) and weld/solder, the more movement and vibration stranded wire and crimping => marine is worst, seal every open wire connection with heatshrink with glue and use tinned stranded wires with as much single strands as possible. Never use welding or ground/earth lying wires in marine. 

One example: I always had problems with my 12V watermaker, now I found the reason by random: it’s connected with a thick 50mm2 welding cable, totally oversized for the Max 12V/50A it needs. It consisted of 10 strands strands and 8 of them were broken over time somewhere in the 6m run, so depending on movement and vibration from 2 till 10 strands were connected, kinda 5 strands would be needed min so it runs properly. But if you where looking/checking the issue you are stationary in a marina at the dock so all 10strands were connected…you never find that issue by searching….

Ordered twice with digikey Spain, never arrived….

Ordering gets complicated and expensive If you are on an island, every delivery (if they even ship there) costs min. 20Euro quickly 40 with open end and needs 3-4 weeks time plus lovely customs….11kg of simple peel ply were 160Euro shipping because we needed it in a week but it took 11 days because custom decided to screw us over…so no refund from shipping company.

[Dacian Todea]

I'm not sure solid CAT5 is forbidden. I think thinker transmission cables are forbidden to be solid as those will be very different in vibration environments.

Each wire on a CAT5 will be much thinner than a strand from say a 19 strand 6mm^2 (10AWG) PV cable.

See a photo (it is an early prototype that is why it looks a bit different) on how solid core CAT6 cable is installed. It is properly secured to the SBMS0 body with two zip-ties and the connectors are spring type so connection will remain secure even in vibration environments. The weight of those wires is so low that they will not be affected by vibrations. And if the vibration where to be extreme (way more than on a typical RV or boat) then SBMS0 can be installed on a compliant / elastic front panel to reduce high frequency vibrations.  If those wires are affected as shown installed in my example below then you have a much bigger problem as components inside the SBMS0 will fail before those wires.

I get the issues with shipping as for me in the middle of nowhere is also not easy (and it takes way longer than advertised) but digikey should provide tracking number so you should be able to see what happened with the order.   

 

[Henrik Voldsgaard]

Thank's Dacian!

I get the point in having it all together close to the battery. It I s possible, but then I need to understand what kind of monitor I can place at the end of the usb-cable to receive the data from the SBMS0 - do you have any suggestions for a setup?

You ones gave me this advice connecting the Orion DC-DC:

"The Orion can be connected to EXT IO4 with the EXT IO4+ connected trough a 1Kohm resistor to ignition and the EXT IO4- connected to the H pin on the Orion remote port this way the charger will only work if the engine is working (ignition ON)".

The ignition is about 4 meters away from the Orion. What kind of cabling should I use? As I understand the cabling should be twisted but how can I handle that?

Thank's in advance

[Henrik Voldsgaard]

If I want to fuse each terminal (5A) can you please link me to an adequate fuse holder?

[Dacian Todea]

The ignition signal is nothing fast just slow ON/OFF indicating that engine is ON so it should not be a problem that it is 4m long.

The fuse will need to be next to battery terminal and I do not have a suggestion it depends on your battery and what sort of terminal you have and preferences as there are like many options.

 Someone used I think glass type inline fuse holders but you can also solder this sort of fuses and just add heat shrink tubing over  https://www.amazon.ca/dp/B0831HSHRP

The fuse holders may have been like this https://www.amazon.com/uxcell-Inline-Screw-Holder-Gauge/dp/B07SM5KYZ7  in any case there are many options so it depends on what you prefer.

[Henrik Voldsgaard]

Thank's again Dacian. One last question in this round: what kind/size of wiring will you recommend 

1. between ignition and SBMS0 EXT IO4+ ?

2. between Orion (H) and SBMS0 EXT IO4- ?

[Dacian Todea]

1. There will only be less than 12mA trough that wire in either normal operation or short circuit as current is limited by the 1kOhm resistor you will be adding at the ignition side  so any wire size will work.

2. Same barley any current so any wire will work tho likely 24AWG solid core wire as it works best with the SBMS0 connector and is what you have on typical solid wire CAT5/CAT6 cables.

[Chris R8]

In marine environment only stranded cable/wire due to CE-Norm (Europe) or ABYC (US) is allowed, independent from the size. Connection crimped and max not flexible ends soldered. Only soldering is forbidden, only crimping is recommended way.

Makes sense what you explained and on the SBMS putting solid cable in a spring loaded connector side this is definitely ok and the only way a solid cable can be connected safely in marine environment.the problem is on the opposite site of that wire where you connect it to a ring terminal (eg. sensing wire) or even put it in a screw in terminal. Crimping a solid wire is a no Go, soldering a solid wire to anything (or putting it into a screw down terminal which is effectively the same) screams for trouble, especially on small cables as this connection will 100% break one day. I learned my lesson here….And in worst case not 100% as it just cracks under the isolation/heat shrink and then dependent on vibration or heel you have contact or not. That’s the gremlins you only find by random, can be extremely costly and driving you mad. Additionally the surface of the connection will erode over time in marine so the single solid wire has less surface and therefor higher resistance causing a bigger voltage drop. Use stranded (tinned)wire and ferrules and you are ok.

Solid wire the permanent movement and the cables weight and force in relation to its diameter is around 300-400% at the solid connection Point. If the cable is small in diameter it will weaken over time and get little haircracks at that joint which get bigger over time erode and resistance rises. If the cable is thick then it’s force gets mechanically transmitted through the connectors to the device and connector or device itself will break. Screw down terminals the soldering on the board will crack etc.

[Habana7]

A few thought according to my own maritime experience from years ago,...

 Do not use solid copper wire, this will quickly break due to the vibrations in the boat,  keep vibrations away from your equipment, the distance between the attachment points of a cable is a maximum of 300 millimeters (i thought).

The sheath of the cabling must be oil-resistant and withstand a minimum of 70ºC.

The cabling must have the correct thickness, á cable that is too thin loses power, gets hot and is dangerous.

Make sure switch panels are accessible, goes without saying I guess,  it should be clear what the positive and what the negative wire is.

Regularly check that the electrical installation works properly and that there is no damage...

 

Don't compromise on your setup to save a few bucks, do it right or don't.

By the way, that's the most common mistake I come across in the forums and YouTube videos.

And of course follow the regulations, your insurance requires that...

 

@Oberon, thanks for the great Beginners Guide, very usefull.

 

Op maandag 21 februari 2022 om 11:50:09 UTC+1 schreef kampfsc...@gmail.com:

[Dacian Todea]

I worked in automotive electronics as hardware design engineer so I do know the impact of vibrations on solid wires.  While I do not know the requirements for marine environments I'm sure the recommendations are just done to be simple to enforce.

A very similar example will be electrolytic capacitors the the way they needed to be installed in an automotive electronic module (I worked on airbag control unit at Siemens Automotive)

The large capacitor was needed as energy storage in case battery connection was lost that capacitor should still be able to deploy a number of airbags so it is a safety critical application.

I was even able to find a photo on google with the exact support implemented for horizontally mounting the large capacitor and obviously the solid core legs of the capacitors where bent and soldered and all this was vibration tested.

And this is not that different from how the CAT5 cable is connected to the SBMS0 and in fact better since there wires are not soldered but connected in a spring load contact and the mass of the zip tied cable is lower than that of this capacitor. The other end can be done in a fairly similar way. And connections are for shunt's and EXT IOx so in case shunt connection is lost current measurement is lost or inaccurate but other that measurements and maybe cell balancing nothing else will be affected. For EXT IOx an open circuit means device (either a load or charger) will be disabled so battery is protected but loads or charged may be disabled from a broken wire.

The point is that installation can be done with solid core wire and be vibration resistant but it is easier to make a simple rule saying they are not allowed. Improperly installed stranded wires will also brake in a vibration environment and even easier than properly installed solid core wires.

As for the CAT5 cable itself you can look at as multiple solid core wires or as a stranded wire with 8 strands.

And of course you can use stranded CAT5/CAT6 cable with ferules.  You still need to attach the CAT cable like shown in my photo and similarly on the other end even if cable is stranded. 

[Allen Tindall]

I am planning to simplify my installation when I replace an old version of the SBMS0 with a new one that I just purchased.  As part of this, I need to share the EXIO4 output to both control the solar panels and a Renogy DC to DC charger.  Attached are 2 diagrams similar to the diagram in the beginners guide Section 5.4.  The preferred diagram connects the DSSR20's to the input and the Renogy DC to DC charger on the output of a single 817 Opto Coupler.  The other diagram connects the Renogy DC to DC charger to the output of one 817 Opto Coupler and the DSSR20's on the output of a second 817 Opto Coupler.  I believe that either diagram will work but I am not an Electrical Engineer, I am not certain, and I do not know if one would be more reliable.  Per a previous recommendation, the RCP of the DSSR 20's is not connected.  The RCP inside the DSSR20 will go to PV panels positive through some resistors so it is not doing anything other than powering the RCN.

[Dacian Todea (electrodacus)]

You will need a 470 Ohm from 12V to EXT IO4p to protect the EXT IO4 in case EXT IO4n touches battery negative.

Both versions will work if you only have one DSSR20.

[Allen Tindall]

Will I need a different resistor between 12V and EXT I04p and will both versions still work since I actually have 3 DSSR20's?  What wattage resistor do you recommend?

[Allen Tindall]

Before I cut the hole to mount the new SBMS0, I thought I should verify that the wire lengths will not be a problem.  I have attached a modified diagram using the single Opto Coupler which shows the addition of the suggested resistor and also show the approximate installed wire lengths.  The old installation has the old version of the SBMS0 mounted in the overhead near the 3 each DSSR 20's.  This resulted in a cable length of about 3 meters between the SBMS0 and the battery box which is located in the bottom of the closet.  Although the system worked, I am planning on mounting the new SBMS0 on the closet hinge door post which will result in a cable length of about 60mm.  However, the DSSR 20's are still in the overhead and will therefore have a cable length of about 3 meters from the point where the wire to RCN branches from the EXIO3n wire.  Any suggestions?

[Dacian Todea (electrodacus)]

The lowest resistor value you can use with 12V battery is 270Ohm so that you do not exceed 50mA in case EXTIO4n is shorted to GND.

The DSSR20's will sure work is more about the 817optoisolator as it need those around 3 to 4mA at the input to open correctly and it depends also on how much current the Renogy needs.

I will add a small diode to each RCN so that in case one of the DSSR20 gets disconnected from battery negative it will not push current trough RCN to the other two DSSR20 forcing them ON.

 The length of the RCN wire is not very important and 3m is not a problem.

[Allen Tindall]

Thank you.  Your input helps a lot.  This diagram is similar to the existing design except for the resistor connected to 12V battery and a diode going to each RCN.  The Renogy turns on and off properly.  Therefore, I think that worse case I will need to replace the 3K resistor going to an LED and then to ground on the input side of the 817 with a lower value resistor to compensate for the new resistor connected to the 12V battery so that the total resistance will be about 3K.  I will add a small diode to each RCN.

[Allen Tindall]

Based on the post by Barry Timm I was wondering if it would be simplest to just short both of the 3K resistors on the Opto coupler board and install 1K resistors externally.  I have attached a diagram.  Hopefully I have the direction of the diodes to the DSSR 20's installed in the correct direction.

[Dacian Todea (electrodacus)]

Allen,

You can short the output 3kOhm resistor if you need to but not the input one. 

The input of the optoisolator is an infrared LED with a voltage drop of just 1.2V. So the way you have things setup the optoisolator will see (12V - 1.2V) / 1000Ohm = 10.8mA and that is fine is just that 1.2V at the DSSR20 is way to low to enable them.

Use 270Ohm at the 12V batttery and if the optoisolator has not enough input current to properly open the output just add a 1kOhm exactly at the input while you short the 3kOhm.

The DSSR20's have equivalent of 7kOhm on the inputs.

[Dmitry Katsubo]

Dear all,

Dear Oberon,

Thanks for your guide. I have learned something from it. Just two questions:

• Are there any updates of the guide planned? If so, will they be published in this thread? (I failed to find any reference on main site)
• The guide reads in section Overview: "When the battery gets full, it switches off the charging sources". By looking at wiring diagram, I could find only DSSR50 that can switch off the panels, but that will effectively switch off the inverter 😪. Or DSSR50 is able to gradually control the current that is flowing through it (e.g. similar to light dimmer), so that the necessary current is anyway provided to inverter?
• Is there any risk to degrade the batteries if the current drawn by the inverter is pulsating, so it will cause the batteries to be a bit discharged, then fully charged and so on? Basically the same recommendation to disconnect the phone from the charger for old phones...
  

Thanks in advance for further explanations!

On Wednesday, 16 February 2022 at 04:54:40 UTC+1 Oberon Robinson wrote:

Hi all, even though it's uncertain when more ElectroDacus systems will be available again due to the chip shortages, I've been gradually picking away at an updated version of the Beginner's Guide.

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.

[Dacian Todea (electrodacus)]

Dimitry,

What diagram are you referring to ?

The SBMS0 will control ON/OFF all charge sources say using EXT IO4 as type 1

And SBMS0 will also need to be able to control ON/OFF all Loads say using EXT IO3 set as type 2

So I do not understand your question about DSSR50 switching OFF your inverter.

DSSR50 has nothing to do with the inverter.  You will connect the DSSR50 to solar panels on the input and to PV shunt that is connected to battery on the output.

Lithium batteries will need to stop charging when fully charged and charge will start again only when the batteries have discharged sufficiently to again accept a charge.

LiFePO4 batteries can handle even half million such low DOD cycles so there will be no degradation.

See the green light for a charge rate of around 0.25C and a 5% depth of discharge cycles it can handle 600k cycles and that is fairly conservative.

 

[Dmitry Katsubo]

Thanks for verbose explanation Dacian,

On Friday, 11 August 2023 at 00:14:34 UTC+2 electr...@gmail.com wrote:

Dimitry,

What diagram are you referring to ?

I was looking into the wiring diagram on the website. I think I still miss the point how batteries are disconnected from solar panels (while inverter stays connected) 😪 If DSSR50 is switched off, the inverter will start to drain the current from the battery, right? Would it be more efficient to disconnect the batteries only? Probably I miss something in my picture i.e. solar panels cannot be exclusively connected to inverter...

Thanks!