Category: Electricity

A look into Siglent SDS2000X Plus Software Options

In this article, we have a look into the software options of the Siglent SDS2000X Plus digitial oscilloscope series.

The SDS2000X Plus series has been around for quite some time and – while still on sale – has been superseded by the Siglent SDS2000X HD series. It consists of a 2-channel entry model and three 4-channel models with varying bandwidth (100MHz, 200MHz, 350MHz). Interestingly the hardware in these models is exactly the same (with the one exception of the 2-channel model only having a single acquisition unit). For more details have a look at this video where the device is taken apart:

EEVblog #1309 – Siglent SDS2000X Plus Scope Teardown+Hack

As mentioned in the video, there seems to be the possibilty to upgrade the bandwidth of the oscilloscope to up to 500MHz and additionally unlock a few other options. According to the manufacturer’s web site the value of the software options can add up quite considerably to a multiple of the actual oscilloscope:

Siglent SDS2000X Plus software options

The author of the video, which partially seems to divide its audience by its tonal pitch, remains cryptic about on how to actually do this but only refers to a post on this forum. So the question remains, is this really doable? and if yes, how does it work?

Note1: In case someone is wondering if it is allowed to generate software keys, an option might be to contact the manufacturer to get clarification on this subject.

Note2: I bought my scope with a couple of software options. So, no need for me to generate keys, I would not have otherwise.

A Siglent SDS2104X in action

The questions

According to the forum there seems to exist confusion about the following areas:

  1. What is the SCOPEID?
    The SCOPEID is the 16-digit value you find when you open Utility, System Info and strip of the dash characters from “Scope ID“.
  2. What is the Model?
    According to this video the model just stays as it is. So no replacing of the pre-defined value at all (regardless of the actual model we have).
  3. Which firmware versions work with it? And do I have to downgrade first?
    As it we can read from the Siglent SDS2000X Plus Release Notes, beginning with v1.3.9R10 no downgrade can be done to any version older than that version. In the previously mentioned video we see that exactly that version is used for the demonstration.
  4. Which keys (based on bwopt) work for which option?
    The script generates keys that do not necessarily match 1:1 to the options in the oscilloscope. But a look and search into the user manual reveals that the abbreviations in the script correspond to the product numbers. So for example, MSO is the abbreviation for the 16-channel logic analyser option. However, some keys generated by the script do not seem to have any corresponding sotware option at all (such as MAX or WIFI).
  5. How to generate keys for options originally not included in the script (eg. MANC, SENT)?
    There are options present, especially the MANCH and SENT option, that are not being generted by the script at all. All one would have to do, is to add MANC (mind the missing ‘h‘) and SENT to the array of bwopt and have to re-run the script.
  6. Is there any order in applying the software option keys? Or anything else to consider?
    Everytime a new key is entered, immediate feedback on the screen shows if a key was accepted as valid. A reboot seems to be required to activate the associated function. However, it is not problem at all to insert multiple keys or software options without rebooting.
    A special note about the bandwidth option: as one can see from the web site, it is not possible to buy a 500MHz license upgrade for a SDS2104X. Only the 200MHz option is available. After appliying an upgrade the actual model number of the oscilloscope changes as well and a new bandwidth option appears for that new model. So essentially, an upgrade on a SDS2104X to a 500MHz version (SDS2504X) must be done via these intermediate steps: 200MHz, 350MHz, 500MHz. In the end, only the label printed onto the oscilloscope shows its true origin.
    An upgrade to a more recent version of the firmware afterwards is possible but optional.
    Note1: after upgrading to 500MHz there is no more bandwidth option thus reducing the number of license options by one. I mention this, in case you thought something went missing.
    Note2: the standard probes only work up to 200MHz and also the high-end probe goes only up to 350MHz. So, in order to be really able to use the full 500MHz one probably has to get hold of an active probe.

The script

The script itself is pretty basic. The magic MD5 hashkey is being mangled with the Model and the SCOPEID. And then for each bwopt a new key is generated. Interestingly, the gen function never makes use of its parameter x and opt is implicitly referenced from the global scope.

Code from replit.com linked by miyagi

The conclusion

Essentially, this has been a story about weak license keys. Though it might seem perfectly doable to generate keys for software options without reyling on the manufacturer, this is not something that can be generally recommended.

Custom flexible busbars versus pre-built busbars for LiFePO4 cells

Since we started building our own batteries we have been using custom busbars made of Klauke DIN 46235 M6 compression cable lugs and Eland 35mm2 H07RN-F copper wire cable. The initial reason for this having no busbars that really fitted the way we arranged the cells in our utz RAKO boxes (see here, here and here).

I never actually measured the difference in internal resistance of the ones we built and some we got with our EVE LF280K cells. Time to correct this …

The flexible busbars delivered with our cells have approximately these dimensions: 105mm * 20mm * 2mm. This should give us a surface area of 40mm2 and an ideal internal resistance of around 0.045mOhm (according to some online calculators).

When measuring this with our trusty and highly precise TR1035+ the result displayed is 0.08mOhm.

Pre-built busbars 105mm * 20mm * 2mm

The Klauke version which comes with tinned copper lugs gives us a reading of 0.06mOhm – despite the smaller cross-section of 35mm2. The ideal internal resistance of the copper wire could be expected to be around 0.051mOhm (according to some other online calculator), so we are much closer to the measured value.

Custom busbar 105mm * 35mm2

The display error of the TR1035+ is expected to be similar as the measured range of both busbars is quite similar. There is certainly quite an amount of uncertainty (not only due to the maximum resolution of 10uOhm) to it. But it is interesting to see that the resistance of the custom busbars seems to be lower despite its smaller cross-section – while being better insulated (not seen on the picture) and more flexible at the same time (as it can be bent in more directions).

Producing these custom busbars is certainly more expensive (a single lug costs around 1.17GBP or 1.27CHF) and involves more manual and time consuming labour. However, it is quite easy to double them and/or increase its cross-section to up to 70mm2 per wire (when using multi-stranded DIN EN 60228 conductors).

So, this is it for today with fascinating facts about busbars for LiFePO4 cells.

Electricity and our Saurer 2DM

This is sort of a never ending story for me – just as the installation of our workshop container on the truck bed by our trusty mechanic which has been “in the making” since October 2022.

It is clear that we want and need electricity in the container. Just how and how much is not clear yet. In the following, I will consider our rquirements and different apsects and constraints of the electrical installation to hopefully come to a conclusion. This is a rather dry article with a lot of numbers – so beware …

Here is what we know (or at least think we know):

  1. The truck has a 24V system
  2. Charging any “leisure” batteries via the truck engine on a regular basis does not seem to be a good idea, as the fuel consumption is already 33l/100km without the container (that makes an astonishing 8.56mpg in the UK)
  3. It is a EURO0 diesel so we will not be able to get into all the cities (regardless of its problematic weight, length, height and width anyway).
  4. Solar panels are still no real option (most of the time too way up in the North)
  5. Charging from an EVSE might not always be possible as most of these EVSEs are for cars and do not have space for trucks
  6. We want to be able to cook and wash in the vehicle
  7. We will have a 2kW diesel heater
  8. We will have a 900W single phase petrol generator
  9. We will be using Eve LF280K cells
  10. The inverter must at least provide 2'250VA or 1'800W (concurrently, but not neccessarily on a single phase)
  11. (optional) We would like to have 3-phase power in the container (as the cabling is already in place) – but also we know we would only use it very seldomly (such as for welding, then we need at least 11A per phase)
  12. We would like to be able to charge 60% of the batteries (from 20% to 80%) within 3h
  13. We will be using Victron MultiPlus-II (as we do not 2 separate AC inputs)

Here is a list of devices needing electricity:

  1. Refrigerator (able to run on 12V DC/24V DC or 230V AC)
  2. Microwave (1'000W)
  3. Water heater (immersion heater with 1'000W or 2'000W and/or kettle with 2'000W)
  4. Table grill (1'250W)
  5. Steam cooker (450W/900W)
  6. Bread baking machine (600W)
  7. Coffee machine (1'150W)
  8. Washing machine (750W)
  9. Water pressuriation system (850W)
  10. Computers peripherals (USB-C charging with 36W via AC or DC, or 60W AC)
  11. Lights (12V or 24V DC)
  12. Water pump (12V or 24V DC)
  13. Fan (12V or 24V DC)
  14. Diesel heater (12V DC)
  15. Starlink (60W AC, possibly 48V DC)
  16. Infrared heating panel (150W AC)
  17. Battery charger (12V/24V DC or 230V AC, depending on model)
  18. Other USB powered and/or chargeable devices (via 12V/24V DC or separate 230V AC charger)
  19. built-in 6t winch (powered by engine)
  20. (optional) electric shower (8'000W)

Sizing the electrical installation comes with a number of additional constraints:

  1. The crane in the workshop garage can lift up to 500kg
    this mean, all batteries, inverters, washine machine and water tanks must be less that weight
  2. No single battery can charge or discharge with more than 140A
  3. We can only charge from EVSEs with a Type 2 connector

A 12V system is very quickly out of the picture (and the largest and only MultiPlus-II with 12V is a 3’000VA system). Besides, the truck has 24V system anyway. So it is either 24V or 48V. Here is an overview of all current 24V and 48V MultiPlus-II models and their charge and discharge values:

MultiPlus-II 24V and 48V

Let’s first evaluate a 24V system:

Combination of 24V batteries and invertes
  1. 1* 8s battery
    • Capacity is likely to be too small
    • Single battery is not redundant
    • 1*3’000VA can draw too much discharge current
    • 1* 5’000VA can draw too much discharge current
  2. 2* 8s battery
    • 2* 3’000VA can draw too much discharge current
    • 1* 5’000VA possible
  3. 3* 8s battery
    • 1-phase charge requirement can only be met with EVSE 7kW 32A Type 2
    • 3* 3’000VA can draw too much discharge current
    • 2* 5’000VA can draw too much discharge current
  4. 4* 8s battery
    • 1-phase charge requirement can only be met with EVSE 7kW 32A Type 2
    • 4* 3’000VA can draw too much discharge current

So, in a 24V 1-phase system only the 5'000VA inverter would be possible with either 2 (14’336Wh) or 4 (28’673Wh) batteries.

For a 3-phase setup to support our Kemppi Kempact 253A we would need at least 4 batteries and 3* 5'000VA inverters.

And now let’s have a look at a 48V system where we have a couple of more inverter options:

Combination of 48V batteries and inverters
  1. 1* 16s battery
    • Single battery is not redundant
    • 2* 3’000VA inverters needed
    • 1* 5’000VA inverter possible
    • 1* 8’000VA can draw too much discharge current
    • 1* 10’000VA can draw too much discharge current
    • 1* 15’000VA can draw too much discharge current
  2. 2* 16s battery
    • 1-phase charge requirement can only be met with EVSE 7kW 32A Type 2
    • 3’000VA not as 3-phase setup feasible (otherwise 6 devices necessary)
    • 8’000VA only as 3-phase setup, but then too heavy
    • 1* 10’000VA possible
    • 1* 15’000VA can draw too much discharge current
  3. 3* 16s battery
    • 1-phase charge requirement cannot be met
    • charge requirement can only be met with 3-phase EVSE (16A or 32A) Type 2 (11kW+)
    • 3’000VA possible, but too heavy with combined battery weight
    • 5’000VA possible
    • 8’000VA only as 3-phase setup, but then too heavy
    • 10’000VA only as 3-phase setup, but then too heavy
    • 15’000VA possible
  4. 4* 16s battery
    • batteries too heavy
    • 1-phase charge requirement cannot be met
    • charge requirement can only be met with 3-phase EVSE (16A or 32A) Type 2 (11kW+)
    • 3’000VA too heavy with combined battery weight
    • 5’000VA too heavy with combined battery weight
    • 8’000VA only as 3-phase setup, but then too heavy
    • 10’000VA only as 3-phase setup, but then too heavy
    • 15’000VA only as 3-phase setup, but then too heavy

So, this leaves us with really 3+2 choices:

  1. 2* 8s (14’336Wh) batteries in a 1-phase system with a single 5’000VA inverter
    • Battery and inverters would weigh roughly 140kg
  2. 2* 8s (14’336Wh) batteries in a 3-phase system with three 5’000VA inverters
    • Battery and inverters would weigh roughly 250kg
    • Not possible for 3-phase welding
  3. 4* 8s (28’672Wh) batteries in a 3-phase system with three 5’000VA inverters
    • Battery and inverters would weigh roughly 310kg
  4. 1* 16s (14’336Wh) battery in a 1-phase system with a single 5’000VA inverter
    • Battery and inverter would weigh roughly 140kg
  5. 2* 16s (28’672Wh) batteries in a 3-phase system with three 5’000VA inverters
    • Battery and inverters would weigh roughly 310kg
    • 3h on a 1-phase 16A Type 2 would charge about 38% (a 60% charge takes 4.7h)

From there, we can narrow this down even further:

  1. 1-phase system: 24V, 2*8s
    • Price: batteries 2* 1’364GBP = 2’728CHF plus inverter 1* 1’359GBP total = 4'087GBP
      • Con: 24V MultiPlus-II are considerably more expensive (than 48V)
      • Con: only have the capacity
      • Con: cannot run electric shower
  2. 3-phase system: 48V, 2* 16s
    • Price: batteries 4* 1’364GBP = 5’456CHF plus inverter 3* 812GBP = 2’436GBP total = 8'802GBP
      • Con: charge requirement can only be met with 32A Type2 on 1-phase
      • Con: additional 48V|24V DC-DC converter required
      • Con: heavier, 300kg+
        Con: higher self-consumption in 3-phase configuration

So – drum roll – my conclusion: for roughly double the money in a 48V we would get double the capacity and triple the charge and output power and pretty much can do everything we want the system to be able to do.

The 3-phase system can be reconfigured to a parallel 1-phase system, so we would even be able to use an electric shower (though very unlikely – we have our mobile shower). We can either charge 1-phase or 3-phase and have a longer window of electric autarky. And for most of the time we would leave the system in a 1-phase single device InverterCharger configuration. And additionally, for charging the other 2 devices would bet set to ChargeOnly (but be configured independently configured from each other).

The exact setup I will have to layout some other time, but right out of my head I would think of the following components:

  1. External power in with CEE 16-5, CEE32-5, CEE32-1, CEE16-1 and Neutrik PowerCON True1 TOP (the more the better)
    connected to an ATS
  2. AC out from MultiPlus-II connected to ATS
  3. Orion-Tr 24V|48V DC-DC converter
    charging from alternator (though not the norm)
  4. Orion-Tr 48V|24V DC-DC converter
    as power supply: to support 24V loads in the container
    as charger: as an emergency charger for the truck batteries
  5. Lynx Power In, Distributor
  6. Venus OS with Raspberry PI for RS-486 and DVCC

So, in case our Saurer ever gets finished – at least I know how to do the electricity …

Building a battery case for an 16s Eve LF280K configuration

The other day, I realised that I never wrote about the case build of our 16s 48V batteries, as I did for the 8s case and the 4s case. So, here it is – and I am actually describing 2 revisions as we made some adjustments.

First, the total weight of the cells alone would be roughly 16 * 5.3kg ~ 85kg. This is way beyond what a single person can – or at least should – lift. So, I deciced to split the battery into 2 separate cell blocks of 8 cells each (similar as I did split the 8s battery in the Toyota HiAce). With this approach, I would be able to:

  • reuse the 8s design (including the RAKO boxes)
  • be able to move or lift half a battery (which weighs roughly 53kg)

This battery has a nominal capacity of 3.2V * 16 * 280Ah = 14'336Wh and can be charged or discharge with up to 140A ^= 7'168W. We currently have 2 of these batteries running on our 3-phase setup with 3 * Victron MultiPlus-II 48/5000/70-50.

So essentially, I built 2 8s batteries with a connection cable between cells 8 and 9. The main negative and the BMS would be in one box and the main positive with the DC breakers would be in the other box. To avoid confusion, in this setup I went for coloured Anderson SB175 housings, with

  • Red
    2 * 35mm2 H07RN-F cable main positive
  • Grey
    2 * 35mm2 H07RN-F cable main negative
  • Blue
    Interconnecting both blocks
    2 * 35mm2 H07RN-F cable connecting from cell 9 positive to cell 8 negative

In all cases

16s Battery Connectors

To connect the cells to the BMS balancer cables I extended the balancer cables with 2.5mm2 wire via WAGO 221-2411 inline splicing connectors. I then measured the increased resistance of the additional cable length and adjusted the values in the BMS configuration for cells 1 to 9.

With these inline connectors I am now able to disconnect the blocks from each other so I can move them around independently, if needed.

On the BMS, I connected a USB RS-485 TTL adapater with a USB extension cable which leads to one of the USB ports of the Victron Cerbo GX. With the help of dbus-serialbattery and BatteryAggregator I can control the DVCC settings in Venus OS.

The rest of the build is, as I already mentioned, pretty much like the 8s build.

Revision 1

Here are some images of the completed build of revision 1.

16s Battery top view
16s Battery Block 1 main negative with BMS
16s Battery Block 2 main positive with DC breaker

Revision 2

These are the changes I am currently making for the next revision:

  • add additional connectors for the balancer cables to further facilitate the disconnection of both blocks;
  • use 16mm2 M6 Klauke DIN46235 compression cable lugs for the connection of the main negative (cell 16) to the B- of the BMS (only relevant to the older JK-BMS), to be able to disconnect and potentionally replace the BMS;
  • use a WAGO 35mm2 DIN rail connector in the main negative block on cell 1/9 for the outgoing cable;
  • use cable glands on the external connections;
    (this allows for easy disconnection and re-building the block as an 8s battery);
  • use ratchet straps for compressing and mounting the cells to enable easier maintainability of the cells;
  • use Anderson PowerPole PP180 connectors instead of SB175, so I can use mounting plates for the PP180 and do not have dangling cables on the outside of the case
    (these connectors are expensive and increase the price of the overall build by roughly 60GBP).

Hyundai HY1000Si as a cheaper replacement for the Honda EU10i

In one of our previous articles I wrote about the Honda EU10i as a backup generator for charging batteries via a Victron MultiPlus. Now as the supply chain has stabilised, the only noticable downside of this generator, that it will set you back a 1'000+ CHF (and even 1'000+ GBP in the UK). As we plan to equip our HiAce, Hilux, 2DM and possibly our trailer with such a generator this really adds up. So, I started looking for something cheaper – but hopefully equally robust, enduring and sturdy.

The requirements were basically unchanged. We want a generator that

  • is light
    less than 20kg including fuel
  • has a sustainable output of over 3.5A @230V
    as the MultiPlus-II 48/5000/70 has a minimum AC input limit of 3.5A
  • in combination with a MultiPlus 1600VA and PowerAssist must be able to provide more than 2'000W
    (which is already fulfilled when delivering more than 3.5A by itself)
  • generates more than 1'000Wh/l
  • must have an internal tank
  • generates more than 8'500Wh with the internal tank and an additional 5l tank
  • must be running petrol or diesel (the latter very unlikely in that weight range)
  • should be quiet
    the less noisy the better, no hard specs here
  • (optional) can be paired with another model to double the output
  • must have an automatic shutdown in case of oil issues and overload
  • must have an ECO mode
  • manual starter
    i.e. no battery needed for starting the generator
  • a seller with a service center from UK, CH or EU (preferrably DE/AT) for filing warranty claims if necessary

On AliExpress, eBay and Amazon there are quite some models for very little money. However, I also have very little trust (if there is such thing at all) in those product offerings.

So, when I did some modern research (i.e. googling around the internet) I came across three models:

  1. Hyundai HY1000Si (350 GBP)
  2. P1PE P1000i (300 GBP)
    formally known as Position One Power Equipment (kudos to the marketing department for such an intriguing brand name)
  3. Scheppach SG800 (200 EUR)

But before I go into detail here is a summary of the comparison:

Comparison of selected generators

Hyundai HY1000Si

This is the model I am most likely to buy (if I want to save money over buying the Honda EU10i).

Except for size, weight and price all its specs do not match the Honda EU10i (regardless of the slightly larger tank).

With a total advertised runtime of 3h it can produce 2'700W (which is the equivalent of roughly over a third of the nominal capacity of an 8s 280Ah battery – compared to nearly a half for the EU10i).

So unless we intend to use the generator only seldomly this would make a real (negative) difference in:

  • usability
    more frequent usage pattern, more refuelling operations
  • maintainability
    due to more service hours and material wear-off
    and efficiency
    longer runtime, more fuel consumption, more labour.

Compared to the Honda EU10i (which some consider the “gold standard”) there is relatively little information to be found about this generator (especially no thorough reviews).

Further note: From the advertised information the generator comes with some tools and replacement parts and even oil (which is an advantage over the Honda).

P1PE P1000i

Not a brand I have heard from before. It is a brand in the UK sold by the same company, GenPower Ltd, that is also the distributor for the Hyundai generators. And they heavily claim to use Hyundai engines as well. So much in fact, that at first sight it seems they *are* Hyundai generators.

The data sheet is to be questioned. A total runtime of 8.5h @50% load is advertised and no mentioning of any fuel consumption at 100% load. In the data sheet a fuel consumption of 550g/kWh is mentioned. With a specific weight of 740g/l for petrol this would equate to 0.74l/kWh which is not in line with the previous statement of 8.5h of runtime at 450W which would result in 0.78l/kWh. This would only “add up” with an assumed specific weight of 700g/l. And with petrols like E7 or E10 the specific weight will more likely further increase as in reduce. Furthermore, a generator running at 100% load is not expected to be as efficient as if it was running at 50% load. I am not saying that the 40ml/h make so much of a difference (it is slightly 5% off). I just get curious when the technical data sheet more looks like a marketing brochure. So, I would rather estimate a runtime of 4h at full load which would result in 0.83l/kWh or 1204Wh/l.

As P1PE seems to use the same Hyundai engines their increased efficiency over the HY1000Si would have to be in the “inverter” or electronics part of the generator. I do not find it likely that the cheaper model would have more efficient ingredients than the Hyundai model.

Scheppach SG800

A brand I have not heard from before either. Efficiency is not its strength and as I did not find it anywhere stocked, I merely list it here as an interesting option because of its form factor.

With only 800W this generator seems to be on the weaker end. But with only 8.5kg and a 3l tank it makes it up for its lack of efficiency and output capacity.

This might be an option where one really only rarely uses the generator. And then only to charge a battery (which is exactly what we aim for).

The price is debatable as I could not find it anywhere ready for order.

Summary

The choice for these small generators is rather small. If we were open for larger and heavier models the 2'000W range of inverters would provide a much broader selection (also with a higher price tag).

So, to come to a conclusion: it’s mainly price over efficiency and loudness. Is the spending of 2.5 times more justified for a generator which I only want to use in edge cases? For our use case, probably not.

WMF Lono Quadro mobile BBQ and the Victron MultiPlus Compact 24/1600/40-16

Though this could have been our first “unboxing blog post” in this article we only describe an already unboxed table grill.

Being able to have fires in the open less and less often it was time to find an electric BBQ alternative – with the constraint that it should run on a Victron MultiPlus Compact 24/1600/40-16 (or any other 1600VA sized inverter). After some frustration we finally found a nearly perfect match: the WMF Lono Quadro.

According to its spec sheet and product brochure, it uses 1250W – which is just under the nominal maximum power of 1280W that the MultiPlus can deliver.

Plus, the BBQ is relatively cheap. With a MRSP of 79.99 EUR it is available for as low as 60 EUR (PP included depending on your location). So, we ordered one of these table grills and gave it a try.

Upon powering up the device it uses its full power (regardless of the dial setting 1 .. 5) which results in a current draw of around 50A as seen on the BMS. The setting of the dial only seems to affect the intervals between heating (drawing current at 50A) and not heating (not drawing current at all).

The initial heating phase lasts naturally longer which results in the fan of the inverter kicking in at some point. But once the BBQ is at its operating temperature the fan is silent most of the time (as the heating intervals are relatively short). With 1250W nominal power consumption and a heat-up time of around 5min this consumes roughly 104Wh – about the same energy to boild 1.1l of water from 20°C.

During the use of the BBQ the inverter is pretty much at its power maximum and so has little to no resources left to power anything else. Though it seems possible to leave a fridge running, it might be better to unplug any consumers during cooking.

But all in all, with this table grill we now can do the BBQ inside (or outside) in our Toyota HiAce – even when we are on the move.

Some additional observations:

  • Weight
    The device is relatively heavy – especially the grill plate.
  • Size
    The usable size of the BBQ (270mm x 270mm) in relation to its overall dimensions seems quite large (while the whole device is still not bulky).
  • Power consumption
    Though the power consumption is rated at 1250W the heating intervals are relatively short which turn leads to a moderate overall power consumption.
  • Cleaning
    The grill plate can easily be removed and thus easily be removed (even in a dishwasher if you happen to have one in your car). Also, the drip tray can easily be removed and cleaned. Only the base plate is not meant for dishwashing.
  • Drip tray
    If the BBQ is not positioned horizontally (maybe due to the parking position of the vehicle) then the drip tray might have difficulties to catch all the fat that might float around the grill plate.

And this is it for today. Happy BBQing …

WMF Lono Quadro running from a Victron MultiPlus Compact 24/1600/40-16 at roughly 1250W/50A
Heat-up time is roughly 5min when turning the dial to the maximum position

Limiting the AC input of a Phoenix Smart Charger in parallel with a MultiPlus Compact

In a previous article I described the electric installation in our Toyota HiAce with a 24V battery and a Victron MultiPlus Compact 24/1600/40-16. At that point one piece was still missing: the Phoenix Smart IP43 Charger 24/25. It finally arrived this weekend and so it was time to install it; and configure it – which is normally not something worth going into lengthy detail.

However, in this case we wanted a kind of “special” setup which included the use of MultiPlus Assistants. So, in this article I will quickly describe what we wanted to achieve and how we implemented it.

In general, when connected to shore power we want to be able to limit the AC current drawn from the shore power. This is easily accomplished by setting a limit on the MultiPlus itself – or, as in our case, via the VE.Bus Smart Dongle. Though the Phoenix does have a VE.Direct interface and is able to be connected to a GX device, in our setup we did not want to use a GX device. So, essentially the Phoenix can only be controlled via Bluetooth and the VictronConnect app. But configuring the AC input limit on two devices (Phoenix and MultiPlus) is not only a nuisance from a usability standpoint, but also error-prone as one (or at least we) tend to forget things quickly. So, a different and better solution was needed.

Enter the MultiPlus Assistant in form of the Programmable Relay. With this, we can configure the built-in relay of the MultiPlus to open and close based on the availability of an AC input.

Note: we have to disable “Virtual Switch” in the MultiPlus to be able to use the MultiPlus Assistant.

The Phoenix has a Remote Input connector, that can be used to stop charging when the connection is “off”. So in our case, we enabled two Programmable Relay assistants:

  1. Programmable Relay, NC – On/Open
    After 5 seconds of AC input on the MultiPlus the relay is opened.
  2. Programmable Relay, NC – Off/Closed
    After 1 second of no AC input on the MultiPlus the relay is closed (which is the default state).

The wiring is as easy as to connect:

  • MultiPlus Relay COM < — > Phoenix Remote Input L
  • MultiPlus Relay NC < — > Phoenix Remote Input H

Note: on this page you find a description where the relay is located in the different MultiPlus models.

Below you find some screenshots with the configuration in VE Configure:

Disable Virtual Switch on MultiPlus
Add 2 Progammable Relay assistants
Programmable Relay ON after 5 seconds
Programmable Relay OFF after 1 second

So, five seconds after the MultiPlus has power via AC input it will open the relay which in turn will enable the Phoenix to start charging.

One second after AC input is gone the MultiPlus will close the relay so the Phoenix will stop charing (if it was charging at all).

The AC input of the Phoenix is connected to the AC output of the MultiPlus. So, when there is a AC input limit configured on the MultiPlus (such as 3A @230V) the MultiPlus and the Phoenix will not be able to charge with more than 3A. And from the MultiPlus perspective, the Phoenix is just an arbitrary consumer.

This can lead to some undesired behaviour if we were to limit the AC input to e.g. 1A. In this case, the MultiPlus would – when in Inverter mode – draw from the battery so the Phoenix could charge the battery. perpetuum mobile … ? And when the AC input is gone, this means that for roughly one second the Phoenix will also charge form the battery. But this is something I can live with easily.

And if we really had a very low power AC input (of e.g. 1A) we can still unplug the remote input and force the Phoenix not to charge. Or manually switch the MultiPlus to Charger mode only.

For us this is a usable solution without the need for multiple configuration changes nor the presence of a GX device.

Electric Installation in our Toyota HiAce 1994

Now, that we got our Toyota HiAce we thought it might be a good idea to add more power to the vehicle: in form of an 8s EVE LF280K LiFePO4 battery and a Victron MultiPlus Compact 24/1600/40-16 inverter/charger. In the following, we describe our setup and the reason why we built it like this.

The Requirements

  1. The sustained output power of the inverter must be over 1'200W.
  2. Charging via AC via EVSE or generator must be possible.
  3. Charging via alternator must be possible (but is not the norm).
  4. Charging of 60% of the battery (from 20% – 80%) via AC should take less than 180min.
  5. The installation should use the minimum amount of space possible.
  6. We should be able to use our existing Eve LF280K cells, thus limiting the overall current to 140A.
  7. As the vehicle will not have a diesel heater, it should be possible to run a 150W infrared heater for at least 3 * (4+2)h = 18h (^= 2'700Wh).
  8. In addition, the battery should be able to run a refrigerator with an average power consumption of 50W for at least 72h ^= 3'600Wh (next to other power consumption).

Design Considerations

  • With a maximum current of 140A and a cable run length of 1.5m, we should plan with a cross section of at least 35mm2.
  • Basically, with Eve LF280K cells we have three choices regarding the battery size:
    • 1* 4s (“12V”) Configuration
      4 * 3.2V * 280Ah = 3'584Wh
      This would lead to a required nominal AC charge power of at least 716.8W/h and a charge current of at least 56A/h.
    • 2* 4s (“12V”) Configuration
      2* 4 * 3.2V * 280Ah = 7'168Wh
      This would lead to a required nominal AC charge power of at least 1'433.6W/h and a charge current of at least 112A/h.
    • 1* 8s (“24V”) Configuration
      8 * 3.2V * 280Ah = 7'168Wh
      This would lead to a required nominal AC charge power of at least 1'433.6W/h and a charge current of at least 56A/h.
  • The Victron MultiPlus Compact xx/1600VA inverter/charger provides enough sustained power output (while being smaller than the non-Compact edition). Depending on the voltage of the battery, this will slightly impact the amount of charge current.
  • To charge the battery via the alternator we would need a DC/DC converter that depends on the battery configuration as well (either 12-12 or 12-24). So, let’s have a look at the battery first.

1* 4s (“12V”) Configuration

The smallest, lightest and cheapest configuration. But capacity requirements regarding the fridge are only fulfilled, if there are no other loads. In addition, the discharge current is relatively high (scratching the maximum discharge rate of 0.5C).

2* 4s (“12V”) Configuration

More complex setup, as each battery needs a separate BMS, which leads to the need of an aggregator for both batteries to correctly report SoC and calculate CCL and DCL. In addition, more cabling and fusing is required (and probably to a large bus bar). Comes with the advantage of having a redundant battery in case a single battery fails. Most expensive configuration.

1* 8s (“24V”) Configuration

Custom battery build needed, as there is not enough space for a typical 2 * 4 cells setup behind he seats. But, only a single BMS and thus less wiring is needed. Comes with a slight disadvantage of not having native 12V from the battery. This is actually not an isse, as all our DC devices also accept 24V. Cells can better balance voltage differences across a single 8s bank.

The Setup

In the end, I decided for the 8s configuration, due to less complexity. Splitting the 8s configuration across two cell blocks seemed to be an acceptable compromise.

As a regular MultiPlus 24/1600/40-16 would not fulfill my AC charge requirements, I had to decide to either add a second MultiPlus or to add a dedicated charger. I opted for a Phoenix Smart IP43 Charger 24/25 instead of a second MultiPlus. The MultiPlus in parallel would always consume 10W though most of the time I would not need the output power. Whereas, the Phoenix would only need power, when connected to AC. And reconfiguring the MultiPlus every time I charge was not an option for me. And yes, I lose redundancy – but also save some money (Phoenix is much cheaper). So, in the end the nominal charge power is 40A + 25A = 65A, which lets me charge at 1'560W reaching 60% within 165min.

The HiAce comes with a 70A alternator, so I chose a Orion-Tr Smart 12/24-15 DC-DC Charger. With this charger, I could run the engine in standby and still have the car heater running. And this is probably the predominant use case (if charging via alternator at all).

For the DC bus bar I went for a Victron Lynx Distributor, so I could use and install MEGA fuses. Having a 1’000A bus bar seems certainly overkill, but a separate bus bar and fuse box that accepts 35mm2 cable and MEGA fuses would be not be much smaller.

I changed the existing AC inlet of the HiAce to Neutrik PowerCON True1 TOP (congrats to the marketing department, I am still amazed how this name rolls of the tongue) and installed 2 Siemens compact 16A C RCBOs (external AC in, internal AC out). I am aware that theoretically I could support more than 16A on the internal AC out (via PowerAssist). If ever needed, I can replace the RCBO with a 20A version.

I added a VE.Bus Smart Dongle to the MultiPlus and opted against a complete (Raspberry-based) GX installation. The reason, I keep a USB MK3 with me anyway (in case I need to reconfigure the MultiPlus) and still have (Bluetooth) access to the most important settings and information of the MultiPlus. With the GX, I would to be running a WiFi hotspot (and consuming more energy as well). The disadvanage of not being able to use DVCC with information from the BMS is clear to me and accepted.

I selected a B2A8S20P JK-BMS that has an integrated 2A balancer and an RS485, CAN and heat port. In case, I ever add a GX device, I am still able to connect them and use DVCC.

The Specs

  • Nominal power (“capacity”)
    8 * 3.2V * 280Ah = 7'168Wh
  • Maximum discharge power 1’600VA (1'280W, capped by the inverter)
    with a maximum current of 80A/63A/55A (at 2.5V/3.2V/3.65V)
  • Maximum AC charge power 1'560W
  • AC Charging from 20% – 80% in 165min
  • Maximum DC charge power 360W
  • MultiPlus self-power consumption 10W

The Build

As mentioned before, due to space constraints I had to split the battery in 2 parts (with each having 4 cells). Instead of using utz RAKO boxes I used 12mm (sanded) plywood which I did not screw together but tied down with a banding/tensioning tool and a ratchet strap. With this setup, I can easily access und disassemble the cells if needed, while still having a sturdy case. Both cell blocks are connected with a (blue) Anderson SB175 connector.

The BMS itself is mounted to the side of one of the cases (I took extra care to use short screws, in order not to drill into the cell casing). I used M6 Weidmüller 35mm2 90° angled compression cable lug to get the wire away from the BMS and into the bus bar. All other compression cable lugs are DIN 46235 from Klauke (M6 35mm2 on the cells, and M8 16mm2/35mm2 on the bus bar).

The AC and DC wires are all Eland H07RN-F (except for the last two points):

  • Charger to bus bar, battery to bus bar: 35mm2
  • Cell block to cell block: 2 * 35mm2
  • Alternator to DC-DC converter, DC-DC converter to bus bar: 16mm2
  • External AC in to RCBO, RCBO to inverter/charger (both directions), RCBO to internal AC out: 3G2.5mm2
  • For the balancer cables on the cell blocks I used WAGO 221 inline splicing connectors with levers and bullet connectors with 2.5mm2 wire and M6 ring terminals.
  • For the connection of the Inverter/charger to the bus bar, I used the Victron installed 25mm2 welding cables.

Images

The installation is barely visible behind the seats
View from the back with preliminary wiring
Connection of cell blocks with SB175 connectors, cell block 2 and DC-DC converter
Lynx Distributor with cell block 1
Inverter/charger with space for second charger and cell block 2 (left)

Note: the Phoenix charger is not visible on the images, as I am still waiting for it to be delivered.

Charging via EVSE

Conclusion

We now have more than 7'000Wh of additional energy without losing any storage space for roughly 2'850 CHF/2’500 GBP (parts without labour). We can survive an extended weekend of 72h without recharging while still being able to enjoy amenities as using a coffee machine, heating and refrigerator. In case of longer periods of usage, we can recharge at any EVSE, or via shore power. And in emergencies, we can also charge via our Honda EU10i or via the alternator of the vehicle.

The battery is placed directly over the engine which helps in cold weather conditions to easily warm up the batteries to a chargeable level.

The installation can be monitored via Bluetooth (Victron Connect and JK-BMS app).

ESP32 with PlatformIO, C++, Unity and ESPIDF

As a follow up to my post about ESP32 with PlatformIO and Arduino, in this post I present how to use PlatformIO with the Espressif IDF (or ESPIDF, for short) in conjunction with C++ and Unity as a UnitTesting framework.

It proved to be much more difficult to get this running than with the Arduino framework.

Here are our requirements for development:

  1. Support (hardware and framework independent) unit tests to be run on the local dev machine (aka env:native).
  2. Support hardware and framework specific unit tests to be run on the actual microcontroller.

Here are some similarities and differences between ESPIDF and Arduino:

  • Again, the native environment will be compiled via SYS2/Mingw64 whereas the microcontroller environments are compiled by the compilers provided by the PlatformIO toolchain.
  • ESPIDF uses app_main() instead of the setup()/loop() construct in Arduino.
  • ESPIDF by default creates a main.c instead of a main.cpp file. We therefore have to use extern "C" { } to unmangle the symbols in our code.
  • For whatever reason the use of #ifdef __cpluscplus always evaluated to false and was therefore not usable. Thus, I used extern "C" unconditionally in the code.
  • To detect the ESPIDF framework, I used the ESP_PLATFORM symbol (instead of the ARDUINO symbol).
  • All framework dependent cpp and h lib files are guarded with #if defined(ESP_PLATFORM).
  • All test code (test_embedded and test_native) has to be surrounded with extern "C" as well (only the code and certinaly not the #includes).
  • Classes and code in lib_dir should not be surrounded with extern "C".
  • Also, I pretty much moved all the code to lib_dir, so the main.cpp is essentially only a stub.
  • We have to manually enable exceptions to support throw etc via build_flags: -fexceptions.
  • (not unit test related) Reading out GPIO to get the state of an LED always returns 0.

The final result can be found here.

Summary

Again, it is quite quirky to setup the development environment. Plus, I could not find a single example out in the wild (PlatformIO in conjunction with C++, Unity with embedded and native testing, ESPIDF).

In the end, I now have a working environment where I can hopefully do what I want to do: sending and receiving CAN messages via the TWAI interface. We will find out …

Reverse engineering the BYD Battery-Box Premium LVS CAN Protocol for Victron Venus OS

On my goal, to build a battery with a Venus OS compatible CAN interface I decided to have a look at he BYD CAN protocol – for several reasons:

  1. It is supported with Victron and Venus OS.
  2. I happen to have a BYD Battery-Box Premium LVS dual battery system.
  3. I heard mixed information about the Pylontech CAN protocol implementation.

So, I got myself a Kvaeser Memorator Light, in order to be able to sniff the CAN traffic between a Venus OS and the BYD BMS. For whatever reason, I did not get it to work, so I ended up with candump – which proved to be more that sufficient for what I needed.

Note: of course, before I started reverse engineering the protocol, I made some effort to find resources and someone who might have already done that – but no luck. However, there were some fragments regarding HVS systems. But they did not seem to be compatible with the LVS implementation.

If you are interested in the result, you can head right here. Otherwise, stay with me and I explain my approach to correlate the identifiers and data pieces.

  1. First, I just started candump to check the general message flow and to see some recurring patterns (working/normal operation, UseCase A).
  2. I then verified that the communication (which runs at 500kb/s) only consists of 11bit identifiers and no FD frames.
  3. I then identified the several message ids based on sender (TX, Venus OS) and receiver (RX, BYD).
  4. I then monitored the message flow, when I disconnected the BYB BMS temporarily (UseCase B).
  5. And then I monitored the message flow, when there was no BYD BMS present at start and then powered it on (UseCase C).
  6. Have alarms and warnings being sent by the BYD BMS (UseCase D). (see note below)

Things to consider:

  1. What are the units of the data being sent (e.g. temperature came in Kelvin/K)?
  2. What is the byte ordering (e.g for WORDs expect the low byte first and then the high byte)?
  3. Is there a scaling on the data being sent (e.g. 1/10mV)?
  4. Is information distributed over different messages? Or does one message have a special meaning in correlation to another message? (e.g. cell voltage and temperature)

For most of the parts, I *knew* what data to expect or to look for. I just looked at the BMS device inside the Venus OS and looked for data that matched the information shown on the GUI.

In the end, I identified most of the messages. For alarms and events, I will verify them once I have a working prototype on my ESP32 by simulating and sending them to Venus OS. [Edit: Alarms and Warnings are now identified and described. Events seem to be not supported. With 17 frames/messages I can now setup a complete BYD battery simulation towards a Venus OS.]

Here is a Summary: BYD Battery-Box Premium LVS CAN Protocol. There you find also some image of Venus OS with the correspnding information as shown on the GUI.

Hope you find this useful.