 So, since we are recording, we're already going to start. The replay is going to be available for you if you've just registered as well. So, let's get started. First of all, hi and welcome to navigating the open source battery management system. My name is Anna, and I work for the N-Axis Foundation. What we do is we fund and support open innovation within the energy access sector. And today, together with Libra Solar, we've organized this conversation to broaden the understanding of how open source innovations can positively impact your business, as well as teach you how to get started with navigating and using open source materials. And in the next hour or so, you will hear from Martin Jaeger. He is the lead engineer at Libra Solar, and he is also the developer of the open source battery management system. And Libra Solar's mission is to help provide energy access for everyone, also to reclaim the energy supply using affordable renewable energy solutions. And that is all based on open source hardware as well. And then I'm also very happy to introduce our CEO, Vivian Barnier. He will talk to Martin about his experience with developing a BMS. And Martin will also show you how to get started with navigating all of the open source materials that you will be using when you integrate the BMS yourself. And at the end, everyone who is attending, you will get the opportunity to have any of the questions that come up during this event answered by Martin and Vivian. So I very strongly encourage you to keep sending in those questions through using the chat feature, as well as you can drop your name and what you do as well. And I am now excitedly handing it over to Vivian, who will now give you a short presentation on N-Axis and how open source projects impact the energy access sector. So the floor is all yours, Vivian. Thank you, Anna, for this nice introduction to today's webinar. And hello and welcome also from my side to all participants. I will short a few words about myself. Before joining the N-Axis Foundation to lead its honest mission to push open source innovations in the energy access sector, I worked in the private sector for the energy access, mainly on mini-grids, on pretty much every aspect from developing, implementing, operating mini-grids and providing consultancy service to all kinds of stakeholders from private companies to donors and public institutions and regulators. And today I'm excited to use this experience to push more open source into the sector because working in the private sector, I noticed why we need open innovations. And let me explain you a bit more about the mission we work on at N-Axis. As I guess most of the participants here now, electrifying rural areas with sustainable and affordable energy, those very important points, come with a lot of challenges and for that reason requires innovation and new approaches to overcome these challenges. So energy access organizations, like the ones you're possibly running, require to develop innovations to contest these challenges that you encounter, which makes a lot of sense. However, from our experience and my personal experience as well, a lot of time these energy access organizations end up reinventing the wheel instead of focusing on reaching more end customers. This means you come up with a challenge and say, oh, I need a solution for that, develop a solution, and then by the end you possibly notice actually that's a challenge that most of the other companies I'm working with or which are around me are encountering as well. And the solution I came up with is pretty similar or even the same, even though I used mostly donor money, often from the same donor to come up with the same solution. So we believe these basic solutions that are required to actually come to the end customers should be developed in a more open source way to actually allow sharing and vital development of the sector. So what do we do about that? We promote and support the development of open source innovations in energy access and support and promote the adoption of these for a broader standardization of tools used in the energy access sector. We do these to build an equitable and fair ecosystem where more local companies can participate in universal access to energy because we believe the basic tools to work through electrification don't need to have any IP of it. We believe companies need IP to develop their business, to have their USP. However, a lot of the basic tasks that need to be done can be based on open source technology solutions and business models which are available or still have to be developed. And these will allow more companies to participate on this goal. So what are the concrete steps that we do about it? We support, we curate and we promote. In our support what we do is we identify technology and tools that are missing in the sector, that the energy access sector is not having today but there are challenges which would need these tools and then we support and engage and fund the development of these innovations and push the broad adoption in the sector of these open source innovations. As a second work what we do is curate. We curate and maintain a repository with high quality and easy to use and adopt open innovations and we constantly work on the improvement and maintenance and ease of adoption of these innovations. As the sector evolves also the tools have to evolve and new players come in a new way of adopting and approaching the tools is required so we take over this work. And as a third part of our work we promote that's the reason why you today are here and listening to this webinar. We do promotional activities around open source in general for the energy access sector and particularly on open source innovations which we have funded and supported in their development for the sector. We do this through webinars, articles, podcasts, newsletters etc. And just to give you a short brief on the open innovations that we have in our repository let me start from the very top on the left, I mean left middle there is the open paygo token that I believe most of you might be aware of especially if you work with paygo systems the open paygo token system is an openly available code to encrypt and decrypt tokens for paygo usage in solar arms systems, solar pumps or whatever device is used in the energy access sector then there's the survey toolkit developed by DaVergy which provides energy access companies with a tool to easily assess and survey communities, regions they might want to electrify then there has AirLink developed by SimoSolar which is a relay extension of the internet to allow even for the most remote assets to be connected to an IoT functionality using smartphones as data carriers for data and low energy and low cost Bluetooth technology then there's the battery management system which I won't explain now we also have funded and developed the CCADA modules which include firmware and hardware where we have Wi-Fi and GSM and 4G modules which can be plugged in on existing assets or in future development of assets can be integrated and are completely open source which makes the integration and usage tool any new device you're developing easier then we have an open smart meter to meter AC energy which has been developed by the Nigerian company in Nigeria and has also been produced there already which has a GSM functionality to allow IoT capability and then on the less hardware software side but business model and concept side we have the DWAC initiative the distributed renewable energy certificates initiative which allows decentralized energy companies like some of those listening to us today to participate on the renewable energy certificates markets which were closed or unlocked for them so far because the work of filling out PDF forms to report the energy you have produced is just not viable for the solar home system or even for mini-grid so the DWAC initiative is providing an optimized platform for collecting data on renewable energy production by decentralized energy systems and allows to monetize them and lastly the aggregate business model which is a business model which integrates agricultural pre-batefactoring and processing with energy producing so the company engaged in energy production, energy retail is also engaging in agricultural pre-processing and leveraging on the logistical capacities which already are set up to push both businesses more forward so the agricultural processing needs energy but also needs logistical capacities the mini-grid company has logistical capacities and is providing energy and combining these both is creating a more viable business model so let's come to today's main topic the open battery management system which has been developed and is currently being implemented by LiPoSolar so I will be happy to hand over to Martin Jäger the CEO and lead developer of LiPoSolar to give us a short intro on the open BMS Hello everyone and thanks Silvian for the introduction so we developed this BMS that you see on the screen together with the Annexus Foundation which provided funding for the development and I'm very happy to talk about our experiences during the development and what we learned today with you so first of all you probably want to know what a battery management system is if you don't have that much experience with developing batteries yourself so I'll shortly explain this it is basically the heart of every modern battery so especially if they are based on lithium ion or lithium ion phosphate cells then you will always need a battery management system and the battery management system will protect the battery and at the same time monitor the cells that they are always operated in their correct operating range so the operating range is of course the voltage and the current but also the temperatures where they are allowed to be used in and the battery management system takes care of that and if something goes wrong it would switch off the current and protect the battery cells so that nothing can happen to them and one additional important aspect of the battery management system is that it provides more insights into the battery so it provides data from measurements inside the battery management system so for example the current and the voltages of the individual cells, temperatures and so on and all these functions are integrated into this board and so we have on the left side we've got the high power part where you can connect the thick cables coming from the cells and going to the outside of the battery so the cables going to the cells would come from here and then you see these huge MOSFET switches which can switch off the battery charging or discharging path depending on the conditions the batteries are in also we've got a current measurement with a shunt which is shown here and then we've got some connections which can be integrated into the or used for other components inside the battery pack so normally you would use this component the BMS and then include it into your battery pack product and you would probably have an on off switch or you would have a display or any other communication interfaces to interface with inverters for example and all these interfaces are provided by the BMS and are shown here the one is the on off switch which can put the battery into a deep sleep mode where it hardly consumes any energy and so it can be stored for a long period of time then we've got some communication interfaces shown at the bottom one important one is the CAN bus which is used in lots of automotive applications but also in off grid applications because it's a really reliable protocol and it can be used to connect many batteries in parallel or talk to an inverter or talk to other systems in the system then we've got the I2C protocol for more user interface stuff like a display that could be integrated into the battery pack and we've got a USB connection to update the firmware and you add a serial interface for different purposes like GSN modules which are talking on serial interface or you could use it for modbus connections with RS4.5 transceiver attached to it so there's really lots of possibilities how to connect the BMS and for that of course you also need to be flexible on the firmware side so I will talk about that later coming back to the more hardware specifications so our BMS can handle up to 16 cells in series and those cells would be connected at the right side and each cell is monitored on its own and with 16 cells in series you can reach a pack voltage of 48 volts nominal with lithium iron phosphates and that's really the most typical use case for slightly higher power applications but not high voltage so it's still safe to touch but it provides sufficient amount of power to be able to use it in mini grid applications for example and the other maximum current is 100 amps depending on the amount of heat sink you put behind the BMS if you don't need that amount of current you can also reduce the components on the board easily and make the BMS a little bit cheaper you can connect basically any type of cells for example the nickel cobalt manganese cells which are often used in laptops and so on and cars because they have very high energy density but they are also a little bit more expensive so for off grid applications the most typical cell would probably be the lithium iron phosphates cell LFP but it's also possible to connect any newer technologies because the parameters for the cells are flexibly configurable and as I already mentioned we've got lots of different communication interfaces the one that I didn't mention yet is Bluetooth and Wi-Fi these are provided by the ESP32C3 chip you see at the bottom and that's also the microcontroller that provides all these interfaces that's basically the introduction to the BMS itself great, thank you Martin quite impressive also I had it in my hand already and also seeing it again here that you have achieved this work in such short time with this limited resources and your small team but impressed on the result I would like to make you some questions on the BMS so it would be interesting to learn a bit more for me and for the participants on what makes this open source battery management system so different from proprietary versions of a BMS and which problems have you encountered or have been reported to you from people using or wanting to use a BMS which is proprietary so I know you have prepared some information on that so maybe you could enlighten us a bit more on this aspect sure, so I think one of the key aspects is really the open source nature of the BMS because if something is open source you can change it and customize it as you want because you can either tune the hardware tune the software which is usually more easy and adopt it to your application as you need it and with proprietary designs usually you have one dedicated set of functions and if it doesn't really suit your application for example communication protocols there are so many communication protocols out there some batteries talk with proprietary protocols same for inverters and so on and if your communication protocol doesn't work for the BMS then they can't work with each other you can with an open BMS you can just change the firmware and then you get these functions so our BMS was designed with KiCat which is an open source software as well which is also very important because it lowers the barrier to adoption and usage of the BMS so if it was designed with a software like I don't want to name any but there are some softwares out there used in the industry which cost tens of thousands of euros then the open source aspect is useless because you need a license for that expensive program but with KiCat you get professional great PCB design software for free so that's what we use for the designs then for the firmware we've chosen to take Zephyr Arthos as the basis for our application development and the Zephyr project is part of the Linux foundation so it's also backed by a huge open source community and that's really one of the main advantages that it has lots of features already built in so if you want to change to a different communication protocol it's already there, you just need to kind of enable it and then you can use it with the BMS and it's also continuously improved and actively developed and for the communication we're using some open communication protocols partly developed at Libre Solar I will show that later on but you can, as mentioned, easily adopt it to whatever you need in your application one other aspect of open source versus proprietary is also the cost of the product so of course if you want to use the BMS inside your battery pack you don't need to pay for the development anymore or only need to pay for the additional development you need for customization and that's especially for small companies a very important aspect so you can develop your product around the BMS and one other aspect in proprietary designs I have encountered is that sometimes you don't even know what the features of the BMS are or how much current you can draw through the BMS because there's a data sheet that states just very rough numbers and you can't really judge if that's really true or the communication protocol is not properly defined and you have to try to reverse engineer it and try to understand it and in our case everything is open even if it's not well documented on a higher level you can just look into the code and you'll see how it works Yeah, great Martin, great feedback that's true, even though you don't find the information in the first place you have the chance to look up everything you want to look up even though I see you have well documented but generally about open source it might not be the case but you always have the chance to get the information you want and are not in a hotline for hours to find out some information from a customer which is possibly not even existing your point on the current is actually already a question for later in the Q&A but we will answer it so let's move to another point which is I think very interesting also the potential of open source in general and what we as an axis also stand for and want to push and I discussed the example of the open smart meter which is locally developed in Nigeria and has been manufactured there already so how is the possibility of manufacturing the PCPA of the BMS locally so what equipment is required which machinery besides the parts of course to source on somewhere but which machinery which equipment would the lab production facility need to be able to produce the BMS as it is designed right now yeah so we tried to design the BMS such that it can still be manually assembled as you have seen it's containing almost entirely just SMD parts so surface mount devices and not the older through-hole technology but the size of the parts is still not the smallest you can see like smart phones and so on and yeah for lots of the parts you can't even get these through-hole components get them in packages with through-hole components so you have to use SMD parts and soldering them manually is still possible so either you can use tweezers or you can have access to a manual pick and place machine it becomes a little bit more easy or you can have a look into this picture which is the pick and place machine in our FabLab which is also a manual one it has a small suction nozzle and with that you can place the parts on the PCB it takes a while but it's possible to do it by hand and yeah also for rework and so on you can still do that by hand what you need as material is you need the PCB of course and the parts and you will need a stencil to apply the solder paste the solder paste can be seen in the pictures it's the small gray cream on the golden pads and these are used to connect the parts with the PCB and the process is that you apply the solder paste with the stencil then you place the parts and afterwards you put the whole assembly into a reflow oven and then it a temperature profile of up to 250 degrees is applied and then the PCB is ready these reflow ovens are also not very expensive so the one we use cost 250 euros so it is doable on a small scale but of course there are lots of parts and you don't want to produce hundreds of balls this way so it would be more recommend for prototyping and then afterwards you would use an automatic pick and place machine and some more professional equipment during the design phase one little aspect you can see in this picture we were originally planning to use press fit connectors which can handle quite high currents but we finally decided to go for just SMD connectors because it makes the assembly to the heat sink easier and it reduces one of the manufacturing steps and you need one machine less but for these connectors they have quite a huge thermal mass so the process of soldering has to be this has to be considered in the soldering process so that the solder is really getting melt properly okay great, thank you for this insights, very helpful and detailed, just a very quick one for the PCB I mean you need the PCB printing facility where you can order this but it's not like anything very particular about your PCB design which like would ever like manufacturing that can produce PCBs could produce your PCB well yeah it's a good question so we are talking about power electronics here and you need thick copper layers in the PCB so the usually very cheap manufacturers from China they may not offer the correct copper thickness so we're currently using 70 micrometers and often you get only 35 micrometers or less and then it would not be possible or only for much lower current good detail thank you for that and just another quick one, I remember I mean in the process we work with you on the development that there were some problems about sourcing pieces for the development which you encountered which possibly people working in industry are also aware of that sourcing lately has been quite challenging so if you could say a few words about the sourcing and how you have mitigated and what does that mean for the replicability of the BMS in the in the near or long term for the future yeah thank you yeah that's a tricky topic indeed so when we started the project we were really like oh there's this chip crisis are we getting something to work at all and then we decided on some chips and ordered enough chips for example this BQ chip from Texas Instruments which is the core cell monitoring chip yeah we ordered a few of them so that we have them in stock and then designed the PCB so that you don't get into the situation that you've got finished design and don't get the chips yeah the situation has relaxed a little bit but still some of the chips like this BQ chip are not readily available everywhere not with the the big distributors like Digikey and Mauser and you can only get them at some Chinese suppliers on AliExpress for example so that's still tricky but it looks like it's gonna relax a bit more in the future two other components which were tricky were the switch mode power supply IC which is the component that translates the higher battery voltage into the voltage required by the microcontroller and that's a component that's in every electronic equipment but yeah so they were also out of stock the one we are currently using is in stock again and also there's a one which we couldn't get when we designed the PCB that one is also in stock again and for MOSFETS the original Infineon one that we planned is still not in stock but we got some replacements and always if we had replacements we noted them in the PCB in the schematic so you can have a look and see okay if this one is not available maybe you have to reduce your current a little bit but then you can still manufacture the board in parts yeah at the very beginning we thought that we could build a board with several different options of microcontrollers because they were most critical but yeah they needed a lot of additional space and we finally decided that this is maybe not the way to go because maybe you even have the situation where both of these microcontrollers are not available so the idea now would be if the microcontroller is not available then you can redesign your board but because we are using the Zephyr operating system it's just a few lines of code literally so you just need to change the board definition and then you can use a different microcontroller for the BMS so that makes it easy and yeah avoids too much effort. Great and then as the last one I would like to know what for you was the most helpful besides the funding that NXS provided obviously to make your work on this possible but besides the funding that NXS provides what other support or help of the services or the package that NXS provides you've been appreciated and has been helpful for you yeah would be good if you share a bit with us not to hear it again but also with the participants of this work yeah so there are several aspects where I got help and yeah where we really worked together with the NXS foundation which was really a great experience so one of them was technical discussions in our regular meetings so at the very beginning with Fabio and now also with you we had some discussions about parts and design considerations and so on also on the deep technical level then on the non-technical level I really appreciated that NXS has experience with promotion of the BMS and has a huge network of other people and companies in the energy access sector and yeah this is sometimes something that I don't take care of too much I'm focused on the technical part and then the promotion of the ideas so it's not worth anything if no one knows it so that's really one of the parts that NXS provided help with great so yeah we are happy to hear that and this is obviously part of our work we want our companies we work with to profit from our outreach that we have in the sector from our promotional activities that we provide from our network we have within the energy access sector so that your innovations get the attention that they need to get because there's great stuff that you are doing and that others are doing that needs to be seen in the sector so it can be used and adopted properly so thank you for these more detailed insights on some aspects of the BMS and how we have been able to support your process and I would now head over to you Martin to provide us with a very like brief introduction how to get started with the BMS if somebody wants actually to say okay I want this this is great I want to test it or I want to produce it and manage my battery with this open BMS how could you guide us a bit how to approach this in the easiest way sure so there's a lot of material actually which you need to build and use the BMS and probably the best starting point is really the in excess website where you click on the materials button at the top and then you can click on the battery management system and get to this page which provides a summary of all the links that are required for the BMS and the most important ones are the link to the firmware repository and to the hardware repository these are all hosted on github so you can post your issues or send pull requests and the page for the BMS hardware for example looks like this it provides a really draft overview of what the BMS is and contains lots of links to the documents required to understand the BMS and get started with it so one is the PDF file of the schematic there's of course also the native kycat file which you can use but a PDF is easier to access if you just want to have a short look then we've got the bill of materials as a normal CSV file and then interactive bill of materials which I will show in the next slide and a link to the firmware repository and the manual and some mechanical design files as well the user manual which is also linked in the previously shown page contains all the information you need to integrate the battery the BMS into a battery pack for example here it shows where to connect the chargers or the loads where to connect the battery cells in this connector and the temperature sensors and contains lots of other information how to use it then this is this interactive HTML bomb I just mentioned it's an export from the kycat program and it's really useful if you want to build the BMS or also if you want to have what the components on the BMS are so you get this bill of materials at the left side and you can click on those lines and then it shows you it highlights the parts on the right side corresponding to the entry in the list and this really helps for manufacturing and understanding then there is the firmware github repository you can of course look into the source code itself but maybe as a starting point it would be best to look into the render documentation which is linked at the top right corner here and this will bring you to another website which looks like this and it shows the basic features of the BMS firmware it shows how to set up the workspace based on the Zephyr RTOS and also shows you how to flash the firmware and at the very bottom you see the API reference where you can see the different functions and how to call them so that you can get an easier understanding of the firmware and last but not least the communication protocol we are using it's called Thinkset and it is the same protocol that we use for the serial interface and for Bluetooth and it can also easily be integrated into the internet and cloud infrastructure via MQTT it's all documented in the Thinkset.io website and the basic concept is that you send some JSON data from the device or to the device and with this data you can configure the BMS for example you can set different voltage thresholds for over voltage or under voltage and so on and you can read out measurement values basically do everything you need to interact with the BMS and for doing that we also provide an open source mobile app that's developed in Flutter you see the link down below but it's not so this app is still in the in progress it works with and I've only tested this with Android so far but yeah there will come some more advanced features in the future currently it's sufficient to set the threshold and get some voltage measurements and so on but it will be improved in the future yeah that's everything from my side. Thank you Martin you have to say very impressive always when I look at all the work that you've done and how you've done it like the very high quality documentation I mean very high quality battery management system the very high quality documentation of the work you have done which is an essential part for a good open source project so it makes easy to access and understand and actually adopt improve the work that you have done so congratulations for that again which brings us to the Q&A session now where I would be happy to take now the time to answer some of the questions that have been raised during this call in the chat so let me tell you the first question which I have here noted I think by Oskar from Okrasola how is the cell balancing done is it an active or passive yeah and the next one would be a bit related what's the balancing capability in ampere cells okay yeah it's a passive balancing and we actually discussed at the very beginning if we should implement a passive sorry did I say active it's passive balancing okay and we considered implementing an active balancing but really struggled to find a cheap solution for that so there are some chips by linear technologies and Texas Instruments and so on which are so expensive that if you apply them for the 16 cells you almost pay the same price for the whole rest of the BMS just for these chips there are some cheaper Chinese not very well documented parts which we also could not get so we finally decided that we'll stay with passive balancing for now and yeah if you really need active balancing you could put it in between the cell connection so between the BMS and the cell connection and you could put an additional board to have that so as a kind of modular approach and yeah we understand that this is maybe a small drawback if you want to use it for second life applications for example but yeah that was a decision also taking the cost of the design into consideration the balancing current is 100 milliamps maximum that's what the chip provides per cell right per cell yes and it's currently limited to 4 cells at the same time because the chip could get too hot I have not tested if more cells are possible possibly yes it also depends on the ambient temperatures thanks great I think this answers the question quite precisely so there's a follow up question next question also by Oscar what is the surge capability I mean you state like 100 amps continuous but what would be like for a few seconds maximum current yeah I guess 200 amps for 3 seconds should be doable even though I haven't tested it yet also the full 100 amps capability haven't been tested yet we're still so yeah the initial tests were without the heatsink and now I've got a test set up with the heatsink and I got a new test equipment which can go up to 100 amps 120 amps I could test that but not 200 but I think that's not not a problem so the MOSFETs are really they can really handle lots of current but the problem is more how to get rid of the heat over time so 3 seconds should be doable I would say great that's cool and good to know and yeah as you can see we are Martin and Deepa Sola currently like terminating this project and terminating is always complicated with open source projects the ideas that they always go on but yeah it's designed for 100 amps and we are happy if companies are interested in the BMS want to run tests so especially the ones which can be destructive tests to see how much amps we can actually run through the BMS to see where's the limit this is always interesting it's valuable information but comes with some cost because afterwards your BMS isn't usable anymore so let's come to another question that I've noted here what was the raw production cost which achieved for the prototype runs so we are not talking about scale but maybe you can also give some assumptions for scale and maybe also compare with proprietary ones which have similar specs that your open BMS that you are aware of yeah sure so the production cost of the BMS including cables, the temperature sensor and connectors was almost exactly 140 euros with quantity of 25 boards and produced in Germany locally so we really didn't try to lower the cost and we took an assembly company that we knew and have it produced locally I would estimate if you find some cheaper components for example the terminals were quite expensive like 3 euros something per terminal and if you have an integrated solution where for example you already know that the cables are going here or there then you could easily change the BMS design a little bit and maybe lower the wires directly onto the board or have another different solution for the terminals and save a lot of cost and also for a larger quantity obviously cost would go down so I would estimate it can go down to 50 euros depending a little bit on really the current you need the MOSFETs we are using at the moment are from a Chinese flyer called I forgot the name actually they are in the schematic I forgot that the Infinium ones so they are also a huge cost driver but yeah that's the ballpark numbers and in terms of competitor BMS so what I have seen on the market is usually around 400 to 500 euros for BMS systems that are comparable to this one and yeah obviously they need to their production costs yeah so but if you need a BMS inside your battery system and yeah this BMS suits your needs then you could just go ahead and let it be produced for the much lower cost then if you buy one of the shelf one sure this is great and impressive figures I mean still as you said this producing might come with some problems still for some time but yeah once this is figured out this is an impressive price difference actually this like 400 euros you mentioned is for passive balancing so without active balancing or with so this is really also with active and passive with passive so like really the same specs this is yeah impressive so for companies interested in using a BMS saving quite some money on it he might be one which could be interesting for you I have also a question from my side what are the like next steps you would see as the most I mean for sure you have like 100 things in mind that could be improved or changed or whatever but if you could like name two maximum three features or improvements or changes that you could figure be interested or value for for this BMS either as like a second one possibly one with an active balancing just an example or just an improvement or change to the current one which would make it either cheaper or better or whatever two or three features you could imagine it would be a good further development yeah so I would say most important of course is to do a bit more testing with the existing BMS boards we have available and yeah we are also currently testing the board with five other companies from the energy access sector so they are our early adopters and yeah one of those companies is also quite involved in SOH and SOC so state of health and state of charge algorithm development and I think that could be another aspect of improvement so to go ahead on the software side and improve these functions where you can really get into lots of sophisticated details to predict the state of the battery better and that would also be something where people can easily contribute because you don't need any additional hardware development yeah also communication protocols for example if there is a specific inverter that's used commonly in lots of applications then we could add the firmware and add the communication for this inverter to the firmware and then it could be drop in communication and one very important but maybe a little bit utopian goal would be that the BMS would be produced locally in lots of different locations so that it's not produced only in China and then shipped to East Africa for example so that the value addition stays in the countries where the product is used and that's also one of the key aspects of open source in my opinion that this can be achieved I think we pretty much align on that one and it's also part of the mission as a nexus which I mentioned at the very beginning and just to follow up on that one is there what how aware or what is your knowledge about the available manufacturing capabilities locally and sourcing so I mean which infrastructure is there any like changes you would need to the current PCP A design to make it easier to manufacture locally and talking about the whole manufacturing like the PCB and the PCBA or do you think actually it's possible it's just about sourcing because I mean you possibly won't start producing all single parts of it locally this is maybe I don't know is there anything that you're already aware of maybe you could give some insights shortly on this last one because then I think we have soon to close this great webinar yeah I think it's really mainly about sourcing I don't have that much experience with production and let's say East Africa but we talked to one supplier in Rwanda some time ago and yeah they said that sometimes it's difficult to get the parts because of customs requirements and so on and that's one of the tricky parts and yeah of course you need some manufacturing machines but that's all doable I would say yeah and if someone has of the audience has experience I'm also happy to get in contact with people who have interest in producing the BMS or other open source hardware great to hear and I think that Alliance also was our understanding that I mean the manufacturing should not be a problem today in Western or Eastern Africa for this kind of BMS should totally be possible the sourcing of parts or special parts might be the challenge but it's even challenging in Europe today so there's possibly not that's a big difference but a call to everybody listening here today so if you have insights are interested in pushing the local manufacturing also because you're using them maybe in Eastern or you're aimed to use this BMS in these areas happy to reach out to us or Martin and Eva so now both of us and to see what we can do about this aspect because we would love driving using this open source approach to driving the local production yeah driving the costs down for everybody I think with that we can come to an end of this webinar thank you Martin one for the development of this great open battery management system and for being available for our questions today and the walkthrough to how to get started I hope it was helpful to potential adopters and lastly I want to thank you also the audience to be here today for our team at the Nexus for organizing and supporting us and especially to Anna for this nice introduction and setting up this webinar and as a last point please be aware that we have an adoption help program that means we don't only fund new innovations as we've done with the open source battery management system for Martin and we also have our head of product adoption who takes care if you need any particular help in adopting any open innovation for example the open battery management system or any else of our materials that you find of our home page and which I have introduced at the beginning of this webinar feel free to reach us to help at nexus.org and we will be happy to see how we can help and organize further steps that might be necessary to facilitate the adoption of any of the open source innovations that you find in our repository so thank you for attending and have a great day and soon a great weekend just one day left to go so bye bye