#351 10 Battery Power Boards for Raspberries and ESPs. Start of “SuperPower” project

which battery-operated power supply is best for our project in this video i have 10 boards for the raspberry pi as well as for arduino esp and stm32 boards we will compare their features find out the differences and test them because of the test results we will not stop there we will design our own super power branded battery power supply crazy youtubers here is the guy with the swiss accent with a new episode and fresh ideas around sensors and microcontrollers remember if you subscribe you will always sit in the first row which features should an ideal power supply have 3.3 volt output 5 volt usb output usb charging solar charging charging while powering a device replaceable batteries lion or live apo 4 chemistry variable number of batteries battery low voltage protection low voltage signal for mcu a voltmeter ampere meter small self-discharge charge indicator can be used as a shield for a raspberry an esp or even an arduino maybe you can add more features that are essential for you you will get this chance later in the video this is a long list for a particular project some of these features are more important than others this is why we need an overview and this is why i bought these products three single cell modules all with five volts output and two also with 3.3 volts five two cell modules in different configurations one module with a flat lyon battery and one module with four 18650 cells i checked them out and made this table with their features i also added the chips used for the different functions this is important to understand how they work and maybe later for our superpower boards i could have included power banks however most of them cannot be used for our purpose because they switch automatically off at low currents or they stop providing energy while charging so let's start with the building blocks of battery operated power supplies the obvious block is the battery all tested modules use lyon batteries with a nominal voltage of 3.7 volts all but one use replaceable 18650 or the smaller 16340 batteries i like this concept because you can choose your favorite battery type and you can replace a defective battery without problems and you will get this format also in the future to add capacity some of the boards at cells in parallel like that you omit the need for balancing and you decide how many batteries you want to insert all run also with a single cell the batteries have to be charged and protected from overcharging the most popular ic for this function is the tp4056 it is made for 5 volt usb as input but in video number 155 it was also very good with six volt solar panels these chips all have the needed stuff to give lyon batteries a long life like maximum current and over voltage protection one thing however is not included protection against deep discharge this is very important if you want a long life for your lion cells a standard setup for this function is a dw01 and an 8205 dual mosfet you find all you need to know about that combination if you watch video number 160. they switch the load off if the battery voltage is below a certain level sometimes 3 volts and often 2.4 volts they also protect it against over current so we have the most critical three blocks for a operated device now we need one or two more if we want 3.3 volts we could connect a low dropout regulator or ldo directly to the battery simple and efficient but if your battery voltage goes below around 3.5 volts your output voltage starts to drop this is not a big issue for most mcus like the esp8266 or esp32 they should run on less than 3 volts but raspberry pi's are very picky and need an absolute constant voltage because 5 volts are higher than the battery voltage we need a boost converter all boards with 3.3 volt output connect the ldos to the 5 volt rail and so get a stable 3.3 volts also at low battery levels but it wastes a lot of energy not suitable for low power devices without solar panels for these booster chips we find a wider variety like the fp6298 or the mt-3608 which is interesting because of its high switching frequency this enables the usage of smaller inductors and capacitors if we have a closer look at the ap 2016 we see that many of these specialized chips come from chinese manufacturers and are not well documented for western people sometimes information is hard to find some modules use completely integrated so-called powerbank ics like the ip5306 they contain all critical functions except the 3.3 volt regulator in this spreadsheet we have the data of 10 different boards but how to go on we have to specify the needs of our project a ups for the raspberry pi 4 for example first we need protection circuits for the battery against overcharge and under voltage fortunately all modules provide this functionality good next we set the filter to raspberry and get these two boards both can be mounted below the raspberry pi so you still can mount a cooler on the raspberry very good the maximum current is three ampere and the two batteries can feed a raspberry for more than 10 hours also good and they can be charged while the raspberry pi is running the newer port has in addition to the battery functions a real-time clock and a volt and amper meter the volt and ampere meter unfortunately is mounted at the output and therefore only measures the usb voltage useless for a battery operated raspberry because we need a signal to shut it down before the battery is dead otherwise it crashes and can kill the sd card or lose data so they gave a big chance a way to create a perfect raspberry ups adding a simple voltage detector for a few cents would have been sufficient or at least place the ina-219 between the battery and the booster let's go on to the next use case find a battery for an autonomous esp8266 or esp32 project the esps use deep sleep to extend battery life so we need a very low discharge current when the esp sleeps we filter the self-discharge current and find three boards with around 60 microamperes this current is way too high this is because all these boards first boost the voltage to 5 volts and then reduce it to 3.3 volts beside that this port has no 3.3 volts and this only provides 3.0 volts i have no idea why they choose this voltage so also here we do not find a suitable board such a board has to have a much lower idle current and for sure has to provide 3.3 volts because we want to use a bare bone esp module to save energy and they must not have such fancy push buttons for on off these boards often keep switched off after the battery was discharged a no go for a remote node we want either no switch at all or a simple mechanical one next project let's assume we want to extend the battery life with solar energy then we need the same specifications as before plus a solar charger which can accept at least 6 volts from a solar panel better would be more minimum current is not so important because these days solar panels are no more costly a single 18650 cell should be okay for most situations maybe even a 16 340 in areas with lots of sun in winter but we need 3.3 volts so we can use these four modules with 3.3 volts and a tp4056 charging chip the t-beam would also be suitable for solar charging unfortunately it has no 3.3 volt output and its cn 3065 has no significant advantages compared with a simple tp4056 as shown in video number 155 none of them can signal the mcu low battery voltage if the sun was not strong enough a pin to connect a analog input to the battery voltage would not cost a fortune with such a connection the mcu could measure the voltage and either go to sleep or if connected to wi-fi or lora transmit the voltage level from time to time as i do this with my light sensor in node-red i use a telegram bot to alarm me when i have to replace the battery by the way here is another trick for connected sensors my sensors regularly send data each time a packet arrives this timeout node is reset i set its timeout period to at least twice the time between packets from my sensor the timeout node is also connected to a telegram bot which sends me a message when no packets arrive anymore i had an occasional software error in my awning remote control which made that it crashed and did not recover first i used my wife as an alarm system always when the awning did not work she signaled me something is wrong dear mr engineer with a specific undertone of course since then i prefer telegram for that purpose now i found the error and i do no more get alarms not from telegram and not from my wife very good the same principle is used for my lora gateway by the way now it's always up so what about the other boards maybe they fit one of your projects for me they are more or less useless and this is sad so many boards and none really fit the purpose this is why i decided to start a new project together with you my viewers to design the best power modules for our projects you can either work on the specifications or if you are good at pcb design or want to become good work on designing boards i created a discord channel called superpower for the project and a github repository also called superpower and i started with my three use cases an esp32 ports with an esp32 vrom module similar to this mini board but with an 16 340 battery and a similar port that can be powered by a solar panel both have to have all protections plus voltage supervisor which resets the mcu if the voltage is below the minimum voltage of the data sheet and a connection to measure the battery voltage with an analog pin and a raspberry shield for a solar powered raspberry with all protections and a voltage supervisor or an analog to digital converter for measuring battery voltage here i would like two 18650 batteries because the raspberry is power hungry and pins for a gps module to get the exact time these are all use cases with requirements they answer the question what and they have to be finished before we go on to the design phase the how will be answered by the guys who do the design because i want that everybody can get such boards they will be open source their design has to be manufacturable by jlc pcb and all parts should be lcsc parts like that everybody can order fully assembled boards this is important because most of the modern chips are hard for hand soldering i also prepared channels for all building blocks parallel to defining the requirements the designers can start to collect data about the best chips for our designs there is also a section about boards we can learn from like the 10 boards i have here everybody is invited to participate if you want to lead one or more of the projects feel free to contact me summarized there are many boards available to power our projects from a battery 9 of 10 boards in my selection use replaceable 18650 or 16340 lyon batteries none uses liveapo4 which probably is a better technology for 3.3 volt projects all have the following functions lyon charger on the voltage protector and 5 volt boost converter some also have 3.3 volts ldos a few are built as shields either for raspberries or for arduinos one board even has a real-time clock and a voltage and ampere meter unfortunately the meters are at the wrong place and mostly useless the idle current of all boards is way too high for low power deep sleep projects none can read battery voltage nor has a voltage supervisor against low voltage brown outs none of the boards are suitable for my most common needs this is why i started a project to create a perfect board its name is superpower everybody is invited to participate if you want to train yourself as a project manager or if you want some visibility for your future shop feel free to apply for a project leader role we will see where we end and if this time we will get useful products as always you find all the relevant links in the description i hope this video was useful or at least interesting for you if true please consider supporting the channel to secure its future existence thank you bye

Channel: Andreas Spiess

Views: 101,557

Keywords: arduino, arduino project, beginners, diy, do-it-yourself, eevblog, electronics, esp32, esp32 datasheet, esp32 project, esp32 tutorial, esp32 weather station, esp8266, esp8266 datasheet, esp8266 project, greatscott, guide, hack, hobby, how to, iot, lorawan, nodemcu, project, simple, smart home, ttgo, wemos, wifi

Id: -SJbdPvgQnE

Length: 16min 31sec (991 seconds)

Published: Sun Aug 30 2020