Thanks for the update on the 38120 LiFePo4 batteries. Ordered in time before they ran out. Really like the way the design of the boards are going. Hope I can afford some in the future.
I just love diy projects . You are the top man for battery projects . My problem is I live in Portugal .. an effective desert for obtaining anything . I would love to assemble my own solar panel supply and battery storage to supply 5kw or less. I have a 2011 Nissan Leaf which is brilliant and at £6,000 UK Pounds excellent value
instead of cutting them entirely you should have cut, bent and soldered them to the one below. that way you would have got the double current carrying you will have in the next board.
100% agree. By cutting them the way he did, he is completely negating the benefits of the double wires. I'm not sure if that was done by mistake or if he doesn't realize what he did. He will get it right though.
If you want to cut bend and solder thousands of pins, go for it, most of us don’t have that kind of time, we just want to build a battery to use it, it’s not worth all that extra work
@@jehugarcia I was just thinking for those that will be integrating old and new versions of the boards as time goes by, it would be a good way to ensure full future compatibility. I figured you'd modify future versions of the board for native compatibility with these connectors.
Hey Jehu, what Thomas Brekling said but also, glad you are going proper integration in the next version but I was only suggesting for those beta testers who already had bought boards and didn't want to compromise on the amp rating of the cabling. They wont be soldering thousands cause they wont have that many boards yet. Also you do need to solder the pins in the through hole on the next version so in some ways just as much soldering but quite a bit of extra bending. (bet that could be done as a oner in a vice though).Anyway it wasn't a criticism just meant to be a helpful observation. I love the work you are doing. I am all about the plug and play when we get there.
If you're looking to go hot-swappable for scaling, there's a few operational things that you'll want to take into consideration. You'll want to have a visual indicator available on each board so that you can signal the physical location for a "bad" board or indicating a specific board that you want to examine. For your sensing lines, you may want to consider using PCB edge connectors (like PCI cards) as they have lots of mechanical connector options. If you're looking at scale, it may be worthwhile to consider keeping the sensing on the board and use basic ADCs to do voltage sensing and making the data available over a bus like i2c or CAN. It'd also give a path by which to enable/disable the visual indicator mentioned before.
When you were soldering those IDC connectors, hold iron a little bit longer on each pin to avoid cold solder joints. The speed you pulled iron away from some pins is just too fast. The same goes for soldering XT60 connectors. Thanks for the video!
HI @Jehu. The 'Sense' cable and signal path 'noise error' maybe in 100mV or more when connecting battery packs together. I believe the original balancing circuit is designed to sense only 8 batteries, but when stacking up to 2, 3 or 5 the noise may become a factor. The design is good as it is, however i would like to see next pcb update to enhance design by reducing cable, connector and path noise. This enhancement will help with basic common mode noise (CMMR) and help with power supply or battery noise (PSSR). Sometimes they cancel each other out, however other noise may double in power (reflective waves, incident waves, cross talk etc). Since this is DC (0hz) signal sense cable, adding 0.1 uF across each 8x connector pins should attenuate the noise level down < 100mV or more (-60 dB or 1000 times less is the pcb designers goal). Great place to kill as much noise is where the silk screen is located above the header and below the edge of board. The lower the impedance of 8x traces (i.e. less than or 50 ohm impedance) of your sense cable the lower dB noise level... If you want to reduce the noise down to < 100mV per line please add foot pring 0402 or 0805 0.1uF caps. This should not affect pricing quote of the pcb board since you are using existing copper (0$ free). I can't wait you release the kit!
What if instead of the ribbon cable, you made a PCB backplane and all of the boards attached to another board. That would allow it better to slide into a chassis of some sort.
Jesu never has time to answer to our questions. Any expert please answer to me. I just have completed my 7s 18p pcb powerwall. I did not give the connection yet. Where do I need to give the input from my epever controller and where do I have to take my output? Also do I need to connect x60 connectors to every board or just one board enough? Also do I need to have a fuse in the line between controller and powerwall?Thanks for your time to reply to me.
This setup is a really neat idea. I'm thinking each board could have two XT60 connectors, one facing up and one facing down, then you can stack the boards by just plugging the XT60 into the one below. A pair (male/female) of XT60s seems to pretty much match the height of the 18650 battery holder. I imagine you'd have the connectors staggered up the stack of boards. I've made a crude drawing of my idea here: i.imgur.com/LOPJp3B.png - you'd have to solder the boards up in two variants (one with the left connector pointing up, one down), but the boards themselves would be the same.
Hey Mr Garcia I believe all electric car should recharge it self with kinetic energy. I don't think you need to plug your car to charge it. The wheels are a source of power
@@jmonsted I thought about that but it seems such a waste. It should be easy to modify the design and generate another Gerber, but I don't have a clue about PCB design
I’ll buy when you can make a kit for the hobbyists to put together as long as you ship to Australia They will sell like hot cakes I’d say 90AH @ 12v you will sell a crap load of kits
@jehugarcia remove the big battery balance connections off the and go to a smaller 2-4 pin that only carries a data signal of the cell status of that board. you could used the modbus protocol to send the data over two wire or three if you add ground wire. then have a master board that collect all the data to one spot for data logging and info status that could be shown on a display. plus have the master board control the charging and discharging of all the boards. each of the slave board should have there cell balancing circuit with safety cut outs with temperature cut outs as well. that way if one slave board has a cell that goes out of wack can automatically disconnect it self form the rest of the boards until its safe to reconnect. thus keeping power flowing from the other broads. if a cell does not return normal then lets the master board know that service is needed with the cell number and board number. that way the user know what cell needs attention to. i could go on more ways to make safer and easier for the end user. but i hope that helps you in some way.
If you want to exchange(hot swap) modules, will the xt-60 and the ribbon connector both be used or will the ribbon get in the way? Haven't got far enough to test it out myself. Thanks
Hi Jehu, is the current board the final version or are you expecting to update to ver. 3 if so i'll hang off getting your boards. anyway keep up the interesting project.
Fallynn, I was wondering the same thing. Jehu has a lot of lil talents. A lot of people complain about how gabby he is, he’s a good salesman/ hustler. But most of all he is a great video producer, it’s definitely his calling. His choice of background music is always mediative & refreshing.
Just curious, did you have issues with permits and what not with your DIY power wall? how did you get the inspection cleared using the DIY packs? or did you? lol
Why don’t you just redesign the board to use the 16 pin and jump 2 pins together to make a pair running the current through 2 wires it won’t add extra complexity but more amps could be tranfered
i wanna build a 24 v pack .. but i dont wana use a bms .. can i balance my cells by making a conection in parallel of all groops and charge them with 4.2 v .. will this work ?!
@@jehugarcia thanks so much. I m a Nigerian and I m trying to build a portable solar generator, but getting many of the parts needed is so hard, and when one decide to buy from eBay or Amazon, the shipping cost is enough to make one run away.
These boards are progressing well. Would you, could you, get your PCB Artist to design 8S 18650 boards and 7S + 8S boards for 26650? This way, we could progress to using larger capacity cells and also LiFePo4 which has a 10x lifecycle over laptop cells. Many of us have cells of both chemistries and sizes. Any chance?
The proper tool for the ribbon cable connectors is much too expensive. You can put it in a small bench vise. Edit: You can get a cheap tool now for less then 20$
I have about 800 of these that I got for next to nothing. Came out of 12V 100AH (4S88P) battery where BMS had failed killing 25% of cells. Main problem is LiFePO4 18650 batteries are low capacity (1300mAh/cell) but have low internal resistance (50-100 milliohms) so efficiency is high. They can deliver 30A-50A per cell on short circuit.
I like very much what you do. Batteries second life is a bold ecological move, I hope history will keep record of you. I am not ready yet to start on batteries, for the moment I start to accumulate solar panels, some are used grid tied. I plan on switching to off grid with batteries some point down the road especially if things go south in our infrastructures. For the moment a grid is very convenient, cheap and reliable. I am lucky in France to have caught a contract where I can sell for 25 years the power at almost twice the price I pay when I use power. I'm a big fan of SpaceX too ! www.spacexcovers.com
No ware to buy PCB and battery holders.!! I checked every link in the discription The amazon link is for a $70 Power wall box with lid. Thats it no pcbs or battery holders.
Could you do a video on resistance? I watched this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1lJSJWCFQl0.html and he says the BMS is useless due to batteries with different resistant values which has me confused as you've never mentioned it when selecting used laptop cells, as you are the Yoda of batteries I thought I'd ask you, please please as you know I stay up till 5am to catch your live shows I'm a loyal longtime sub. Thanks, Brannen UK Devon, And I'm sorry for watching someone elses channel trust me not as good as yours by a longshot, lol
bad Design, no strain relief, bad Cells would destroy the board because of balance current. Many throuh holeconnections make a lot of resistance, unnessary double sided board ads more cost, and why you dont make all cells on one Board in parallel and stack them up for more voltage, and at the end of each board are more xt60 connectors to add more cells in parallel. each board gets a voltage and balance circut with a monitoring display, a little microcontroller with a can bus interface and an adress selector for remote sensing.
like strain relief , is a bad idea (thought) mabe i use the wrong english word, what i mean. I would never design a product without this, it protects the connections mechanical. And the balance current over these small connections will fail on short time. Even u have designed a one time fuse in the board to adress it 9:27 . But it will destroys the board . I like ur videos but this idea over a easy build batterpack with this boards is not well developed.
Makes think about the meaning of life and how we might be alone as far as intelligent and that we might end up killing everything on Earth because of what we make in our heads...
