Not sure what you are trying to tell me here 
What does all that have to do with my post?
1 Like
Iām working hard on finishing this and am a bit ahead of my predicted timeline, so I might be ready for beta testing by January next year.
2 Likes
did you already calculated costs for this masterpiece?
It looks to be about $105-110 in components right now, but I do plan to sell it so if there are enough orders the price should be around $100 each.
5 Likes
I think your gonna get enough orders
2 Likes
Hi Raphael, Do you plan to release the sources (gerber and firmware) ?
Do you have read the thread? 
There are links to his GITHUB everywhere.
Incredible how fast the development goes @raphaelchang. 
Thumbs up. This will become THE āsmall killer BMSā. Btw the Node Dashboard is not working for me. If I understand it correct I have to go to the battman-dashboard folder in the terminal and then just type ānpm startā. But that is not working for me. I am on OSX like you.
Have installed the latest Node including npm.
1 Like
I had when the thread started. But since Raphael said that he was willing to sell it, he might choose to keep the sources for the final version that he would sell himself. That is commonly done, no judgement of any kind from me.
I have no plans to do that. This is a fully open source project, so I will keep everything up to date in the repos. The only requirement (by the license) is that if anyone modifies it they must make it open source as well.
9 Likes
iĀ“ll probably be down for 2 chang BMS! I hate these big 10s 80A bricks
1 Like
Thumbs up for your open-source development. This is extremely appreciated. I will probably try to build one myself (for the fun of it) and donate for the dev. Great work !
Def buying one if you decide to sell them!
Are you saying that charging at 4A reduces the number of available battery cycles by ~25%?
Raphael helped me solving my problem with the GUI. Thanks for that.
I have done a Mouser list with all the parts available there. I have put exactly the number of pieces needed into the shopping list, also when for example 10 resistors would be cheaper when you need just five. You can find it here. (without engagement) Mouser donāt have the JST jacks/ the sunLED RGB-LED and the very expensive Battery Monitor IC (around 17$) available. (this parts are available on digikey) Donāt forget that the mouser price of 77,6ā¬ are without 19% taxes and a four layer PCB isnāt cheap. Also notice that Raphael is still in the improvement phase, so this calculation I did for me is not matching the final layout.
@raphaelchang Do you think the 50V caps are specced well? I just ask because a full 12s Lipo is 50.4V and we saw with the VESC, that this āvery close or underratedā specs can make problems. When you look the capacity close to the max rated voltage it is a lot lower than the stated capacity. This effect is even bigger because of your 0402 selection.
Are you planing to sell the part sets or the complete build BMS? (So you have a pick and place machine somewhere available, because hand soldering that much 0402 components would be a pain in the a** for several PCBs)
Do you have plans to make that beauty also work together with the VESC from Benjamin Vedder over CAN or is it mostly for your Infinity hardware? Thanks for everything.
Iāve updated the BOM to reflect the latest design. The PCB is around $12 each on OSH Park. The total price will come to around $120 if you decide to assemble it yourself. Also, thereās another store called Arrow Electronics which sells the LTC6803 for only $13, but it is often out of stock. They have a lot of parts that are cheaper than Mouser and Digikey though.
Most of the 50V caps are not used for the battery voltage. The one that is 50V on the battery line is a high quality electrolytic capacitor, which does not have this problem. Thanks for noting this though, I went back and checked all the caps to make sure.
Iām definitely not planning to hand solder all the boards (Iāve almost had enough of that). I am planning to outsource it in bulk to a PCB fab for assembly, and set up a system here for quality testing. The quality will be higher and the cost will be lower this way.
Working with the VESC would require changing his firmware, so I am first getting it to work wth my ESC. The interface is over CAN though, so it should work with either ESC if the firmware is set up. However, once both boards are ready, Iām planning on adding a lot of integrated features that would make the system a lot more advanced if both my BMS and ESC were used together (i.e. simultaneous firmware updates, unified app, etc.).
I have no experience with them. Will check them out. Was thinking they are expensive or was that in the past or has to do with the shipping to europe?
Good to know. I havenāt checked what they are used for, just noticed the 50V in this 0402 package and was thinking it is used for battery voltage. 
That sounds amazing. I know how komplex Field Oriented Control is and the step to sensorless FOC is even a lot bigger, but I think that is needed so eBike and eSkateboards could use it. I think adding a magnetic encoder isnāt possible for most people. But I read on your website that you already are working on sensorless support. Really cool. 
1 Like
It would be better to buy huge amounts from mouser. If you will buy one circuit you will always pay 20-50% more than you would pay for 10 circuits each.
I have updated the qunatity of your shop link @hexakopter to ten and the result ist 564,33. That would be only 56ā¬ for one set instead of 77,60ā¬ Maybe we should make a group buy and get it somewhere assembled.
2 Likes
@DeathCookies Donāt forget the expensive Battery Monitor IC and PCB price. I have done a VESC group buy last time and I can tell you that it is a lot of work and hassle.
Just something I noticed today. You have the IRF7749L1 as your discharge FET. How should that thing be able to let through 120A continuous current when it isnāt cooled? Isnāt something about the half more realistic, so around 60-70A? Or was your number calculated for using two FETs in parallel, but then because of the size you only choose one FET?
1 Like
Correct, I chose to use one FET because of size. A more realistic continuous current is 80-100A (slightly more than an ESC because itās not switching), but that is still enough for most people. Still need to evaluate that though.