I would like to know what’s going on inside the BMS if it’s working or not. What I would love to see is the BMS & 2 ESCs on one PCB in a box.
I’d rather have the BMS housed with the battery like in most builds and prebuilt boards.
A Dual ESC PCB can easily be done. All you need is to attach the two PCBs to one piece of acrylic or something either next to each other or on top of each other.
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Welcome to the forum @raphaelchang! Great to see these projects take shape. Looking forward to trying them both out when they are ready!
Good luck at MIT and hope to see you on here when time permits!
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would be good to have liion support on that bms - that´s what most people use here 
Nice looking bms you got there.
Welcome to the community!
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From a BMS perspective I think li-ion and li-po should be pretty much the same, so I think this would already work just fine with li-ion packs as well. Can anyone confirm that or am I just spouting lies in my excitement? 
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Lipo have a higher low cutoff than lion so would require some adjustments if possible maybe with small surface mounted push button.
they are both rated at 4.2V per cell - not sure what the higher cut-off is you are talking about.
Also, it would be great to bring out a couple of GPIO’s so we can add native deadman and headlight functionality.
Lol edited it mean a higher low voltage cutoff.
Yeah, INSTANT NEEEEEEEEEEEEEEEEEDDDDDDDDDDDDDDDDD
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Thanks everyone for the welcomes! The BMS will support lithium ion (LiPo in particular) batteries. It does have a higher low voltage cutoff (and higher voltage in general) compared to LiFePo4 so it will be a configuration option in the GUI. I’m thinking of doing something like “auto-detect” where you can just plug in the balance connector and the BMS will be able to determine the battery type and number of cells by looking at the voltages at the balance connector.
There are two GPIOs brought out right now, in addition to 3.3V and 5V power for lights, LEDs, buzzers, etc. The GPIOs also support I2C and UART as well as WS2812 driving.
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Can u make a program to send voltages to ur phone? There’s so many complications with an automated bms, if u can just send all the voltages to ur phone u can simply become the bms. That’s what I’d rather do. As long as there’s a low voltage cut-off for the pack.
With a Bluetooth add-on that could be possible. The BMS also balances and protects against over-current and over-charging though, which you can’t really do from a phone. I agree that having an app to monitor the state of charge and other battery stats would be nice though.
thats awesome! Also really cool if people like to use some uncommon packs like 7s or 9s, if the bms is auto detecting
My 2p - create a tip jar for folks to send you cash. I know quite a few here would. Then it becomes easier to spend time on something you clearly enjoy doing. Could end up a product / license for you in the end.
Awesome work man!
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All this excitement made me realize I should post updates on here more often so here goes.
Just finished routing some changes for the next iteration of the BMS, which has slightly higher balance current and an added buzzer. I’ve sent out the first version to OSHPark, so they should be here in a week (can’t wait!). I’m liking the compact size of this board, 3.25 inches wide without the mounting hole tabs which add ~0.2 inches to each side, and 1 inch tall. I think it’ll fit nicely with most battery pack layouts. The short height might even allow it to be mounted sideways on the side of a battery.
Here’s the current layout of the board (with pretty CAD models):
@oneafrikan Thanks for the advice! I will definitely consider. College student budgets don’t work too well with such an expensive hobby 
Now while I’m waiting for the boards, time to go back to firmware development for the ESC…
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I’m almost done with my build but my BMS seems to be DOA. I would love a BMS in this form factor, good luck!