FlexiBMS Lite - Flexible Configuration BMS w/ CAN-bus

Have you checked the cell voltage readings from the serial terminal on PC via USB?

Yes, I just did, and I am very confused, because it is reporting the correct voltages. But if I connect it to the Davega, the first 3 p-groups are wrong, like in the picture a few posts up.

Do the serial terminal readings also change when you connect Davega?

What does your wiring look like?

EDIT:

Those look nominal.

pls specify? I have just spliced up the canbus from my two vescs into the BMS.

I just did that and now all readings are normal and correct??? Man I can’t do this anymore. :laughing:

Seems like some intermittent connection or a firmware problem somewhere.

Keep an eye on it and inform if it happens again, because I want to figure out what’s going on.

What are the firmware versions on FlexiBMS and Davega btw?

Tagging @janpom in case he has something to add about the firmware version or something he can think to check.

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The Flexi is on 0.18 and the Davega is on 4.07.

Will do, all these issues are kinda worrying.

Might have been that there is a very lightly bad connection on the 120R resistors on the bottom side or on a leg of the bleed Fet and when you probed them with the multimeter it made better contact, that would explain why it suddenly started to show correct values after the probing.

You could try touch the legs of the bottom cell Fets with the tip of a soldering iron to make sure the contact is good.

I will do this if I get bad readings again.

Thanks for your time and help btw, I’m really appreciating this!! As soon as you’re making more flexis available I will be throwing some money your way. :laughing:

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I’m not aware of any related DAVEGA bug. Since the issue is intermittent, I suspect that Flexi reported incorrect values at the time they showed incorrectly on the DAVEGA. Should you see incorrect values on the DAVEGA while you’re getting correct values in the terminal at the same time please let me know.

+1

Simo’s support in this thread has been outstanding so far, definitely going to be ordering from him once he has stock again, even with the price increase. Gotta support vendors who actually care about their customers. :heart:

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Updated the design a bit: Made the lid a bit thicker and you can now actually use the USB port lmao.

Making a balance connector for the i3-module

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i3, like BMW i3?

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Yes, a BMW i3 battery module

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honestly man, I think you should tell us: with all shit in the world I had to re design board, so new price for 13s-18s version is XXXX euro, I make 35% profit. Take it or leave it, thanks for understanding.

I would respect that and buy it. and many others would as well

Even if he redesigns the board to youse a difrence chip and reprogrammed the software. There’s a global chip shortage happening and he be in the same boat of missing x y and z chips.

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@SimosMCmuffin I was just working with @WavRX on getting BMS communications working with the ILogger, everything seems to work well with the USB connected, but after it is unplugged (still connected to the pack and ILogger) we no longer get communication, am I doing something incorrectly? Thanks!

How is the Ilogger connected to the Lite? CAN-bus?

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Correct, I’ll try $38 here in a minute

Will there be any FlexiBms available for sale soon?

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