DIYBMS for Lithium Iron Phosphate battery cells (LiFePo4) 280aH

Ok Vassilis I hope to hear from you

Good job!
To solder attiny like a Pro, get a hot plate with temperature about 100-120C, put PCB with solder paste and attiny, wait minute or little longer and then apply hot airgun. On your third PCB you become Pro.)
Here is my setup.


thanks Alex,

still to try this technique, now on my third module and tried the classic solder on first pad, place chip, reflow said first pad and then take it easy and careful with the soldering iron pad by pad. Surprisingly was much more relaxed, not stressful at all and end result definitely the best of the three I’ve tried.

problem now @sato is that controller board not happy to program them as still the two TCAs are missing and I hacked Stuart’s code removing a couple of Halt messages for the thing to boot. Interface comes up, I can get into the program mode, connect module and then fails to program. Will get hold of a usb isp programmer tomorrow and try on Sat again.



fwiw, the code in has some issues with GND copper layout. Will upload a new one soon. Plz don’t use.


ok Vassilis I hope to hear from you

Hey everyone,

I’m sorry that i did not work for that project in the last months.
@vas : totally fine, feel free to use my design.

I will order another 50pcs of my updated v1.01, if I’m happy with that Version i will publish that on my Github page.

I therms of flashing the modules when they are installed, i don’t think that is really necessary. Even if i could reach the boards I would never change a running system if there is no big bug.


Well if you did want to reflash to the 9k6 code, I can confirm that it works fine with this board variant.

thanks @Jau

btw, two points (mainly for others!), EVE changed the footprint of their 280Ah cells and post spacing is NOT 90mm anymore! Obvs will work on the older version of the cells.
second, not sure if you’ve changed the R16 from 4k7 to 2k2 as suggested by stuart. Mine wasn’t, not sure if I’ve used your bom or another one (I was struggling a bit with the JLC)



and a third point :slight_smile:
R21 is 50k whereas stuart’s original was 10k, works fine on my test system with 2modules, not quite sure what it entails.



R21 used in voltage divider of external temperature sensor. It should be exactly 10k or else module will output wrong temperature.

R21 50k … yes … exactly as stated in the post from Fabian at May 2nd.
i fell into that hole and replaced R21 with a 10K since i bought 75mm 10k Thin Film NTCs

i have these boards up and running for 2 months now. They work flawlessly so far.
actively cooled with the above 9x9mm Heatsinks they stay at about 45-50°C with a power dissipation of abot 2.25A each

heiterkiter / macglove

Hey Andrew

may a make the suggestion to put the bus bars on the cells first and then the modules.
In your setup all the current of the battery has to pass through the via of the pcb (and the screw/nut combination).

Had intended to purchase some 15 x 6 x 1 (OD x ID x T) copper washers to put under the nuts to prevent them pulling the track off the board but forgot… Thanks.

fwiw, the code in has some issues with the GND copper layout. Will upload a new one soon. Please do not use it, I can now order the Vassilis modules

correct, that’s why I deleted the post/file.
@sato I’m almost done testing and correcting. Will pack it all up and upload it to JLC to test it.


If you are in the USA I have four of spares and the parts to populate them, $25 plus shipping (USPS Priority).

thanks for the offer Mike, I’m in Greece, customs et al will possibly bite me!
I’d rather get it from someone within the EU although you do have some chips I could use (RS485 fe :slight_smile: )
not in a hurry, cells just left China will be here in a couple of months. May come back to you!


Check my post in the shunt topic, I’ve posted links to the three ICs (excluding ATTiny1614) that would be needed for after JLCPCB assembly.

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I have, hence my mentioning it.
Sadly due to a general dysfunction of normal postal services I cannot buy from ebay/ali anymore as I have to get it via courier service, some don’t.
We shall see, I’m still evaluating what I’m going to gain if I go diyBMS shunt vs the existing Victron one (boat is all victron and BMS will be talking to them via canbus) Currently setting up a raspberry to test comms with venusOS.