BOM updated about diybms HOT 13 OPEN

Hi ArchGalileu, the circuit in Colin's branch is the same as this one - its only the code thats different.

I've not got a farnell list I'm afraid - but most of the components are available from most suppliers. I got mine all through AliExpress for cost reasons.

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hello stuartpittaway

thanks for your fast reply ;)

I will check on alibaba ;)

which list I follow? README or Wiki?

best regards
ArchGalileu

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hello,
i bought mine from readme, where is the wiki and whats the difference?

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My mistake... from README is correct ;)

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Hi Stuart,
I'm ordering parts at the moment, as I'm going to build your BMS for my battery.
I noticed the Drain Resistor is noted for 50 Watts it seems to be huge, did you mean 5 Watts.
From my calculations with 4.2 Volts and a 3R3 resistor the power would be 5.35 Watts so I guess a 7W should be enough ?
For the ADUM1250, do you think the MAX14933 could be a good less expensive substitute ?

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7 Watts will go very very hot... i bought these on aliexpress. https://imguh.com/image/oIHBh

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And i have used ISO1540DR, it is more available in EU and the price is also good. I will post complete schematics etc.. when it will be finished

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I think I will go for a 10 Ohms resistor instead, the maximum will be 1.764 Watts so I guess a 10 Watts wirewound resistor like this one https://fr.farnell.com/multicomp/mcprw0awjw100b00/wirewound-resistor-10-ohm-10w/dp/1737549 should be more than enough.
The BOM in the readme says components cost is around £5.50 but on farnell a 3R3 50 Watts resistor is more than 6£ :-/
Anyway the 10 ohms resistor will be enough for the moment for small balancing.
I ordered ADUM1250s on Aliexpress (x5 times cheaper this is crazy) but I'll also order a MAX14933 to test the difference (it's 1.96€ on farnell vvs 5.47€ for the ADUM1250 and 4.53 for the ISO1540) there is also the SI8600AB taht is 2.94€ I wonder if they would be all be compatible?

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7 Watts will go very very hot...

Agreed it will get hot!

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The BOM in the readme says components cost is around £5.50 but on farnell a 3R3 50 Watts resistor is more than 6£ :-/

Yes although I brought a lot of items from AliExpress - take a look at...

https://www.aliexpress.com/item/Novel-Auto-Car-Vehicle-4Pcs-Professional-50W-Load-Resistor-6ohm-Fix-LED-Bulb-Fast-Hyper-Flash/32907694269.html

or search for "Novel Auto Car Vehicle 4Pcs Professional 50W Load Resistor 6ohm Fix LED Bulb Fast Hyper Flash Turn Signal Light Bulb"

$3 for 4x 50W resistors

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thank you for the infos, I just forked this project and building one now, I'll keep you updated :-)

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I just ordered parts for mine and mixed Mouser and AliExpress parts with boards from www.allpcb.com. I'm sitting at a cost per board for 15 boards of $8 US. I'm sure that can be lower if you take the time to source all parts through AliExpress and eBay sites.

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sourcing parts takes so much time (and it's much less interesting than building or programming)

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