Mine is all-in-one. I'd disconnect between batteries and inverter, unless maybe there's a better way?
BMS low-temperature disconnect using Arduino and a relay?
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curiouscarbon
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Is it not easier to use an NO relay to disconnect PV from AIO? I could be missing details
curiouscarbon
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personally i prefer knowing what code is running so i would use arduino, 1,000,000 ways to do it etc..
this microcontroller is 7.5 usd and works great for my ESS hacking
www.adafruit.com
this thermometer is 5 usd and has 0.06 degree C resolution
www.adafruit.com
this 5v step down regulator is 8 usd and can work with up to 50V input.
www.pololu.com
these are the parts i personally would recommend based on having used them in the past.
i do not like the fixed function thermostats because of lack of programmatic configuration and lack of ability to audit code. not bashing just stating my preference. i love customization to application
for context i just recently set up a dumb dc-dc converter with an independent hall effect current sensor on the input and output as well as input and output voltage monitoring to calculate real-time charge power and efficiency. it uses the microcontroller above and a tiny latching relay to control the remote on/off port of the dcdc converter. by writing the code my way i can ensure it functions in my preferred way
the two options for this situation that seem somewhat suitable in my view (which could be wrong) are cut PV input or communicate stop and start command over data bus.
it seems like you are familiar with arduino already so good luck!
this microcontroller is 7.5 usd and works great for my ESS hacking
Adafruit QT Py - SAMD21 Dev Board with STEMMA QT
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with our favorite lil chip, the SAMD21 (as made famous in our GEMMA M0 and Trinket M0 boards).This time it comes with ...
www.adafruit.com
MCP9808 High Accuracy I2C Temperature Sensor Breakout Board
This I2C digital temperature sensor is one of the more accurate/precise we've ever seen, with a typical accuracy of ±0.25°C over the sensor's -40°C to +125°C range ...
www.adafruit.com
Pololu - 5V, 600mA Step-Down Voltage Regulator D36V6F5
Output voltage Typical max current output1 Input voltage range2 5 V 600 mA 5.2 V – 50 V 1 Typical continuous output current at 36 V in. Actual achievable continuous output current is a function of input voltage and is limited by thermal dissipation. See the output current...
www.pololu.com
these are the parts i personally would recommend based on having used them in the past.
i do not like the fixed function thermostats because of lack of programmatic configuration and lack of ability to audit code. not bashing just stating my preference. i love customization to application
for context i just recently set up a dumb dc-dc converter with an independent hall effect current sensor on the input and output as well as input and output voltage monitoring to calculate real-time charge power and efficiency. it uses the microcontroller above and a tiny latching relay to control the remote on/off port of the dcdc converter. by writing the code my way i can ensure it functions in my preferred way
the two options for this situation that seem somewhat suitable in my view (which could be wrong) are cut PV input or communicate stop and start command over data bus.
it seems like you are familiar with arduino already so good luck!
curiouscarbon
Science Penguin
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- Jun 29, 2020
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by the way this exists
www.adafruit.com
it’s a 24usd microcontroller that has a built in CAN bus transceiver, which means it ought to be able to communicate with an AIO if programmed with some DIY code. it has usb-c to connect to computer if wanted.
there are members around the forum who are actively exploring these types of custom arduino type CAN bus communication translation, some reporting good results. for the most part, more complicated than just flipping a relay though.
adafruit has supplied me with good circuit boards and breakout boards in the past, and there are certainly other cheaper arduino style microcontroller with CAN bus from other sources
Adafruit Feather M4 CAN Express with ATSAME51
One of our favorite Feathers, the Feather M4 Express, gets a glow-up here with an upgrade to the SAME51 chipset which has built-in CAN bus support! Like its SAMD51 cousin, the ...
www.adafruit.com
it’s a 24usd microcontroller that has a built in CAN bus transceiver, which means it ought to be able to communicate with an AIO if programmed with some DIY code. it has usb-c to connect to computer if wanted.
there are members around the forum who are actively exploring these types of custom arduino type CAN bus communication translation, some reporting good results. for the most part, more complicated than just flipping a relay though.
adafruit has supplied me with good circuit boards and breakout boards in the past, and there are certainly other cheaper arduino style microcontroller with CAN bus from other sources
Stc-1000 is another one that is used for gazillion projects:
12V 24V 220V STC-1000 Digital Temperature Controller Sensor Thermostat | eBay
Find many great new & used options and get the best deals for 12V 24V 220V STC-1000 Digital Temperature Controller Sensor Thermostat at the best online prices at eBay! Free shipping for many products!
www.ebay.com
AIO is hybrid and has grid fallback. Grid would still charge the batteries. I suppose I could do two relays and use a standard thermostat.
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