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Topic: Monitoring multiple 12v batteries? (Read 303 times) previous topic - next topic

MrBodger

I have been trawling some some threads, mostly fairly old and have not found
a complete solution to me needs.

Looking at using an arduino to monitor a bank of 12v batteries, these will vary
between 4Ah and 100Ah in capacity. Approx 6 or 8 batteries currently.

Each battery is charged from the same solar cells but independant from each
other. So if power is drawn from one battery it will not affect the others.

Ideally i would like to monitor the level from 12 feet away and keep an eye
on each battery to ensure the voltage does not drop below the level
where it affects the cells ability to recharge.

This varies as some cells have different chemistries.

Anyone know of any working and completed projects? 

Thanks.


CrossRoads

Resistor divider to drop each voltage down to 5V max, then a part like DG406 to mux the signals for analogRead() by an Uno.
https://www.digikey.com/product-detail/en/intersil/DG406DJZ/DG406DJZ-ND/821393
Or use a Mega with up to 16 analog inputs.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

MrBodger

Any advantage or disadvantages to either option?

I have several UNO's and just bought a MEGA 2560 with a ramps shield
so i can test with either.

Although the standard voltage will be 12.8 i presume i need to be careful
because on a day full sun the solar panel maybe putting out 20v (not tested)

Thanks for the quick reply.


CrossRoads

Mega costs more.
Since you are wiring up resistors anyway, one more chip is not painful.

Plan so that voltages Never exceed 5V, readings will just return 1023 if it does and tell you nothing.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Batman_429

You can use a 0-20VDC input board with ADC. You can build it by yourself using Amplifiers or if you are looking for a board which already has you can look into 8 channel 0-20VDC ADC boards. This solution has 16bit ADC resolution and its max input voltage is 20V so it will be able to monitor the voltage even in very sunny days.
this one has I2C communication so you can connect it with any Arduino board and read your batteries.

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