12V battery meter

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koos147
Posts: 10
Joined: Tue Mar 10, 2015 2:16 pm

12V battery meter

Post by koos147 » Wed Aug 12, 2015 6:33 pm

Good afternoon,

We have a location running on battery (currently 1x 100Ah will be 3x 100Ah)
i will have some devices running there (at least a wifi router and a raspberry)

now i am interested in the status of the battery. currently we just charge it when we think it is almost empty.
i want to know the status and send it to the raspberry.
i guess i need some arduino for this (like the nano with usb or the etherten with lan)

is there anyone who have experience with this?

i have limited knowledge of arduino etc.
all help is welcome

Mark

angusgr
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Joined: Tue Apr 09, 2013 11:19 pm
Location: Melbourne, Australia
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Re: 12V battery meter

Post by angusgr » Wed Aug 12, 2015 11:33 pm

Hi Mark,

You can read a 12V battery voltage with an analog pin on either a LeoStick (USB) or an EtherTen (Ethernet). However the analog pins on either board are limited to 5V, you need a voltage divider circuit to scale the voltage and bring the maximum down to 5V.

There are lots of guides online to wiring up a voltage divider. Here's one for example:
http://www.instructables.com/id/DIY-Amp ... e-Divider/


Angus

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