[solved] Battery monitor

[PaddyB]

Hello everybody,

I want to monitor the battery voltage. Mainly the determined values are to be linked with actions. The design should be as simple as possible. 3 Batteries should be monitored.

I've googled something and found the following things. I hope you can help with something in the selection of the parts.

If it's just voltage then it's worth considering an ADS1115
https://www.ebay.co.uk/sch/i.html?_from=...5&_sacat=0

Extremely accurate 4 channel voltage sensor. You'll also need something to divide the voltage down to below 6v, maybe something like this or do it yourself with some resistors -
https://www.ebay.co.uk/sch/i.html?_from=...pell_check

Then openplotter makes it easy to set up - 
https://sailoog.gitbooks.io/openplotter-...tools.html
One tip, it's more accurate to connect the ground from the ads1115 direct to the battery neg, then you don't include any voltage drop along the negative cables in the measurements.


Measuring current as well is a bit harder as you will need to have something which can measure up to the large currents used by the engine starter motor. 

IMHO logging voltage across the actual battery terminals is one of the most useful set of data on any boat living on solar/wind power. 

Sun's out!