I've got a project to add Arduino Pro Mini to sailboat. Main purpose is to show information about battery/usage, voltage and current on a 16x2 LCD.
AND cut off the battery from all devices, if battery voltage is too low. Then bring it back after it.
Sailboat gets its power from small outboard engine to be used small times when leaving/arriving pier.
Solar panel charges the system as well as it can.
Load on the boat is about 5A max, and 1-3A average, depending on outside conditions.
All of this will be made on Eagle and ordered on a PCB, mainly for the learning and because its cool! This will be my first project on others than veroboard
----- Ideas so far -----
Voltage divider of 100k/47k is used to measure battery voltage.
Current is analog output from ACS712-05 from ebay. (more of this later)
Fet to control Load line? No relay to save battery current. And takes a lot of space on pcb
Arduino Pro mini with headers to custom pcb
----- Questions -----
Are the ideas ok?
Because im working on custom pcb, it could be okay to add the ACS712-05 chip itself to the same pcb. No need for external pcb.s
What fets to use? Im thinking about using one output with 10k resitor to n-channel logic level fet. Which is connected to P-channel fet, with 10k resistor to source. Would it work? What to consider when switching the load?
And YES i do want to control highside(positive wire from battery)
Images does not include the acs712 on board, but it would easily fit between load and ground.
Feel free to comment. Images are not finished product. Traces on the pcb are just for clarifying what im about to.
Attaching a schema and a board layout to tell more than thousand words.