Charging and Monitoring a Lead Acid Battery Using PIC

The time of building your own project is over,it is time and money consuming.

Buy volt/amp panel meter, it worth only less than $20 in the market.

For this application

For voltage measure directly, or if your PIC cannot handle an analog input of at least 28V then use a two resistor voltage divider network.

http://en.wikipedia.org/wiki/Voltage_divider

For current you can use a series shunt and directly measure and scale the voltage within the PIC microcontroller to get your battery charge current.

http://en.wikipedia.org/wiki/Shunt_(electrical)

Both solutions are simple, inexpensive and fairly accurate. I am assuming you know that the lead acid battery charger will still feed a small amount of current into the battery even when it is fully charged (and as such your "battery charged" indication needs to be set at some current value above 0A), and that the battery charging rate and current follow a non-linear curve.

Have fun with your project.

Previous questions about same sort of problem

http://cr4.globalspec.com/thread/60596

Battery monitoring software

http://www.google.co.uk/search?q=lead+acid+battery+monitoring+software&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=fBKlTJ2AEcSb4AaoheHSDQ

Take a look to these BMS (Battery Monitoring System) manuals:

http://www.ablerex.com.sg/downloads/products/Enerbatt3G_UM.pdf

http://www.btechinc.com/docs/S5/PIT-12%20-%20User%27s%20Manual.pdf

- MS

Please take a look at a gizmo called the "BatteryMinder" and avoid at the need and extra fuss of monitoring the status of the battery charge because it'll charge the battery automatically in several modes. Also, it conducts de-sulphuring of the battery.

I recently bought one for $99.99 @ Northern Tools and it has worked beyond all of my expectations!

www.northerntools.com/

Good luck!

GA for that one

This seems to be very good product. I asked question to them whether this product could be used at 110V 50Hz instead of 120V 60Hz.(As quite many chargers of other use, like for electric shaver etc. are suitable for 50Hz as well as 60Hz). Their reply is that it is suitable for 60Hz only. Could any one suggest similar product which could be used at 110V, 50Hz?

Thanks for the vote of confidence Peter!

I failed to mention that there are several other brands of similar charging/monitoring devices out on the market, but the BatteryMinder is the latest and greatest in cutting-edge technology.

Be forewarned that they are in such high demand that the factory can't keep pace with orders! My order was backlogged for nearly 2 months! YIKES!!!! Glad I finally received it because it has restored a cranky lead-acid battery in my Dodge Avenger that was constantly dying from improper charging techniques caused by my "ancient" battery charger!