Computer Monitoring of 12V Battery

Yes a voltage divider is the common way to go but if you have to "guess" about that there I'm not sure how you are going to solve all of the other design issues

dan

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Dan Hollands

Well put!

yes, Brian, a voltage divider is the right way to do it. There are other ways, but they are cumbersome. There are microcontrollers with built-in A/D converters.

Prediction of remaining useful battery charge would be specific to battery type, battery age, and ambient temperature changes, but you could make one that 'learns' , sort of.

I suspect that your solution lies in one or two simple comparator type circuits that let you know when thresholds are crossed. Keep in mind that a rechargeable battery in active service in, say, June, has a different capacity two year later, probably.

good luck, Geoff

Geoff,

Thanks for confirming my rusty memory. I was thinking of using a PIC to do the monitoring. Thanks for the help,

Brian

Your life might be greatly simplified by the purchase of a charge controller IC for the specific kind of battery you want to monitor.

Battery monitoring is mostly futzy guessing based on many parameters - since you like PIC's the Microchip PS200 may be your friend:

Because the parameters can be futzed with. Maybe you can even buy the development board. Thats what I always do for a 1-3 off.

Maxim got similar things.