hantto
Member
I'm setting up an aditional battery in my car for all the misc systems that i have set up. I don't want to use the main battery, because then I would run the risc to deplete it and not be able to start my vechile again (as i like to listen to music while the engine is off among other things). I have inserted a relay between the batteries in order to keep them from equalizing their charge level when the engine is off. The relay will be closed when the engine is running and open when the engine is off. Now when you have the basic idea of my setup (se picture), let's look at my questions.
To keep the main battery from draining to the accessory battery when the relay is closed (engine on) I tought that it might be a good idea to put a current limiter between the batteries so that the accessory battery wouldn't steal all the charge current available. Is this nessesary? or is the alternor capable of charging both batteries, even if their voltage levels are different? Is a limiter needed?
A charging current of about 10-20A to the accessory battery would be suitable (it's a 60AH battery) to charge the battery during driving. Is the charging current too high (in aspect to the battery's life length and alternor's poweroutput capabilites?)? With what current are the batteries in cars nominally charged?
And here comes another problem: HOW would I limit the current without loads of powerloss. I calculated about 50W of dissipation with a simple resistor current limiter. Is there any suitable circuits out there? recommend one?
All this to keep the main battery as charged as possible the whole time.
Thank you for your time.
To keep the main battery from draining to the accessory battery when the relay is closed (engine on) I tought that it might be a good idea to put a current limiter between the batteries so that the accessory battery wouldn't steal all the charge current available. Is this nessesary? or is the alternor capable of charging both batteries, even if their voltage levels are different? Is a limiter needed?
A charging current of about 10-20A to the accessory battery would be suitable (it's a 60AH battery) to charge the battery during driving. Is the charging current too high (in aspect to the battery's life length and alternor's poweroutput capabilites?)? With what current are the batteries in cars nominally charged?
And here comes another problem: HOW would I limit the current without loads of powerloss. I calculated about 50W of dissipation with a simple resistor current limiter. Is there any suitable circuits out there? recommend one?
All this to keep the main battery as charged as possible the whole time.
Thank you for your time.