charging battery
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highdesertranger
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have I done it? no.
very inefficient to many conversions. think about it you are taking 12v converting to 120v and then back to 12v. remember no conversion of energy is 100% efficient. you have loses at every conversion, the less conversions the better.
highdesertranger
very inefficient to many conversions. think about it you are taking 12v converting to 120v and then back to 12v. remember no conversion of energy is 100% efficient. you have loses at every conversion, the less conversions the better.
highdesertranger
bass_sears
Active member
More details? What are you trying to get done here?
If I had to guess I'd think you're hoping to just charge your "house" battery while driving without having to run heavier gauge cable from the engine compartment to your "house" battery. An understandable concern... for 25A @ 12v (300w) to your house battery you'd probably need to run 8awg wire from your start battery to your house battery... whereas 300w at AC 120v would be relatively tiny wiring. So if you're just going to do this while driving I'll disagree with the conventional wisdom and say you'll be fine, it's only 300w your alternator should be able to keep up with that and you've saved yourself a bunch of wiring through firewalls etc.
Now if this is ANYTHING related to what's going on when vehicle is NOT running you're in a whole different world, as already pointed out big inefficiencies going from 12v to 120v to 12v etc, better way is with proper large gauge wiring and dc to dc charging.
Keep in mind you need to look and see what your 120v battery charger wants to draw (don't overload the inverter, not always designed to work near capacity for long periods especially if they're cigarette lighter style and the cigarette plug is a horrible interface for higher amp draws), and keep in mind that it might take many hours of driving to charge your house battery if the draw (and therefore output) isn't very high wattage.
-- Bass
If I had to guess I'd think you're hoping to just charge your "house" battery while driving without having to run heavier gauge cable from the engine compartment to your "house" battery. An understandable concern... for 25A @ 12v (300w) to your house battery you'd probably need to run 8awg wire from your start battery to your house battery... whereas 300w at AC 120v would be relatively tiny wiring. So if you're just going to do this while driving I'll disagree with the conventional wisdom and say you'll be fine, it's only 300w your alternator should be able to keep up with that and you've saved yourself a bunch of wiring through firewalls etc.
Now if this is ANYTHING related to what's going on when vehicle is NOT running you're in a whole different world, as already pointed out big inefficiencies going from 12v to 120v to 12v etc, better way is with proper large gauge wiring and dc to dc charging.
Keep in mind you need to look and see what your 120v battery charger wants to draw (don't overload the inverter, not always designed to work near capacity for long periods especially if they're cigarette lighter style and the cigarette plug is a horrible interface for higher amp draws), and keep in mind that it might take many hours of driving to charge your house battery if the draw (and therefore output) isn't very high wattage.
-- Bass
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