Short_Shot
Solar Addict
- Joined
- Jul 13, 2021
- Messages
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Also OP explicitly stated he only wants to cover idle demand while towing, not necessarily charge batteries.
And your statement that 5% loss on 24v is "half the wattage loss" of 12v bothered me. It's not. 5% is 5%.
Let's assume 120w is available for easy math:
If you have 24v at 5 amps that's 120w. Losing 5% of 24v is 22.8 volts. 22.8v at 5a is 114w.
12v @ 10a is the same 120w. Losing 5% of 12v is 11.4 volts. 11.4v @ 10a is 114w.
So as you can see, 5% is 5%.
Though that's not at all how it works when a dc to dc charger is installed. What really happens is the current *increases* in that wire to still provide 120w of power to the device, and thus becomes 5.26a @ 22.8v and 10.52a @ 11.4v. This occurs because the charger is forcing the system to supply the 120 watts.
Or in the case of charging a battery @ 10a it's more like 136 watts, assuming 13.6 charge voltage.
And this doesnt even begin to touch the issues present with modern "smart" alternators which totally eliminate any possibility of charging through the trailer connector when they "intelligently" drop system voltage to save fuel.
And your statement that 5% loss on 24v is "half the wattage loss" of 12v bothered me. It's not. 5% is 5%.
Let's assume 120w is available for easy math:
If you have 24v at 5 amps that's 120w. Losing 5% of 24v is 22.8 volts. 22.8v at 5a is 114w.
12v @ 10a is the same 120w. Losing 5% of 12v is 11.4 volts. 11.4v @ 10a is 114w.
So as you can see, 5% is 5%.
Though that's not at all how it works when a dc to dc charger is installed. What really happens is the current *increases* in that wire to still provide 120w of power to the device, and thus becomes 5.26a @ 22.8v and 10.52a @ 11.4v. This occurs because the charger is forcing the system to supply the 120 watts.
Or in the case of charging a battery @ 10a it's more like 136 watts, assuming 13.6 charge voltage.
And this doesnt even begin to touch the issues present with modern "smart" alternators which totally eliminate any possibility of charging through the trailer connector when they "intelligently" drop system voltage to save fuel.
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