So i'm planning on doing some solar, and i'm just figuring everything out right now.My thought is that i'd like to have a 12v system being fed off 48v batteries, but the problem is finding a single buck converter that'll do 1000 watts at 12v.So i was wondering if there would be any problem with feeding a 12v battery bank with say, three golf cart buck converters that can do up to 360 watts each.I'm no electrician, but from what i've read having multiple buck converters wired to the same output can cause one of them to try and take all the load and overheat?Google's not being much help here, could use some input on my output.
>>2871048https://www.aliexpress.com/item/32305833052.html here's one for about $100, might find it cheaper if you look around. Why do you need a 12V battery bank AND a big 1000W converter?
>>2871048it's a bad idea. the outputs of each converter won't be exactly the same due to manufacturing tolerances. furthermore, the control loops that set the output voltage are not designed for master/slave operation and so they will be fighting with each other. the highest output voltage converter will back feed current into the lower voltage converters and potentially blow them up.when this happens, the most common failure mode for buck converters is for the switch to fail short circuit which means your 12V output then becomes 48V. this will very quickly blow up the other buck converters as well as any downstream circuitry that is probably not rated to 48V input voltage. if you're really unlucky the 48V battery will dump tens or hundreds of amps into the circuit, causing a fire and/or a battery explosion.
>>2871058I'd be using a large 48v system to charge a smaller 12v system.The 12v system would have an output of up to 1500w, so i'd like to be able to charge it at least around 1000w.>>2871068Good to know, thanks.
>>2871092>The 12v system would have an output of up to 1500wYeah but why? What 12V devices do you have that need 1500W at 12V?In the current economics of solar systems, assuming you are /diy/ing, it's far cheaper to just get a bigger inverter, bigger battery, more solar panels, and run everything off AC, than to fiddle with 12V variants of consumers to save 5% on conversion efficiency.
>>2871099Not a single device, but a single circuit.It'll be a portable power station, which can be used to feed 120 to a shed or workshop.A bigger inverter, bigger battery and more panels is in fact cheaper. Beyond a certain wattage.That's why there's a 48v system to feed the 12v in the first place.
>>2871048You can find plenty of oversized buck converters at Digikey. There's even a bunch that are meant to be jointly controlled in N+1 or 2N+1 configurations for redundancy.In any case, the voltage drop with 12V is HUGE and will nuke your efficiency unless you're using solid bars of conductors not wires. For anything over 6 feet power delivery you're better off using a transformer to go to 240v/120v and then down convert at the consumer.
>>2871324Also quick follow up, 1000w at 12V is 83A lol
>>2871250You could probably use all-in-one solar inverters to charge the battery from 120V AC wherever you have AC wiring, in terms of convenience I'd probably go with that, and in fact have gone with that. Though they probably only offer 30-40A charging currents.
>>2871250If you are trying to power one device that needs x watts with multiple paralleled sources that individually provide less than x watts but more than that when combined, you WILL have a bad time. Just split the circuits and run three wires. Or upsize your power supply. A power supply is a black box and without knowing its internals, you cannot just include it in a hodge podge high-capacity power supply design using just duct tape and bobby pins.
>>2871417I mean, upsize your power supply. If you don't need the combined power, then make separate circuits. It's a lot easier to manage over current situations separately than burning down three power supplies because your load was pulling more from one then the two others had to compensate when the first died.
>>2871048>48v batteriesJust buy a 48v inverter and be done with it.
