Step up voltage rather than step down?

[Skrilex]

So, if I swap to a non mil motor for Power, my preference would be to keep it 12v. Seems easier and cheaper. Then, if I need 24v for the chassis to operate, why wouldn’t we instead of stepping down, step the 12v up to 24v to run the wipers blowers and ligts? That way we would know the load and it wouldn’t change, at least in my application, and we could have a single battery system. Seems a little easier to wrap my head around. Am I missing something?

 

[ken]

Why not just use civi H1 lights, wiper motor, and heater blower motor? Then just replace the bulbs with 12V. Easy peasey

 

[riderdan]

You can do a step up transformer, but you have to account for the fact that the primary input voltage times current is equal to the secondary output voltage times current. (Vp x Ip = Vs x Is). So if you're pushing 12v at 60 amps into the step-up, you'll get 24v but only 30 amps out. So you'd need to be sure to put an alternator that can handle whatever your 24v draw is into it.

 

[Skrilex]

I haven’t priced that out but I’d guess it’s into the 4th digit to do that.

 

[Skrilex]

https://www.amazon.com/dp/B01M0IEYZ...etailBullets_secondary_view_div_1516661532849

so is the 30a on this one related to the input or output? Would seem to be output by the way they describe it.

 

[papakb]

There is no such thing as a DC transformer. When upconverting DC you use a voltage doubler or converter but the current determining factor is POWER as riderdan pointed out. Power is similar in both DC and AC circuits when you use a voltage converter only there is a small amount of power needed by the converter to operate so it isn't a perfect 2 to 1 ratio. Most good voltage converters will have an efficiency (or conversion) rating so feeding 12v at 10 amps (120 watts) into a 95% rated converter your going to get about 114 watts out which equates to 4.75 amps at 24 volts.

The thing you need to be careful of is to make sure the converter you install is large enough to handle the maximum current load you expect to see on it and to use large enough guage wire. If you search American wire guage you find charts that give you that information.

INVERTERS are used when changing DC to AC.