I saw a video on Youtube where the guy has a 12v to 24v convertor because he didn't have room for a second battery. He was using a Lithium 100Ah battery.  Anyone here try this with any success with a lead  acid or gel cell battery.  An interesting solution to upgrading to a 24volt trolling motor with out having to buy to batteries 12 v to 24 volt converter. https://www.facebook.com/100009055845283/videos/2446614952317009

You can't easily convert 12VDC to 24VDC.  You're going to have to convert it from a DC source, into an AC source, and then back into a DC source in order to raise the voltage.  All of those conversions are going to eat up a lot of power.  That's going to effectively change your 100Ah battery into something more like a 30-40 Ah battery.  Beyond that, you're going to have a lot of trouble getting much current draw out of a setup like that.  So more than likely, your trolling motor will never really hit top speed, especially if it's a larger trolling motor.  The maximum current of a normal battery is limited by the load applied to it and the batteries internal resistance.  With this voltage doubler added, that becomes the limiting factor on your max current draw.  Beyond all of those issues, you're going to have reliability issues trying to keep all of this added circuitry going in a wet environment without overheating.

 

This is why everyone who's smart just uses two batteries.  It's safer and more effective.  If you want to save room, then just buy two smaller batteries.  Two 30 Ah batteries would work just as well as what he has set up, and since you have two of them now, it would be really easy to find a place to store them.  

If if was a good idea more people would do it.

I don't see any benefit to doing this.

For starters  you would lose power in the conversion.

Extra thrust would be the only possible benefit, but it would not last long.

If you figure an average 70lb motor, at 24 volts draws a little over 40 amps

To get that 40 amps at 24 volts, the12 volt battery would have to put out over 80 amps. 

Volts X amps = watts (power)

24 X 40 = 960 watts      960 ÷ 12 = 80 amps

 

Even at slow speeds the 24 volt motor would take more power, because of what is lost in the conversion.

Bad idea.  Too many YouTube heroes out there.

 

 

 

1 hour ago, kjfishman said:

I saw a video on Youtube where the guy has a 12v to 24v convertor because he didn't have room for a second battery. He was using a Lithium 100Ah battery.  Anyone here try this with any success with a lead  acid or gel cell battery.  An interesting solution to upgrading to a 24volt trolling motor with out having to buy to batteries 12 v to 24 volt converter. https://www.facebook.com/100009055845283/videos/2446614952317009

I would listen to the above advice. It's spot on