Trolling Motor Question

[wvbasser]

Can anyone please tell me whats the difference between 12,24,36 volt in trolling motors.

[deer0373]

12 volt-uses 1 battery-less thrust, doesn't last as long on a charge-cheapest
24 volt-uses 2 batteries-more thrust, lasts longer on a charge-more expensive
36 volt-uses 3 batteries-max thrust, much longer on a charge, most expensive

[SlamBait]

good info thanks

[TRCM]

You can also think of it this way when it comes to power & speed

12v = 90 hp
24v = 150 hp
36v = 225 hp


But, when it comes to which one last the longest on the SAME speed

36v = 90 hp
24v = 150 hp
12v = 225 hp

Due to the way current draw and batteries work, if they are all on the same speed, the 36v will last longer, cuz each battery sees only 1/3 of the draw that the 12v sees

[Skeet'r89]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TRCM &raquo;</TD></TR><TR><TD CLASS="quote">
But, when it comes to which one last the longest on the SAME speed

36v = 90 hp
24v = 150 hp
12v = 225 hp

Due to the way current draw and batteries work, if they are all on the same speed, the 36v will last longer, cuz each battery sees only 1/3 of the draw that the 12v sees</TD></TR></TABLE>

???????? Don't understand that

[TRCM]

OK...let's say the trolling motor draws 50 amp @ medium speed.

Let's also say a 12v battery can supply a 50 amp draw for 6 hrs before it dies.

Now, a 12v trolling motor will only last 6 hrs (50 amps /hr for the 6 hrs the battery can supply)

Now, a 24v trolling motor will draw 50 amps, but since only 25 amps comes from each battery, each battery will last 12 hrs instead of 6 since only 1/2 as much is being drawn off.

Likewise, the 36v trolling motor also draws 50 amps, but since each of the 3 batteries only sees 1/3 the draw (or ~ 16 amps), they will last ~ 19 hrs each.


This is a generalization to make the example easy to explain. No, the difference in how long they will last is not quite so drastic, but it isn't all that far off either.

No matter how you look at it, as long as the current draw is the same, 2 12v batteries in parallel (24v setup) will last slightly longer than 2 12 v batteries used one at a time.

A 24v setup will have the capacity (long term, not short term) roughly 2.2x that of a 12v. A 36v setup will be roughly 3.4x the 12v set up.The reason is each battery sees 1/2 or 1/3 the draw, but due to the nature of electricity and batteries, as the draw is lower, the length of time it can sustain the draw goes up, and it is not a linear change. The draw rate is the inverse of the lenght fo time it can sustain it.

So, the less you pull out of the batteries, the longer they will last. If you use a trolling battery as a startign battery, you will kill it quickly since the battery is not built to withstand the large and sudden current draw. it is instead built to handle a small steady current draw.

[Skeet'r89]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TRCM &raquo;</TD></TR><TR><TD CLASS="quote">But, when it comes to which one last the longest on the SAME speed

36v = 90 hp
24v = 150 hp
12v = 225 hp

</TD></TR></TABLE>
This is the part I don't understand, I see no relation to the situation.

[TRCM]

Wow...well, a 90 hp will go farther on 10 gals of gas then a 150, which will go farther than a 225.

hence, the charge on batteries last longer in a 36v system than a 24v will, and 24v last longer than a 12v will at the same speed.

can't make it any simpler

[Skeet'r89]

[FFMedic]

very good explanation. thanks for the time u took to post it all! i get it but had to reread it...it's early yet!
D.