wiring batteries

[soonerfisher]

I have 3 batteries wired in series for my 36v trolling motor. Can I wire these same 3 batteries in parallel, or make a wiring harness or something so that I can get 12v with equal draw from each battery, to run my bait tank pump?

[snapperd1]

Soonerfish,

Take a minute and draw yourself a picture. If you do what you are suggesting you will short out your batteries. I had to draw a picture for myself, but I think if you take the time to draw it out you will see the problem right away.

Good Luck

TD

[snapperd1]

Thinking more about it you could do what you want but you would have to have three sets of power leads coming from your pump. You could connect one set of leads to each of the batteries. But like I said above you don't want to run the same set of batteries in parrell and series.

Good Luck
TD

[r1dermon]

it would work fine. and your pump would last 3 times as long. lol. as long as you know how to wire them in parallell. i do it all the time in my RC boat, i have the equivalent of 43.2v on my r/c boat, with that running in series my motors would spin 60,000rpms for about a nano second, then my speed control would melt right out of the box and through the hull, sinking my boat. lol. but since they are wired in paralell the motors(built for 14.4) run half speed, enough to plane out, and my setup will last almost an hour at full throttle, vs. 8 minutes on 14.4v.

[itwonder]

You need a DC-DC converter, along the lines of Digikey PN 102-1262-ND, assuming 6.25 amps is enough to run your pump with reserve. This particular one is a basic electronic module without packaging; some other vendor may offer something more tuned to marine use and ready to install. You want one that handles 36 V input, provides 12 or 13.5 V output, and has an amperage rating to match the current draw of your pump plus a reserve of around 50%.