Battery draw question when cart is "Off"

[jondrew]

Newbie to the forum, so be patient if this should be in the FAQ (I did not see it)

I just bought a 2006 Precedent "PQ". Seemed in decent shape, has what appears to be relatively new Trojan Batteries (A5) stamped on the terminals which I believe are Jan 2015. The cart runs pretty good as far as I can tell. Still digging up documentation.

I wanted to hook up a 12 power converter to run new LED lights and some other accessories and was fishing around for a place to put the box. I took a good look in the battery compartment and saw what appeared to be a wasps nest underneath the heat sink of what I assumed is the speed controller. I took a bunch of pictures of all the wires for reference and then removed the batteries and cables. Those suckers are heavy. The "wasp nest" turned out to look more like a chunk of rotted wood that was jammed between the heat sink and the floor of the battery compartment. I removed as much as I could, and then cleaned up all the nasty looking areas with CRC battery terminal cleaner spray (comes out yellow, turns red if it reacts with battery acid). I vacuumed and rinsed the compartment out and put everything back together.

I made sure I put the batteries back in thier original sports (not that it should make any difference) and started hooking the cables back up. First I hooked all the jumper cables up, then the positive. I took a volt meter and checked the voltage between the positive post of the first battery and the negative post of the still unconnected battery and found it to be 51V. Then, with everything off and the tow/run switch in the tow position, I quickly touched the remaining ground wire to the battery terminal. I was a bit surprised to see a spark since everything is supposedly off. I swiped it again and got the same little spark. The un I connected the terminal, put the cover and seat back on and went for a ride. Everything seemed normal. Cart still goes about 23 MPH according to my GPS.

So the big question is, what is drawing power that caused that spark? Is something going on that will eventually draw my batteries down? These things don't really have a disconnect switch.

Comments, suggestions, references would be appreciated.

[dannyre]

Could be something as simple as the 12v converter itself.

[mrgolf]

It should have a pre charge resistor on the large post of the solenoid. This keeps the capacitors in the speed controller charged. They discharged while the batteries were out.

[jondrew]

In other words normal behavior? Makes sense. Thanks.

Originally Posted by mrgolf

It should have a pre charge resistor on the large post of the solenoid. This keeps the capacitors in the speed controller charged. They discharged while the batteries were out.

[Volt_Ampere]

The spark is caps charging up. Normal behavior.