Voltage reducer – battery drain?

[cobolnofun]

So I just finished the winter project which included a voltage reducer, street legal light kit, and a usb port. I had to rewire the key switch to make the voltage reducer work… but everything works fine now. I have no power to anything unless the key is on. So key switch and signal wire are good and the voltage reducer is at least wired well enough to power everything.

However, last week I took it for a spin before reassembly. I noticed the voltage was lower than normal, but chalked it up to me playing with the lights. After the drive, I noticed the charger was taking longer than normal to finish. Around 6 hours vs 3 hours I normally get for my short drives. So I figured I will leave it alone for a few days and see what happens. After the charge I had 38.5ish (can’t remember exactly). A week later I have 37.4. Cart has had the key off, in neutral, and has not been touched.

So I should recharge this thing. I unplug and plug back in; charger gets going and I notice the positive battery is making a humming noise. I unplug the charger and put a wrench on the negative terminal of that batter to tighten it and sparks. So I unhook everything. Remove the positive to the voltage reducer and re hook everything up without sparks. Plug in the charger and silence. WTF!

Batteries are all full and less than a year old. Charger was working fine so I doubt that is the problem. I just rechecked the wiring of the voltage reducer and that looks fine (constant hot capped, electrical taped, and zip tied away from anything metal).

Does a voltage reducer with no load really drain the batteries? I mean I will see the drain in a few days without the voltage reducer but this does not seem right.

Anybody have any suggestions? I almost want to buy a battery switch and interrupt the positive to the voltage reducer since I don’t drive the cart enough to have it draining this quick while parked.

[Mooncarter]

Without knowing what type reducer you have and how you have it wired I don't think anybody can help with this.

Sounds like you have several issues.

[cobolnofun]

https://www.amazon.com/gp/product/B01HPM7Y4U/

Which as far as i can tell is a re-branded version of the madjax reducer.

As far as wiring:
Reducer Yellow - 10 gauge to the Positive side of the battery pack
Reducer Green - 18 gauge to the switched side on the key switch
Reducer Black - 10 gauge to the negative bus on the fuse panel (Blue Sea Systems 5025)
Reducer Red - 10 gauge to the positive bus on fuse panel
Reducer Blue - capped, taped, and tucked out of the way.
Negative on fuse block - 10 gauge to the negative side of the battery.


Light wiring harness goes to fuse block both +/-

Usb port goes to fuse block both +/-

The lights and usb do not work unless key is turned.

[Hunter450]

The blue tapped up wire has me concerned. A voltage reducer equipped with a trigger wire uses all 5 wires. The larger 10 ga wires (red & black) are probably on the 12 volt output side of the reducer that should be connected to your Blue Sea (+) & (-) buss bars. I don't think there is a need to run an additional ground wire from the fuse block buss back to a battery. The ground for the reducer system is made on the higher voltage input side. Did you get a wiring schematic with your reducer? Devil is in the details.

I went back and looked at the Amazon add and now I understand why the blue wire is tapped up. (Constant 12v for things like radio's with clocks and memory).

[Sergio]

The connections are correct based on the information found on the Amazon link provided.

The part I am confused is:

I unplug the charger and put a wrench on the negative terminal of that batter to tighten it and sparks

Was there a loose connection or exactly what sparked?

Make sure the main cable lug is in direct contact with the lead surface of the battery post and any other small gauge wires go on top of the main lug.

[Hunter450]

I still don't see a ground connection on the high voltage input side of the reducer? Is this an issue just providing a ground on the low voltage output side?

[Sergio]

That is fine, that reducer has a "common" negative.

Unless the reducer specifically mentions "isolated", running all negatives to a single buss bar or fuse block works well and only a single negative is needed to the converter.

[cobolnofun]

Originally Posted by Sergio

The connections are correct based on the information found on the Amazon link provided.

The part I am confused is:

Was there a loose connection or exactly what sparked?

Make sure the main cable lug is in direct contact with the lead surface of the battery post and any other small gauge wires go on top of the main lug.

I assume it was loose based on the spark. It sparked out between the cable lug and lead on the terminal. And i am talking 1/16th of a turn on the wrench.

It was one of those moments where i thought: this humming isn't right and sounds like it might be coming from the negative terminal, lets see if its tight. Then sparks. At that point i decided to unhook the pack before rechecking tightness across the board.

I have the main battery cables on the bottom touching the lead surface. The only questionable thing is the heat shrink on these cables is a little on the flat surface. Also i had some battery protector spray on there.

[Sergio]

Perhaps it was the heat-shrink, You better off cutting any heat-shrink that goes near that flat surface and could prevent the lug from making good contact with the lead surface.

[tellico416]

Cobolnofun- Thanks for the information about your install. Any improvements since your last post in finding out what was causing your unexpected battery drain and longer charge times?

I have purchased the exact same reducer to install on my 2014 precedent as well in order to "fix" the way the shop had wired my light kit using only two 2 8V batteries. The battery pack, like yours, is only 1 yr old and functioning very well....so don't want to do anything to cause a constant discharge load since I only use the lights infrequently at best. Why create a problem that may not have been an issue if I was only going to use them infrequently..right??

I was actually thinking of installing the reducer w/ fuse block (and moving the lights circuit to it) and then removing the main supply fuse in the yellow 10 gauge wire from the pack positive supply lead and only re-installing the fuse for the occasional use when we may take it out for an late evening cruise and need lights.

I think Sergio clarified in a previous post that all reducers with the desired switch wire only turn off the load side of the converter, not the converter itself when the key in the "off" position. That load while off is described as being only a few milliamps enough to keep the internal capacitors charged. Nobody advertises the watts used by the converter while the key is "on" and no 12V loads are in use. My reducer (same link as yours from amazon) came with no serial number or operating specs/information at all. Only a warning not to mount the device on plastic that the heat generated could harm. Its dark blue, bigger than the OEM version at 4X5X2", 30 amps (rms?) and lots of heat sink fins. I want to put it in the battery compartment behind the forward/reverse switch and mount it on a thin piece of metal to the plastic tub wall. Where did you end up mounting yours?