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Old 04-26-2015, 05:40 PM   #1
fishsticker
Gone Wild
 
Join Date: May 2010
Location: FS LOUISIANA
Posts: 158
Default What kills controllers?

The rest of the story………………..I am fairly mechanically inclined, a professional Civil engineer and carry a second degree in Mechanical engineering. I am by no means an electrical engineer or proficient in anything electrical. About all I remember from my EE classes is V=IR…….Well I remember a little more but not a whole bunch.

After much deliberation I am now the owner of a bad boy buggy
Now I have heard about all the complaints and bad reviews but have always wanted a 4WD electric cart to hunt off of. Recently my son and I have gotten into the night hunting game and of course need one more than ever now!

So I made a deal with the previous owner of a non-running Bad Boy Buggy. I fix it and deduct all parts from the sale price of $4500. The cart looks to be in great shape fairly well cared for and garage kept. He said it does not get used 5 times a year and it’s a 2010 XT. Only thing that looks bad on the cart is the battery trays and steel structure in that area. Fair amount of rust from battery acid corrosion.

I get the cart home and start working on neutralizing all the acid in the battery compartment and generally cleaning in there, checking wiring and connections…..all the stuff you would do to a cart you just brought home. I used a gentle spray from a garden hose after spraying down everything with a bottle of baking soda and water. After cleaning it up I turn the key on again and place in forward. It moves! I let it dry and pull it into the shop and put it on the charge……….and the 8 6volt batteries took about 4 gallons to fill to the proper level……..

The next day I get in the cart to go take a spin and nothing. You can hear both contactors energize when you turn the key on and then one or both drop out. This cart has the two blue SEVCON controllers. Front motor controller is flashing 4 blinks and the rear is flashing 5 blinks…..back to that later. After looking on this site I learn how to properly bench test both contactors and what do you know... the one for the front controller is bad and the one for the rear motor controller is good…..interesting. I go buy two new contactors and install.

With both new contactors installed I turn the key on and hear both energize and then one drops out. I also notice that the front motor controller’s green light is lit solid and the rear motor controller is still flashing 5 blinks….. Press pedal and its alive!! Well half alive. Front motor pulls good and rear motor has no juice.

Again after wading thru the wealth of knowledge here I find a good procedure to test the rear motor for ground and do a run test. I disconnect all leads to the rear motor stick her on the lift and the motor test fine and runs forward and reverse……..

I double check the new contactor for the rear motor and decide it must be the controller. I make a trip to a local bad boy buggy dealer and luck up and find a helpful, knowledgeable tech. He says that yep….the five blink is indeed the death blink for the controller. They sell me a new controller and offer to program it for free after I install it…..good thing because I am not a SEVCON controller programmer…….

Get it installed and get it programmed and all is well…..both front and rear motors pull great. Even with the poorly maintained 4 year old batteries we get about 5 miles of travel our first night out with some juice to spare.
So now I am liking the cart I don’t think I have made too bad of a deal….$4500and that includes the parts cost of both new contactors and a new controller. Besides a poorly maintained battery pack with a fair amount of corrosion in the compartment the cart looks like new.

So we make a few hunts off the cart and love it. Today I decide to clean her up real nice. Very careful about cleaning the battery compartment…..only use a light spray from the garden hose and no direct spray on the contactors or controllers…..I even hand washed the rest of the cart and put ARMORALL on the tires!

I make one trip down the driveway to the mail box and back and park it. An hour later I hop in the cart and hear the dreaded click of a contactor dropping out. I pull the seat and see 5 blinks coming from the front controller! Unbelievable!
What the hell would make the front motor controller go out within 20 miles of replacing the other one? Are these things allergic to water vapor?

So………….what kills controllers? This cart can’t have many hours on it so it is not like these controllers have thousands of hours on them. From what I have read a short in a motor can kill a controller and obviously they will just fail over time from use but I can’t believe a low hour cart like this would have both controllers dead within 20 miles of each other. I have heard of SEVCON controllers. I have seen their name around and have even specified equipment packages with their controllers. I thought they were a high end manufacture.

For those that don’t know how this cart is set up here is my simplified explanation.

1 48 volt battery pack.
2 motors 1 front and 1 rear.
2 contactors
2 separate controllers

Each motor is controlled by its own controller which gets its juice from the battery pack via its own contactor. It appears to me that when the key is turned on the controller energizes its respective contactor and if all is well stays ready to send power to the motor. Currently, the controller for the rear motor that is blinking 5 is dropping the current to its contactor after about 1.5 seconds.

I guess I’ll go pick up another controller tomorrow.

So.......... what kills controllers?
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