T2 controller Issues

So I know it’s gonna sound crazy but is it possable that something could have broken in my controller to cause Excess Power draw???

Here is what’s going down. My car has worked fine for months. A few months back my car seemd to be not going as far. I thought my batterys (DEKA Gells) were just getting old and soft. So I bought a brand new set of batterys and installed them. Well the new batterys offer no more or better range and or performance. And that Leeds me to think something in the controler is dumping voltage/current and my car is lacking range. My controller is a re built controller from Flight Systems. I have made No program setting changes since I installed the controller. I used to work with Marlon and he would help me trouble shoot things like this but Marlon has gone MIA and after repeated calls, messages and texts I have had no contact with him leaving me to ask the question her. Does anyone have any Ideas. My only thought is to switch out my controler with another T-2 and see if that helps? I don’t happen to have a T-2 laying around right now to test, anyone have any ideas??

The controller would tell you anything unusual.

Only sure way might be a swap!

Is it working harder? Brakes bearings speed?

Generally something gets hot if power is wasted.

Rodney monitors his power draw and could help you compare.
You can monitor with Sentry sw or with a meter.

Have you changed out tires. I swaped out my OE tires to a set of turf tires on wide rims and lost 6 miles of range. My amps went up and I’m trying to sort it out right now.

Tire pressure has a big effect going from 24 to 40 pounds has a big effect on range.

I just got a new ammeter that i’m going to install when it gets warmer. I will be able to give more accurate information then.

Front end alignment also affects amp draw as well as handling. If your wheels are in or out at the bottom you need to check the toe. To much either way can make the cart squirrely as well as being a power robber.

I have 2 gems. Both have the same size wheels. And tire pressure. My Blue car (the one in question) gets 1/2 the milage the the other. If it was the tires causing lack of range then both cars would have similar range.

Like I said the car Used to do just fine and all of a sudden the range is not what it used to be

Could be wrong, but to answer your question: I don’t believe there is anything in controller that could sink that much power without overheating.

That is not to say the controller isn’t sending power out in an inefficient way.
But then motor would overheat.

How about accessories? Anything else using power?

You need an ammeter to compare the two cars. As always, suspect batteries. In fact, they might be easier to swap than controller.

Do you know someone who could test battery capacity?
If not, do you have a load, lights etc., that you could leave connected while timing discharge?

New ver. MM speed fix went out today.

The first thing I did was test all the batterys. I wrote down all the cold cranking numbers of each battery as it was tested and they all tested great up over 600+ cold cranking amps

Long shot BUT: Take your motor apart and clean it. If there is a black powdery substance between the stator and rotor it can cause a bit of a drag. While you have it apart clean and free up brushes.

Note for anybody reading this. If you have a ventilated motor you need to free up and clean brushes every 3 years, Dirt and debris entering thru the vent holes causes brushes to hang up and the end result is motor failure.

Cleaning the brushes? It’s worth a Try? I highly doubt it but it can’t hurt. It would be nice to make a “how to video” of brush cleaning and just a general maintaince video.

Cleaning the accumulation of black dust etc from the stator housing helps.

2 things I have overlooked 1 is tire pressure. Doing some "Armchair Engineering " my loss of range has NOT come all of a sudden but slowly over time, kind of like a slow leak in a tire? Wouldn’t it be funny when I go back to check things out that I have Low tire pressure. It’s never that easy but sometimes it just is. #2 is front wheel “Tow” this is the angle of the front wheels to much to could cause drag and loss of range. 2 small things that could add up to create the issue. I’m excited to do some investigation. Right off the bat I bet my tires are at 30 psi. So the first thing I’m gonna do is put them at the Max Tire pressure. :slight_smile: #2 I’m gonna make a wooden Jig that will attach to my wheels that will allow me to accurately measure my Tow in adjustment.

To adjust tow you need a flat drive way, a magic marker, a square, and a tape measure.

Take your square and put it against the fattest part of the front of the tire and put a mark on the pavement. Do the same on the rear part of the tire. do the same on the other side. Back the cart out of the way and measure the distance between the marks.

Assume you will get an addition 1/8 inch of toe in when under power because the wheels are pulling foreward.

!/4 turn on each tie rod will move the toe about 1/8 inch+/-.

I try for straight ahead to 1/8 toe in as measured.

Here is my tire pressures

RR- 19

Pretty low. I pumped them all up to 40psi and It did seem to make a slight difference. I was looking for a much higher jump in Range and performance. At 66% the car seems VERY sluggish. I don’t go to 50% or lower but the lower % range of battery life is just not good when it comes to climbing hills. On the flats it’s fine spins up to 40 Mph no problem

I’m gonna go attack the tow and see where the car is set at thanks for the info

Grant send me a print out of your controller program


Try swapping out chargers. Is charger on the right setting?

Here is a way to compare battery capacity using local materials and a volt meter.
Start test fully charged.
Compare voltage after say 5 hours.

Be careful-72volt.
Connect with switch off.

Dumb question. Are you checking range after an overnight charge or after the BDI says 100%

Power meters that read AH direct are available on Ebay for <$10.

Unfortunately limited to 60 volts.

Here is a voltage divider circuit to use on Gem car.

Or you could test battery in 2 banks of 36v each which might help equalize them.

As shown it only dumps about 3 amps. May take 24hrs to test.
Double meter reading as only 1/2 power is measured.
Probably would not need water cooling.

Add more load for faster discharge.
If someone wants to make a more permanent test jig. I have access to load resistors.
Last pic is for discharge testing 12-24 volt batteries.

Could do a Gem if you have a week.

What setting on the controller would cut back or adjust down the power draw? Would field current do it. Example is there a adjustment that would cut back the power to the motor potentially decreasing performance that could help me save some power.

When I first installed the motor and Controller Marlon helped me program the controller. I think the settings he gave me were designed for performance NOT efficiency. Example my car has a pretty aggressive take off. If you smash the gas it will spin the wheels. You have to be very light on the gas and I’m sure just adjusting this setting down could help save some power.

Let me know what settings I could use to save some power.

Rodney to answer your question range is checked after a night of charging Both my charger and BDI and Batt Six display all say 100%.

After my battery’s are fully charged the charger go’s into a float stage. I checked voltage at each battery while charger in in float stage and all the batterys we with in range and in good status