Lifted Ezgo with 400 Alltrax DCX

[JohnnieB]

Originally Posted by jchcart

Changed it to progressive, felt crappy, changed back to linear, the lowest it got going around the block flooring it and letting off and flooring it again was roughly 31.9 - 32 but that was just very briefly as well, seemed like it would stay right about 34.8 and creep back up to around 37

1. Measure between the controller's B- and B+ terminals and do the same trip around the block.

2. Measure between the controller's M- and B+ terminals and do the same trip around the block.


3. Measure between the controller's F1 and F2 terminals and do the same trip around the block.

That will tel us if the pack voltage is getting to the controller and if it is passing through the controller. (Voltage applied is same as voltage out at 100& throttle)

The Voltage to the field windings probably should be 20V or above when accelerating from a standstill (Low RPM and high armature amps) and decrease to 5V or so when at top speed. (High RPM and low armature amps)

[jchcart]

Hey guys,
Sorry I’ve been away my grandfather passed very unexpectedly and I have been really tied up with everything. I did find a battery cable that was a little corroded and it and another one had really long cables, so I shortened them down and cleaned all the corrosion I could off of them. I am wondering how much of a difference would it make to go from the 4 gauge wires I’m running to 2 gauge? the battery pack is about 7 months old, not sure if it’s normal but I haven’t had to add any water at all to any of them yet. I would hope they are all still good being that new but I know they can go bad at anytime. JohnnieB on the requested tests above, I need to hook my volt meter to those terminals and then give you the readings while I’m driving it around the block?

Yes the solenoid is an upgraded one that came with the 400 alltrax controller when I got it. It seems to get hotter than what I think it should when in use and has since I installed it. It is a 4 terminal 800 peak 200amp continuous

[JohnnieB]

Our condolences to you and yours for your loss.

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Cables:

The power loss for 17' of 4Ga copper passing 400A is about 675W and about 425W for 2GA, so there is about 40% less power loss with 2Ga cables IF the 4Ga cable are in perfect health, which they aren't.

All cables have power losses and it is in the form of heat, so they warm up during operation. In general terms, they shouldn't get warmer than about 10°F above the air temperature. If any of the 10 high amp cables feel hot, they are either bad or undersized.

A 400A controller is at the tipping point between 4Ga and 2Ga and going to 2Ga for 400A and smaller controller doesn't hurt. (Actually, the improvements in performance are less when using the lower amp controllers, so the law of diminishing returns on the higher cost applies.)

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Batteries:

The batteries are less than a year old and if they have been kept charged, they ought to be in decent health.

They only dropped to about 31V under load, so they appear to be healthy, but will drop further going up that hill with 4 people onboard.

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Voltage readings:

The three I asked for are taken while cart is moving, so for safety reasons someone other than the driver ought to be reading the handheld DVM. Or if you have a DVM with a Hi/Lo function, the meter can be read after the cart stops.

Voltage #1. Looking for the minimum voltage applied to the controller when under load. Should be the same as the battery pack voltage as measured at the charge port.

Voltage #2. Looking for the maximum voltage applied to the motor's armature with pedal on floor traveling on the same stretch of road where Voltage #1 reading was taken. Voltages 1 & 2 should be equal when controller is wide open.

Voltage #3. Looking for both minimum and maximum voltages while cart is moving, so Hi/lo function must be set while cart is moving and the readings taken before cart stops. Going slow and pulling hard will have a higher voltage and traveling at top speed will have a lower voltage.

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Solenoid:

The heat is most likely from the coil, it has about an amp flowing through it all the time it is energized.

Check to make sure it's not staying energized when it shouldn't be.

Of carouse the contacts may be dirty or burnt, so connect a DVM between the 2 large terminals and measure the voltage.

Should be about 5V when de-energized and about 0.0V when energized.