batteries dying???

[ThreeCW]

Originally Posted by OhDannyBoy

I bought a 300 dollar charger off amazon. its an 18 amp. i came outside this morning and it was still going. charge on cart was 38v when i took it off. it was 37v lastnight. should it have cut off or voltage been higher?

A new battery charger eh ... as Paul Harvey would say, "Now, The Rest of the Story". Here is a good one: https://www.youtube.com/watch?v=jQy3s4Pp4YA

Your batteries are not Trojans, but all lead acid batteries have a similar charge profile requirement (within a volt or two). A typical charge profile for 36 volt packs includes a bulk charge of about 44.5 volts and a finish charge of about 48.6 volts. I suggest your run another charge on your pack (even if they are fully charged) and check to see what voltage your charger is providing to your battery pack. See attached Trojan charging profile and voltages for more information.

What charger did you buy?

Trojan - Charging Voltage and Profile - Flooded.JPG

[OhDannyBoy]

JohnnieB, they are all sitting at 6.32 to 6.31. i could be mistaken on the charger still charging. the status light was green and measured at 38v plugged in. and also 38v unplugged. the charger was humming so i assumed it was "on". however, the fan was not spinning and after riding and charging it its red. checked water levels and they are good.

for more detail. it is stock motor with a refurbished 400 amp controller and 2g cables. i had a similar issue but much much much worse before replacing the f/r. i believed that issue was a bad connection. I thought maybe getting a hd solenoid would fix it. I did buy a cheapy. but i don't understand how it could be the same issue now when it runs fine for a while and then nothing.

i did want to double check though. with key off and out. should the reverse buzzer sound even though not able to run? there is a circuit from charge port still so i assume that's how power is getting to it.
Lastly, I have recently replaced the ITS sensor but I wonder if its possible i didn't install it right the nuts dont appear to do much to stabilize it.

[OhDannyBoy]

thinking about the ITS, I do still have the Molex connector on there. easy to fix. could this be the potential issue?

[JohnnieB]

Correct me if I am wrong. The cart runs normally for about 30 Minutes then quits. It doesn't progressively slow down, it just suddenly quits.

If it was slowing down progressively, it would likely be a charger or battery issues, but quitting suddenly points elsewhere.

A "refurbished 400A" controller waves a red flag. If it is the stock Curtis 1206 controller that has been modified to pass 400A instead of the normal 275A it was designed for, it might be going into thermal shutdown. Since it has taller than stock tires, the probability of a thermal shutdown increases drastically.

As ThreeCW suggested, try to run it again after giving it 10 minute or so to cool. If it runs normally again, replace the POS modified Curtis 1206 with an Alltrax sR48400 (or larger) controller.

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A cart wouldn't run normally, then quit with a poorly mounted ITS sensor.

The reverse beeper should should sound whenever the F/R is in R and no charger is connected.

[JohnnieB]

Originally Posted by OhDannyBoy

thinking about the ITS, I do still have the Molex connector on there. easy to fix. could this be the potential issue?

Yes, it is a potential issue. Doing away with the Molex connector will prevent future problems even if it isn't cause the current issue.

Same with the Reed switch in the charge receptacle. Bypass it if it hasn't already been bypassed.

[OhDannyBoy]

i have done that.

[OhDannyBoy]

im confused. are you saying the controller is shutting down or the motor is shutting down.

[JohnnieB]

Originally Posted by OhDannyBoy

im confused. are you saying the controller is shutting down or the motor is shutting down.

When a motor shuts down from overheating, they are burnt out and won't run again. If you are very lucky, a burnt out motor might be rewound, otherwise it is trash.

On the other hand, most controllers have heat sensors on the heatsink the MOSFETs are mounted on and if it gets too hot, the controller stops passing amps to the motor. When the heatsink temperature drops below the trip point, the controller will start working again.

[OhDannyBoy]

interesting. if that was happening would the controller be hot?

The first time this happened after installing the new f/r i was full speed and i just sort of felt it give out and we rolled to a stop. tried pushing the pedal down and the cart started its jerky lung routine. but then never worked again until the next day (didnt think to check for heat but had 38v.)

The second time was the next day and similar story except i was coming to a stop to turn into my driveway and and when i tried to go it did it. I sat there for a bit and then it worked and went about 200 yards no problem but did it again.

that's when i felt for heat and noticed solenoid and motor were hot but i could keep my fingers on it indefinitely so not too hot to touch just hotter than warm. controller did not appear to be warm at all. and I can hear a very high decibel sound that seems to be coming from the motor when i push the throttle but no movement.

If it was in thermal shutdown would it make this noise?

[JohnnieB]

The controller case may not be all that hot, the heatsink for the MOSFETs is one of the busbar type terminals (B-, M- or B+, not sure which) and has heavy cable attached to it, so it probably isn't very hot very far away from the MOSFETs.

High decibel or high Hertz (Frequency)? High decibel means loud. The output of that controller is chopped DC (PWM) and is chopped at 15kHz or so.