EZ-GO TXT - Voltage Drop after 20 min driving

[steven2020]

Sorry for just getting back to this thread now. I’ve been out of the loop in most things lately. The new HD solenoid fixed my bottle neck issue I believe. Now it has a lot more torque and goes much longer ~1-1.5 hr. But might need to still upgrade the controller so that it will go even longer because it we have a few kids riding at the same time it overheats after a while (motor and controller). Now cables, F/R switch and solenoid all replaces with new HD versions as well as new batteries.

Two questions:

1) Would switching from 36 to 48 v in the future just add torque or also add distance before charge?

2) What controller would you recommend for aftermarket HD? Looking to replace the motor as well to upgrade in the future.

[JohnnieB]

1. Going from 36V to 48V will Increase both speed and torque by roughly 33%. Runtime/range is a separate issue.

How far the cart will go on a single charge is determined by the storage capacity of the battery pack. A standard 36V pack consists of six 6V-225AH batteries and stores about 8100Wh (Watt hours) of electrical energy, The typical 48V pack consists of six 8V-170AH batteries and stores about 8160Wh of electrical energy, so the range/runtime is roughly the same.

To get longer runtime you can get higher Amp-Hour 8V batteries or build the pack with eight 6V batteries rather than six 8V batteries.

I wanted a 30+ mile range for my cart and went with seven 6V 245AH batteries for a 42V pack that fits under the seat with a storage capacity of 10,290Wh.

Attached is a list showing the relative storage capacities for 48V pack made up from various 6V and 8V batteries.

2. Alltrax SR48400 or larger 500A or 600A versions depending on motor and tire height and type and terrain.
https://www.cartsunlimited.net/alltrax-sr-series--.html

[steven2020]

Thanks, Johnnie. Any word on when the ALLTRAX SR-48600 might be back in stock to order?

[JohnnieB]

Originally Posted by steven2020

Thanks, Johnnie. Any word on when the ALLTRAX SR-48600 might be back in stock to order?

Other than being a repeat customer, I'm not associated with Carts Unlimited.

You need to ask scottieb about when he'll get some more stock from Alltrax.

[steven2020]

Hi Johnnie/other form members, sorry to bother again. The cart just stopped working entirely. I ran some voltage tests on the controller/solenoid/batteries:

B+ and B- 38.2v
B+ and M- 37v
Positive controller to M- 37.1v
Positive controller to B- 38.3v
Positive controller to negative controller 0.1v
Positive controller to B+ 0.1v
Full battery pack ~37v
When F/R is engaged, there's no voltage in the controller or solenoid.

Other notes: when engaging the accelerator, I can still hear the accelerator micro switch in the floor click, when changing between F & R I can hear the F/R switch click but I can no longer hear the new HD solenoid click when pressing the accelerator. It has been breaking down after short distances again until it didn't work at all anymore. One other item to note, the white wire connector that plugs into the top middle portion of the controller, the white wire on the far right (I believe comes from the micro switch from the pedal) has been very loose in which I've had it tapped together, I just stripped it today, twisted the wires together and inserted back in to get a better connection but it didn't fix the issue - though where can I buy a new connector with wire clamps to push in - or just a new complete wiring harness? It's a 6 pin connector but just the right 4 have wires (from right to left, white, black, orange, red).

Do you think the new HD solenoid when bad somehow, new HD F/R switch, old stock controller or old stock motor?

Current setup:

Make: EZ-GO
Model: TXT 2006 Electric
Body Upgrades: Lift, large off-road tires, back seat
Batteries: Trojan T-105 6 volt T2 (new in 2019) - 6 of them
Controller: Stock Curtis PMC 25864G09
Motor: Stock A02-4012 36v AU2500 FLT SPD (2006)
Solenoid: New HD 400A/200A 36/48v Solenoid (replaced in 2020)
Diode & Resistor: New HD 36/48v (replaced in 2020)
Cables: Brand new 2g cables (all 13 replaced in 2020)
F/R Switch: New HD switch (replaced in 2020)
Accelerator micro switch and sensor: Stock/original

[JohnnieB]

If the solenoid is not clicking when pedal is pushed, that's the first thing that has to be fixed. Attached is a schematic with the solenoid activation circuit highlighted.

Also, unless otherwise stipulated, all voltage measurements are made with the Negative (Black) test lead connected to the battery pack's main Negative terminal.

[steven2020]

Thanks again, Johnnie. I'll look further into the solenoid. It has only been used lightly for a few months so I wonder what would have caused the short life if it is truly dead. I'll do more research and run more tests with the negative on the battery pack main negative terminal

[JohnnieB]

Originally Posted by steven2020

Thanks again, Johnnie. I'll look further into the solenoid. It has only been used lightly for a few months so I wonder what would have caused the short life if it is truly dead. I'll do more research and run more tests with the negative on the battery pack main negative terminal

The solenoid probably isn't dead, it most likely isn't getting the voltage on the small terminal with red wires needed to energize it.

[steven2020]

Luckily after tracing backwards a wire was loose on the white connector that plugs into the controller and a loose wire on the F/R switch. Last question for now, where would I find new wire connectors for the red/orange/black/white wires that plug into the controller? Works great until I get to upgrade the controller and motor plus add an extra battery to the pack.

[JohnnieB]

Part number for the complete "WIRE HARNESS (CONTROL)" is 73103G02.