Ground connection for dash voltmeter

[venahaks]

Neighbor's TXT with sketchy batteries, on a 6A charger...

I happen to have a nice panel-mount digital voltmeter that reads the batteries properly. However, I want to mount it in the DASH. +36V was easy (at the switch), but I cannot find a suitable ground.

Please don't tell me I must run a new wire all the way back to the batteries!

ALSO - at what indicated voltage should she turn around and head for home?

Thanks, gurus...

[Newbuggyboy]

This was in my ex-ray speedometer documentation:

DC Warning:
A warning can be set to alert the operator when batteries are below
this setting flashing the Yellow LED. Check with your battery
manufacturer specifications. The following is general guidelines
for LEAD ACID batteries:
12V Battery: Warning 10.5-11.0V (Gas vehicles)
24V Battery: Warning 21V
36V Battery: Warning 31.5V
48V Battery: Warning 42.0V

DC Danger
As batteries are depleted below a certain voltage, damage can
occur. DC DANGER Level can be set to alert the operator the
batteries are below this setting flashing the RED LED. Both the
Yellow and Red LED will Flash. Check with your battery manufacturer
specifications. The following is general guidelines for
LEAD ACID batteries:
12V Battery: Warning 9.75V
24V Battery: Warning 19.5V
36V Battery: Warning 29V
48V Battery: Warning 39V

[venahaks]

THANKS!
Now... where can I find a ground without disassembling the machine!
I pulled the keyswitch panel, but everything accessible seems to be floating.

[Timberwolflt]

Gotta run a wire back to the pack or controller... no frame ground on these... or as I’ve been told... no ground... more correctly... negative... B-

It’s not too big a problem... just route another wire back to the pack in the existing harness loom

[Timberwolflt]

I went ahead and mounted a fuse block up front so that i’d have 12V B+ and B- up there for whatever I might want

I’m not sure about the above voltages but 36.3V is 50% charge and you really never want to dip below that if you don’t have to... I rarely let mine dip below 37V

[rockfordpi]

Originally Posted by venahaks

THANKS!
Now... where can I find a ground without disassembling the machine!
I pulled the keyswitch panel, but everything accessible seems to be floating.

Old habits die hard, but I try not to allow myself to use the term "ground" when dealing with electric carts. I always try to refer to the other end of the circuit as "main negative". That helps me clearly make the switch from gas to electric in my brain.

[cgtech]

There shall be no "ground" on electric golf carts! That was one of my first lessons! Just dont do it. Too much risk of a meltdown. Run a wire back.

[venahaks]

Strange...
So the State of Charge and Voltage meters require independent B+ and B- wiring back to the battery pack? Why not just run a wire from B- to chassis in the back, and from chassis to the dashboard in the front? That new wire would have the advantage of being at no potential above ground, and therefore creates no fire hazard.

I just looked again at my neighbor's EZ-GO. The solution might be to add a small weatherproof terminal block in the battery compartment, add a fused 18ga wire from the + and a wire from the - to that block, then run a well-insulated and protected twisted pair under the machine to the front panel. That's extreme for a gauge that draws microamps and shouldn't be necessary, but this is my first exposure to such a machine so everything is new.

[cgtech]

Meh, do what you want

[R.Boyd]

Suppose you do that, then the positive lead to your motor rubs on the battery tray until the coppers is in contact with the tray that's bolted to the frame. What do you think will happen. Or any positive wire from the pack comes into contact with the frame. Sometimes we are our worst enemy.

Originally Posted by venahaks

Strange...
So the State of Charge and Voltage meters require independent B+ and B- wiring back to the battery pack? Why not just run a wire from B- to chassis in the back, and from chassis to the dashboard in the front? That new wire would have the advantage of being at no potential above ground, and therefore creates no fire hazard.

I just looked again at my neighbor's EZ-GO. The solution might be to add a small weatherproof terminal block in the battery compartment, add a fused 18ga wire from the + and a wire from the - to that block, then run a well-insulated and protected twisted pair under the machine to the front panel. That's extreme for a gauge that draws microamps and shouldn't be necessary, but this is my first exposure to such a machine so everything is new.