Rectangle lug on + batt ?

[Golferdave]

Did batt R&R on EZGO,
SOB , those 12v batteries are heavy

What is the black rectangle box on the black lug wire on the
+ batt?
Looks factory

[Golferdave]

Even with sw in "tow", key off, there was a little current
Had a little arc when remove first wire.
Any procedure, for which wire to pull first?

Old batts:

[BobBoyce]

That little block is a battery temperature sensor for the circuit board buried in a block of epoxy that is in the charger port. That 'wire' has 2 smaller wires in one cable. The battery terminals conduct internal battery heat to outside of the battery to be sensed.

Please keep it in tow mode when disconnection or reconnecting the batteries. That helps to prevent damaging the controller. I would disconnect the positive first and reconnect it last.

Bob

I do the negative main cable first and last

You Tube

You Tube

[cgtech]

I use a precharge resistor before & when making the last connection to prevent spark. Also, a lot of the spark is from the caps in the dc/DC convertor, you can Unplug it, then replug it last.

[Golferdave]

Been doing Neg lead first & last , but no real reason

Procedure for heavy equip was to disconnect - batt leads (typically 24v )
Caterpillar equip, switches the - (neg) lead, maybe just habit

Was told the rectangular block on the black wire was possibly a temperature sensor to shut off the charger if the + post gets too hot ??
Possibly a "bi-metal switch" ?

[Golferdave]

Originally Posted by cgtech

I use a precharge resistor before & when making the last connection to prevent spark. Also, a lot of the spark is from the caps in the dc/DC convertor, you can Unplug it, then replug it last.

Which plug is it?

[meimk]

I think what Golferdave is getting at is that as long as you are key off & switch in tow you should be fine. Under those conditions you're not going to spike your controller, which is the issue. The power converter is going to cause a smaller spark no matter where your final connection is. Shouldn't be an issue.

[tag50]

Originally Posted by cgtech

I use a precharge resistor before & when making the last connection to prevent spark. Also, a lot of the spark is from the caps in the dc/DC convertor, you can Unplug it, then replug it last.

For those who don't have a pre-charge resistor laying around, a regular household light bulb will have the same results.


.

[cgtech]

The black box is a thermal diode, it's resistance changes with its temperature.