84 ezgo 36v left for dead..

[kgsc]

If you have any cart dealers nearby go see them. May have some used that you could pickup cheap.

[HandyRANDY]

Originally Posted by bronsonj

In my mind the resistor coils should be fine at a higher voltage. A little more jerky, but should be OK.

But, The entire resistor coil pack is replaceable, brand new, for $56... I'd put four 12v batteries in there and give it a go!

Congratulations on the cart! Are you going to keep it lifted like that, lower it back to stock height, back seat, etc?

I had a mid-80's marathon electric (it was an 87 I think?) that I put a 212cc Harbor Freight motor in with a gokart torque-a-verter and it hauled butt! Good luck on the build and have fun!

Thank you!
I like how parts are very affordable for this thing. I have the coil pack and solenoid on my favorites bar just in case!

Can you tell if this thing lifted compared to stock? I noticed the little 2 inch blocks but thought they were original. I found a 5 inch block lift kit on amazon for $70 gonna order it.
Also planning 2 inch spacers for the front wheels for $60 the pair and 22 inch wheels that will fit my stock rim for 40$ each.
I will be reinstalling the back seat no foot rest, reinstall roof rack but thinking tinted plexi for the top instead of the original top. New skins on the seats and backrests, front/back led light bars, stereo, police siren and PA system, new floor up front, and possibly a cheap steering wheel.

[cgtech]

Stock electrical parts are put under much heavier load when bigger tires are added. Stock 36v electrical parts are also put under 33% heavier watt load when upping to 48v. See where this is going? You are building a cool, fun little buggy, that will be breaking down all the time.

If you do stay with stock resistor coils (36, or 48v), try to spend as little time as necessary in the lower speed steps, to reduce heat. And no "slowest speed cruising". This does NOT mean "immediately slap the GO pedal to the floor", that's just as bad on other components in the system. Also, stay out of tall grass, they are known for lighting the grass on fire.

And it definitely has a (looks homemade) lift on it already, looks like 4 to 5" lift, but it still currently has stock size tires.

I have seen (and done myself) stock resistor coil to 48v "upgrades". On stock tires, the ones in good shape last a little while, the more-worn-out ones lasted less than a year before trouble appeared. This was done in cases where they said "we will barely ever use it, and we listened to what you said about getting out of the lower speeds".

[bronsonj]

Originally Posted by HandyRANDY

Can you tell if this thing lifted compared to stock?

Originally Posted by cgtech

And it definitely has a (looks homemade) lift on it already, looks like 4 to 5" lift, but it still currently has stock size tires.

As CGTech said, it absolutely has a lift already. If you do go with the four 12v marine batteries they won't last very long and you won't get good range, but it'll work. They make 12v golf cart batteries which are better than marine but not as good as six 8v golf cart batteries.

If you put bigger tires on the cart it will be harder on your electrical system. For a play cart like you are wanting to build I would stick with stock size tires. If it were me I'd lower it back down to stock height. Paint the rims black and put baby moon hubcaps on it. Four 12v golf cart batteries to get 48V but not as heavy as six 8v and buy a spare set of resistor coils.

Eventually you'll want to upgrade to a solid state controller, but for $56 you have the spare part for the component that will fail.

It's hard to cheat the iron triangle of cheap, fast, reliable. You can get two of the three sides, but it's neigh on impossible to get all three.

[HandyRANDY]

Understood! Thanks guys for the great input. Keep you posted!

[DickB]

Originally Posted by kgsc

Not sure how the coils would behave but higher voltage lowers current correct so wouldn’t heat be less ? Just asking. Also at full throttle do the coils even come into play ? Don’t know much about the toaster carts.

I'm not a cart expert - new to this myself. I am an electrical engineer.

All things equal, a 48v SYSTEM will draw less current than a 36V SYSTEM. But if you do nothing to the SYSTEM except increase voltage, current will increase. That's Ohm's Law.

The resistor coils are capable of dissipating only so many watts. At higher voltage with the same motor they will be dissipating more heat. The question is how much additional power can they safely dissipate, and for how long?

It is not clear to me why you want to jump from 36 to 48 volts. That seems inconsistent with your intended use.

[cgtech]

Originally Posted by DickB

All things equal, a 48v SYSTEM will draw less current than a 36V SYSTEM. But if you do nothing to the SYSTEM except increase voltage, current will increase. That's Ohm's Law.

I been trying to explain this forever. If you upgrade to 48v, AND dont ever use the newfound torque & speed, it might be more efficient. BUT, as we all know, if more torque & speed is available, it WILL be used. Resistor coils dont really offer this benefit for increasing efficiency when changing to 48v, because it burns power like it's at 100% throttle no matter what the pedal position is (excluding the OFF position).

[HandyRANDY]

Update!
Wired everything up for testing. I ran one 12v battery and it moves and steps up real nice. Serviced the brakes and kicked some rust off. I ran all 4g motor cables and have 2g for the batteries loop. Quite a bit to go with the body.....
I do have one question. Will the existing 36v solenoid operate at all with 12v? I only hooked up the one battery to the solenoid and throttle switch loop but got nothing from it. I tested resistance on the micro switch for the throttle and it looks good. Does the solenoid require higher voltage operate? Should I aleast get a faint little "click" of 12v? If so I dont. I bypassed the solenoid to test the rest of the cart with a jumper from one side to the other and used my f and r switch to complete the circuit to scoot around.

I want to go 48v simply to give it that little more. If I can squeeze 2 to 3mph more out of that old motor I'll be stoked... I dont mind changing parts to maintain that. I upgraded my daughter's power wheels from 6v to a 12v jet ski battery and loved it. That thing was run continuously and lasted a few years with that set up. I like to test different things and see how they work out. I'll start with the 36v while I finish the build. I will be running 3 12v gc batteries for now. Soon as things get rolling we'll mess with th 48v set up, and a dedicated 12v distribution block for all the goodies.....thanks for the input keep it coming.

[kgsc]

Not sure why you made that jumper cable for the solenoid when you could have just moved one the wires to the other lug but whatever. Glad you got it going.