builing an electric go kart from an old electric golf kart and have a few questions...
hello, this is matt and i just registered here cause i am just getting into building electric vehicles. right now i am on the verge of using the batteries and motor from an old golf cart to build an electric go kart. my friend really wants to sell it, whereas i think it would be a much better idea to turn it into a go kart. i am unsure how exactly an electric vehicle operates and what certain devices do in the golf cart, so im searching for info.
first of all, heres the specs on the golf cart:
cushman golfster cart we think thats maybe 15-20 years old
36 volt G.E. series motor
six 8v batteries (we were told they were a year old)
old-style speed control (three different speeds controlled with resistor coils)
it has a black box with six wires going to various places, and i looked up the model # which says its a relay. i am unsure what this does.
it has a 36 volt solinoid
questions about the golf cart:
1. is the motor running on 48 volts? or does the solinoid limit the voltage to 36 volts? (what does the solinoid do, and if we got a 48 volt one would it speed up the motor to 48 volts?)
2. when we charge the batteries with the included 48 volt charger, the batteries bubble quite noticeably. the charger usually cuts off only one hour to 3 hours into charging and reads, "abnormal cycle." what could be the possible problems with the batteries and/or charger? is there a way to fix this?
i would like to get the batteries charging well and in the best condition possible before thinking about using them for the go kart.
questions about using everything for a go kart:
1. what would we need to set up a throttle and a speed controller for a low price?
2. how fast could we get our go kart to run without burning the motor?
3. if the motor is not already running at 48 volts, how would we allow 48 volts to go to the motor, and if that would be ok?
4. is it possible to set up regenerative braking without spending a lot of money, and how would we go about that.
im sorry for all the questions, thanks so much to anyone who gives input. i am really excited to make this thing, its just i have a lot things to learn before i do.
6*8 = 48 .. right? Therefore the volts at the motor is 48. Go to radio shack (or equivalent) and get a voltmeter.
A solenoid is like a switch. It has a coil which, when energized (has current running through it), closes the switch. It's a way to control a large current using a small enough current to go through a keyswitch so that you can easily have a key to turn the thing on and off.
The batteries might not be good. The voltmeter will help you. For example the cart may have sat for a long time with the batteries not being charged, and when lead-acid batteries sit uncharged they tend to sulfate.
1. Get the voltmeter.
2. Do all the batteries "bubble" equally?
3 When they are bubbling, they are producing HYDROGEN GAS. One spark and your whole day can be ruined. You may also loose your eyesight in the explosion.
4. Have the batteries individually load tested after they are fully charged. read this; http://leadacidbatterydesulfation.yuku.com/directory
5. You can use all the components from the golf cart to make the go-cart without buying anything additional.
If your 6 batteries, of 8 volts each, are correctly series wired, they will provide a 48 volt supply to the motor, regardless of the solenoid markings. Get a good DIGITAL VOLTMETER (RADIO SHACK?)and measure eachbattery carefully. At full charge, each 8 volt battery should measure about 9 volts, or around 56 volts for the 6 in series. If any cell, (There are 4 cells in each battery) is bubbling differently, that battery is possibly bad. Wear eye protection when around such batteries, ESPECIALLY if they are bubbling, as bubbling releases explosive hydrogen and oxygen gases, and any SPARK can ignite them, causing an explosion, with acid being sprayed eveywhere!--Do not tamper with the battery wiring, or do anything to make a spark near or above the batteries when charging and bubbling! (If your batteries are series-parallel wired, total voltage will be 24 to 28 volts instead, and the 48 volt charger would be incorrect for that application)--Wire them in SERIES for maximum speed! It is also possible that the large relay, with 6 wires, if they are large heavy guage wires, may be arranged to SWITCH the batteries from series to series-parallel.---Switch to SERIES (48-56 volts) for charging and high speed, switch to series-parallel (24-28 volts) for slower speed/long distance.-i HOPE THIS HELPS!-Bob Curry
Come to think of it - the large relay may be a forward-reverse contactor. Switching between forward and reverse might be a switch on the dash that causes a contactor to flop connections around between the motor and controller.
I would say a definite need to take voltage and polarity readings exists, so as to resolve the battery status, as well as the function of the large relay and other components. Do you have a digital voltmeter yet?--(They can be obtained relatively inexpensively)--Bob
If you truly have 6 identical batteries, and they are lead-acid type having 4 series cells in each battery, they should be charged to about 9 (NINE) volts each! Charging to 8.1 volts is only perhaps 50-60% charged, for such batteries using normal lead-acid chemistry. Will you please describe the batteries in more detail? How many filler caps, or vents, are on each battery? What brand are they? (Who made them) It seems that something is not right, with the charger/battery arrangement.--Bob