Advice on electric golf carts

[3RRL]

Eddie,
Having a golf cart is really handy. I have 2 and will bring both of them up to my rural property when I move. Get the 48v system too. As a suggestion, most golf courses replace their fleet every 3 years as mentioned. My club sells them for $1,500 and they are in great shape. They trade off between Club Car (like mine) and EZ Go. The traction on a regular stock golf cart is great and you may not need to modify it. Here is a picture of mine in the background at the golf course.
That's me standing next to the blode dude who happens to be John Daly. I played several tournaments with him when he visits here. The guy on the left (walking away) is my son Matt who injured himself in the solar thread and the guy standing by my golf cart is my oldest son Aaron (8yrs Marine Corps)



Hope you don't mind me sharing that picture Eddie. I have lots of them with my sons and John Daly.

 

[patrick_g]

Eddie, My sister bought a used cart several months ago to use at a mountain resort with serious hills (nicknames like Cardiac I and Cardiac II) she didn't opt for the high power mods and says it worked fine with minor grades at home (Wickenburg, AZ) where my BIL drives it to and from the golf course as well as on the golf course but... It also worked real good in the mountains with all seats occupied by real sized people. She is super pleased. They commute in a 3/4 ton diesel Dodge with the cart in the bed. Once in the mountains (6 months in mountains, 6 months in S. AZ) she says that they hardly ever start the diesel. They have a sun top which is very useful and a canvas/flexible plastic suround that they don't use. We'll see how that goes if they get caught out in a thunder storm.

IF $ is not too tight, get the 48 volt. Trojans are good cart batts. Although I haven't owned a cart I have used several 6 volt Trojan cart batteries (220 AH size) and found them to be good stuff. There are other brands I have used but none were a better deal (function/price.) Try to get a charger designed for cart batteries, preferably new technology that won't overcharge (good float function) and skip the timer type. They work, just not as convenient and prone to over or under charging if yoiur estimating ability is not what it should be. Over and under charging have economic penalties as well as performance penalties.

Don't undersize even the automatic charger, trickle charging isn't the only need for good battery maint.

Note to 3RRL: I guess lately John has been pretty much a rehab (so far as I know) success. Whenever any of us think we have problems we can't handle, think about his comeback.

Pat

 

[SPYDERLK]

Do these gauges usually come with instructions or is it necessary to have some understanding of how things work; I'm good with instructions but DC power is way out of my area...

Its mainly mechanical. Mount it. Electrical hookup is attaching one wire to each end of the battery string, observing correct polarity. Only two possibilities - if wrong the needle indicates negative - just reverse it and youre done. You always have a visual health check on your batts.
Larry

 

[stump54]

Its mainly mechanical. Mount it. Electrical hookup is attaching one wire to each end of the battery string, observing correct polarity. Only two possibilities - if wrong the needle indicates negative - just reverse it and youre done. You always have a visual health check on your batts.
Larry

When you say "battery string" do you mean Negitive (-) on first batt in line, and Positive (+) on the last?

 

[SPYDERLK]

When you say "battery string" do you mean Negitive (-) on first batt in line, and Positive (+) on the last?

Yes. The batteries will be in what is called a series string. Each batterys + will connect to the next batterys -. Like in a flashlite. This adds the battery voltages together giving a battery pack of 36V (6 six volt batteries) or 48V (8 six volt batteries). Hooking the leads of your meter to opposite ends of the pack as you have described, will measure the total voltage of the pack. The voltage will be highest when charging and lowest when running the cart up a hill. For a 36V pack you will see around 45v at end of charge. After charge the voltage will quickly drop to about 40V and then after several hours settle to about 39V. When you then drive the cart the voltage will drop to 36 or lower. Under heavy load climbing a hill it may go as low as 30 even if the batts are fully charged. When you stop tho, the V will jump right back up to 38 or 39. As the pack becomes more discharged you will see this characteristic change. Youll quickly begin to recognize the signs that it needs a charge.

 

[stump54]

I put the gauge in today. Not a hard job except gaining access to the back-side of the dash. Thanks for the explaination.

So if you add accessories such as: radio, horn, lights etc are they connected the same?

 

[SPYDERLK]

I put the gauge in today. Not a hard job except gaining access to the back-side of the dash. Thanks for the explaination.

So if you add accessories such as: radio, horn, lights etc are they connected the same?

Sort of, but not exactly. You will have to connect to the proper # of batts to give you the voltage needed by the accessory. I believe the ones you mention will turn out to be 12V devices. For them you will only connect across 2 adjacent batteries in the string, rather than the whole string. Some attempt at balancing the load is good when you have accessories that only use part of the string. This is because the accessory causes increased drain on the battery(s) it is connected across. So, you have a situation where for example your cart motor is drawing 20 amps from the entire 36V pack and your lights are drawing 4 amps from just 2 of the 6 batteries. These 2 out of the six are supplying 24 amps while the others are just supplying 20. These 2 batteries are discharged more quickly, therefore they are deader than the others when you start to recharge. The charger connects across the whole pack and charges all the batteries at an equal rate (same amps). The ones that had the lower current drain reach full charge more quickly and then are overcharged for a while before the deader batteries come up to a high enuf voltage so that their contribution summed with the others reaches 45V and the charger turns off. The deader ones havnt quite got a full charge, and the others are overcharged. This is neither terrible nor good, but to be avoided where feasible. If you will be doing a lot of accessory use, like running the radio all day or the lights several hours per charge, you could supply the 12V from different pairs of batterys at different times. That would entail a setup to conveniently move the accessory supply wires from battery to battery at your discretion. This would help prevent the batteries in the pack from becoming mismatched - much in the way tire rotation lengthens the life of a set of tires.
Larry

 

[stump54]

Sort of, but not exactly. You will have to connect to the proper # of batts to give you the voltage needed by the accessory. I believe the ones you mention will turn out to be 12V devices. For them you will only connect across 2 adjacent batteries in the string, rather than the whole string. Some attempt at balancing the load is good when you have accessories that only use part of the string. This is because the accessory causes increased drain on the battery(s) it is connected across. So, you have a situation where for example your cart motor is drawing 20 amps from the entire 36V pack and your lights are drawing 4 amps from just 2 of the 6 batteries. These 2 out of the six are supplying 24 amps while the others are just supplying 20. These 2 batteries are discharged more quickly, therefore they are deader than the others when you start to recharge. The charger connects across the whole pack and charges all the batteries at an equal rate (same amps). The ones that had the lower current drain reach full charge more quickly and then are overcharged for a while before the deader batteries come up to a high enuf voltage so that their contribution summed with the others reaches 45V and the charger turns off. The deader ones havnt quite got a full charge, and the others are overcharged. This is neither terrible nor good, but to be avoided where feasible. If you will be doing a lot of accessory use, like running the radio all day or the lights several hours per charge, you could supply the 12V from different pairs of batterys at different times. That would entail a setup to conveniently move the accessory supply wires from battery to battery at your discretion. This would help prevent the batteries in the pack from becoming mismatched - much in the way tire rotation lengthens the life of a set of tires.
Larry

Surprisingly, I think I understand that...
You mentioned earlier about an inverter. I know some simply plug into a lighter socket; so would the wiring be similar to what you described for the lights? For that matter, would a lighter socket work if all accessories are occasional use?

 

[SPYDERLK]

Surprisingly, I think I understand that...
You mentioned earlier about an inverter. I know some simply plug into a lighter socket; so would the wiring be similar to what you described for the lights? For that matter, would a lighter socket work if all accessories are occasional use?

Yes, wiring would be the same for an inverter. However, if you are talking about an inverter to do real work with, you will need a bigger one than a lighter socket can supply. Power = Current X Electromotive force, ie. P=IE - - an easy acronym. So, for a typical 400W hand drill - - 400 = Ix12, I = 400/12, I= 33 Amps from the battery pair you are using to supply the inverter. Youll notice that since you are using 12V to produce 120V you must supply 10x the current. A reasonable rule of thumb would be to multiply the nameplate amps on the appliance by 11 to account for the inefficiency in the conversion. You draw about 11x the nameplate amps from the battery.
These level drains should either be fairly brief, or else must be rotated battery to battery to prevent significant discharge relative to other batts in the pack.
Im not sure if youre asking whether all accessories could be run from a lighter socket, but - - yes, except for an inverter above about 200W.
Low level occassional drains should not warrant battery rotation.
This is reminding me why I used 3 gauges tho.
Larry

 

[StevenPaul]

SPYDERLK,

I think you just answered a question I just posted, but I was wondering if you could either post or email me a "how to" wiring diagram for those accessories (lights, radio, heater/fan, inverter, gauges, etc.). I have a 36 volt 70's model Cushman and it runs great. I just need to add a few things and I don't know how.

thanks again!
Steve