I have a friend who is a mechanic at a golf course in New Hampshire, and he has to deal with the golf carts. He claims that the golfers abuse the carts by using two throttle positions: floored throttle and floored brakes. This is obviously abusive to the battery and [I assume] a regenerative braking system. Does anyone know of a circuit that will regulate the current flow out of the battery when a drunk golfer stomps on the accelerator, and also regulates the braking system to charge with max efficiency? They have to replace the batteries after about two years due to such abuse. It is a 48 v system; are there any more efficient batteries than lead-acid? That is, markedly cheaper than Pb-acid over the life-cycle?? Remember the temperatures in NH.
It should not be too difficult to add a time-delay ramp function to the=20 motor drive as controlled by the accelerator pedal. And a truly good = design=20 would monitor the battery discharge current and protect them from abuse. =
Maybe the thing to do is mount a "kill switch" under the accelerator, = which=20 responds to a forceful stomp and latches in the off position. Then = activate=20 a display which reads "You are too drunk or angry to drive. A nice walk = back=20 to the clubhouse will do you a world of good".
floored throttle and floored brakes. This is obviously abusive to the battery and [I assume] a regenerative braking system.
battery when a drunk golfer stomps on the accelerator, and also regulates the braking system to charge with max efficiency?
PB-acid batteries do not fail because of charging depth. Battery piles in telco installs last, SFAIK, forever.
What happens is that flakes of lead oxide fall off the plates ,build up in the bottom and short out cells. Long ago , people would dump out the battery, buy acid and fix them. They came with screws on the top.
That is, markedly cheaper than Pb-acid over the life-cycle??
Probably not. Maybe gel, but... probably not. It's easier to raise the golf cart rental price. They'll pay it...
floored throttle and floored brakes. This is obviously abusive to the battery and
[I assume] a regenerative braking system.
battery when a drunk golfer stomps on the accelerator,
Sure, there are breathalzyser gizmos that won't let you drive drunk. Put a brick under the accelerator. Maybe you just need a circuit that monitors peak current and logs it. Apply a "lead foot" surcharge to the rental. Make it a contest. Free rental to the lowest battery stress for the day.
and also regulates the braking system to charge with max efficiency?
Do you want maximum efficiency or minimum battery stress???
How has this abuse been linked to the symptom? Age kills batteries. Sulfation kills batteries if they're not charged frequently over the winter. Depth of discharge kills batteries.
That is, markedly cheaper than Pb-acid over the life-cycle?? Remember the temperatures in NH.
No.
Golf cart manufacturers know the demands of their customers and compete to best satisfy those demands. What does the cart vendor say when you ask them this question?
Golf course owners get big bux from rentals. Do you really want your customers going elsewhere cause your carts are wimpy?
Do you really want fewer golfers per day because you slow down their progress?
You used the right words...life-cycle costs...just apply that to the whole business. Your golf cart battery cost savings might be offset by other unintended consequences.
Golf is a lifestyle. Be careful how you screw up the "experience".
Don't discount the liability issue. If anybody ever gets hurt for any reason while driving your modified cart, you're gonna be in court... even if you couldn't possibly have been the cause. You lose even if you don't lose.
positions: floored throttle and floored brakes. This is obviously abusive to the battery and [I assume] a regenerative braking system.
of the battery when a drunk golfer stomps on the accelerator, and also regulates the braking system to charge with max efficiency?
abuse.
lead-acid? That is, markedly cheaper than Pb-acid over the life-cycle?? Remember the temperatures in NH.
I bet they buy the cheapest batteries they can find, if they are anything like the golf courses I've talked to. One was complaining about the high failure rate of their chargers, but they were trying to charge batteries with shorted cells instead of buying new batteries. The cheap SOBs were also replacing them one by one, instead of a full set of four new 12 V batteries.
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You can't have a sense of humor, if you have no sense.
I actually build progressive accelerator things for childrens electric tricycles but it is so a disabled child does not get thrown off.
The modification costs about $100 built by a volunteer and then fitting time. I don't think it would be very economical for a commercial golf course where the OP would not want the hastle of being the responsible party when the modified carts fail.
First idea is to install a "fuel gage" to log the amount of charge used. Something similar to the watt-hour log meters used on houses. Then just add a substantial energy surcharge to the golfers when they check in. Or if the watt-hours used is over a certain amount, eg 500 watt-hours then add a penalty fee.
Second idea is just to remove the ability to consume power when the brakes are applied. Or any interlock to prevent what you describe. If there is a regeneration system and it is properly designed, then your description of the problem would not be possible. I can't see how any responsible golf cart designer would permit the kind of abuse you describe.
** Bound to create hostile customers.
** Who said there was any ??
Braking a DC motor is only a matter of applying a short across the brushes - this in turn brakes the vehicle very hard.
** The point you missed is that if the braking function is applied HARD - then there is no regeneration of energy as the motor is shorted. In any case, it is a complete furphy far as battery life is concerned.
** There is NO serious abuse going on - the lead acid batteries are dying of too many charging cycles and old age.
The OP is clueless as are the golf cart mechanics he alludes to.
That was my first thought too... What he should have done was contact the cart manufacturer and gotten their advice, which I'm sure would be "There is no problem here..."
Being in NH myself, I doubt the carts are any more abused than carts at any other location.
Current and voltage vs time logging might help find out what is killing them. What would probably help is making it so that the batteries seldom get discharged into the last 20% of capacity regime where the weakest cells start to suffer permanent damage.
Although it is also possible that the batteries are being killed by over charging, poor maintenance procedures or running into them into ground too frequently. Similar problems afflict fork lift trucks.
They should still last about 3 years if looked after properly.
Hampshire, and he has to deal with the golf carts.
hrottle positions: floored throttle and floored brakes.
I dont see anything abusive about that, flat out is generally the only useful setting on electric carts.
aking system.
That seems most unlikely on both counts
ent flow out of the battery when a drunk golfer stomps on the accelerator,
The existing controller does that
ditto
rs
many likely causes, such as:
- fitting NP type batteies instead of golf cart or mobility ones, which are vibration proofed
- failing to recharge them as soon as they're low
- running them flat instead of half flat
- mixing new and old batteries in one cart
es than lead-acid? =A0That is, markedly cheaper than Pb-acid over the life-= cycle??
no, lead acids are as cheap as they get, hence their widespread use. There is one way to dramatically reduce costs, and thats to build a set of batteries yourself. Its easy enough to do, and theyre very cheap, but it does involve handling sulphuric acid and powdered lead compounds. You'd need to make gel or AGM batteries, not flooded ones, for safety & liability reasons.
"A nice walk back to the clubhouse will do you a world of good"... will get you sued by the handicapped golfer who is a millionaire and will now own your clubhouse ;-)
Last time I did golf cart controls was in the mid '70's with (car starter motor) relays...
I had an uncle in Sun City, AZ, who owned a golf cart shop. Over there they like to drive them on the street :-)
So I used a foot-switch under the pedal to apply a field shunt when floored... took you up to about 25 MPH ;-)
Now-a-days I would guess electronic controls... who knows what, but no where as reliable as relays. ...Jim Thompson
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I love to cook with wine. Sometimes I even put it in the food.
I'm not scared of stupid lawsuits and all that nonsense, but I would think twice about altering the electronics in a golf cart unless it's your own. It's not really something you'd want to test out on customers of somebody's business.
Electric wheelchair controllers seem to fall under the just don't mess with it territory.
Hampshire, and he has to deal with the golf carts.
hrottle positions: floored throttle and floored brakes. =A0This is obviousl= y abusive to the battery and [I assume] a regenerative braking system.
ent flow out of the battery when a drunk golfer stomps on the accelerator, = and also regulates the braking system to charge with max efficiency?
rs due to such abuse.
es than lead-acid? =A0That is, markedly cheaper than Pb-acid over the life-= cycle?? =A0Remember the temperatures in NH.
The solution is obvious:
The problem is not the batteries, it's the shitty golfers - the ones who can't make it to the pin in 3 or 4 swings. That would be me, in case you were wondering. ;)
They're the ones chewing through all those battery charges just chasing their slices, water hazards, constant back and forth searching for lost balls, and who knows what else!! Instead of a penalty fee for returning the cart with a dead, or nearly dead, battery, give 'em a free golf lesson!
I'm not sure if you can practically control depth of discharge. Is it better that a customer's buggy dies on them, or that the battery gets discharged some more - I'd say the latter is better.
The buggies should ideally be placed on charge as soon as they come back to base. Even if it only gives them an hour of charging between 2 uses, it improves the depth of discharge and thus improves battery life. This might mean spending on a bunch of expensive chargers. (There are cheap workarounds, but probably not worthwhile.) To maximise these charge intervals, a rota arrangement for the buggies could be implemented if its not already.
That is what I see in the golf courses around here. High current chargers hanging from the ceiling, and the carts are plugged in to one as soon as they are returned.
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You can't have a sense of humor, if you have no sense.
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