No - this isn't about improving the quality of your golf to electrifying levels. It is about battery motorised golf accessories, battery motors and control systems. I don't want to get technical - but more and more people are using motorised golf caddies and buggies. Chosing one is a technical area and a little knowledge before you buy can save a lot of trouble later.
One of 4QD's principal markets is ride-on golf buggies. Now there is a different market for buggies in UK as opposed to the USA. Most American machines use petrol engines and the buggies are two or more person vehicles. There are a few electric ones, but petrol is certainly more common. For the most part the electric ones use series-wound motors (in FAQ page) which are less efficient than the permanent magnet motors used on most British machines. Unfortunately PM motors are usually smaller than series wound so are used mainly for the smaller vehicles (one man ride-on machines) - which this page aims to cover.
You may think that a buggy is little more than a chassis with three or four wheels, a couple of batteries, a motor and a seat. You would be wrong: many small companies start up thinking that things are this simple. It invariably seems to take them at least a year of trial and error to get a vehicle which steers properly, isn't unstable and handles correctly.
Buggies range from small, lightweight three wheelers up to more substantial four wheelers. The three wheelers are usually lighter, so are easier to get in and out of your car. Unfortunately they are also likely to be worse at getting you and your golf clubs up a steep hill. The smaller, lighter weight buggies also tend to be less stable, they can tip over backwards if you accelerate too sharply, especially on a hill.
Now one of the misconceptions people have (in the UK at any rate) is that golf buggies are for invalids or (to be kinder) the elderly. True - this is one of their target markets but it should not be. Golf buggies can be great fun! My own son (10 at the time) used to have a great time driving a golf buggy around our back garden. And on a golf course they are a great pleasure to use - even for the able bodied. One problem here is that the youngsters like to drive them fast and furious - this is definitely not encouraged by the course management! However one man golf buggies are best viewed as recreational vehicles - not as mobility aids. Bear that in mind when chosing and you may alter your sights!
The controller rapidly switches the battery power to the motor on and off. Typically the battery voltage is applied to the motor 20,000 times per second in a series of pulses. If the 'on' time is equal to the 'off' time then the 24v battery is connected to the motor for 50% of the time, so the motor is fooled into thinking it only has 12v across it, so it runs at half speed. If the pulse (the on time) is wider then the battery is connected for more than 50% of the time, so the motor has more voltage across it. With a narrow pulse, the voltage is reduced so that, by varying the width of the 'on' pulse (hence Pulse Width Modulation), the average motor voltage can be adjusted between zero and full battery voltage, varying the motor speed.
All quite simple you may think - except that to get a 15 stone man on a golf buggy up a 30% hill at 8 mph may take 100 amps or so. Electronically 100 amps is a lot of current and takes a lot of switching. Another problem is what happens if you get a wheel stuck. A pair of motors which can take 100 amps for a minute or so to get you up the hill might take 300 amps or more when stalled. If the controller isn't designed properly this overload current will destroy it so if you want to be really unpopular when taking your buggy for a test drive, try stalling it - run it up against a brick wall and put the throttle on full. The control system must be able to take this.
A good controller will have what is called 'Regenerative braking'. When you brake your car hard the brakes get very hot as they dissipate the car's energy during the braking. An electric motor can however also be used as a generator and a good control system will use this fact to brake the vehicle. Instead of wasting the energy as heat, the controller tries to pump it back into the battery to save energy. The process isn't very efficient, but some energy does get saved. More importantly it does give you single foot (or hand) pedal control operation of the vehicle. In a machine with regen braking you will find than you don't use the mechanical brake: in fact some manufacturers do not even fit one. We always recommend to our customers that a mechanical brake be fitted as a back up safety device. Better to have an extra brake and not need it that to need one and not have it.
Then there is an electromechanical brake .... another 'buzzword'. Some vehicles have this - others do not. A motor can only act as a generator when it is actually turning. The faster it is turning, the better it is at generating, so the harder it can be used as a brake. The opposite of this is that the motor is no good as a brake at zero speeds, so if you park your machine on a hill it will gently roll off downhill when your back is turned. To stop this, motor manufacturers can fit an electrically operated brake onto the motor. This is a small disc brake operated by a spring and held off by the controller applying 24v to an electromagnet to release the brake when it is operating. The controller removes power from the brake magnet after it has reduced the vehicle speed to zero, parking the motor.
This mainly depends on your weight and the 'hillyness' of the courses you use. If it is a struggle for you to get up a steep hill (or you wouldn't be looking at a buggy). The steeper the hill, the harder you (or the buggy) have to work. The heavier you are, the harder the buggy must work. So if you are an overweight 18 stoner don't look at small, lightweight, low performance three wheelers. They won't cope. On the other hand if you are a mere 8 stone, then a small vehicle will do nicely. But make sure you try it out on a steep hill. If the buggy is too small for you it will loose speed on a steep hill. If it sails up the hill without any sign of a struggle - then it is OK - but make sure you have you normal full set of clubs aboard also..
If you want to pack your buggy in the back of a car, you will go for a small one, usually a 3 wheeler. Unfortunately these are the most likely to tip over backwards, especially if you have a heavy golf bag on the back, so try it out by stopping on a steep hill and then re-starting. Careful though, if the vehicle is unstable you may end up on your back in the rough! Also try the vehicle going sideways across the hill to see if it it unstable here. If the vehicle is stable you will fall off the seat well before the vehicle tips over!
Of course, if you play with friends, you will probably want a machine with a nice high seat. Problem - the higher the seat, the higher the centre of gravity and the less the stability. The smaller the vehicle, the lower you will need to sit for stability. 4 wheels are usually more stable than 3 and a long, wide 3 wheeler will be more stable than a short, narrow one. Make sure the batteries are well forward so the centre of gravity is near the centre of the machine - a heavy golf bag on the back can make a bad machine tip over backward if you accelerate fast up a steep hill.
Some vehicles, especially those by new manufacturers, tend to have very poor steering. I have seen a vehicle (which was on sale) where on full lock one wheel went off at right angles and the machine locked up. Also, with a three wheeler, does the front wheel hit your feet when you go to full steering lock.
Most golf buggies do have reversing. Manufacturers seem to thing they cannot sell a vehicle without reverse. However, how often will you use reverse on a golf course? A controller with reverse is about twice as expensive as one without and this will add to the machine's cost. However, most machines do have reversing whether you want it or not (we should complain - we're making more money on the controllers). If they do, then try the effect of operating the reverse switch when you are travelling at full speed. Some inferior controllers cannot take this and will blow up. Our reversing controllers have what is called 'dual ramp reversing': when you operate the reverse switch at full speed the controller will slow to a stop (at a preset, and adjustable, deceleration rate) then start up backwards, under full and safe control at all times.
Electronics and water do not mix: if the controller is mounted in a bad position and you drive through a puddle - or even on wet grass - the controller will get splashed. There is one machine of Polish manufacture which has the controller mounted very low, between the back wheels. If water gets splashed into the controller failure is very likely. The controller should in any case be adequately splash-proofed. Another point to watch is the wiring. What will happen if water drips onto any exposed cables (for instance the wire connecting the handle-bar controls to the main controller). Will the water run down the cable and end up inside a connector, or even in the main controller?
These, unfortunately, are the weak link of electric vehicles. The batteries are not the same as car batteries. Car batteries are designed for a short, hard blasting (when you start the car) and a fairly quick recharge after which they are kept topped up to a sensible charging voltage by the car's regulator. A battery for an electric vehicle is different because if is going to be steadily discharged then slowly recharged, going through a cyclic charge-discharge process. They are therefore sometimes called 'traction' batteries or 'deep discharge' batteries. They are more expensive than car batteries. They also have to be treated very carefully: dischargingthem too far can damage them as can overcharging them. You also must not leave them discharged for any length of time, but should recharge them as soon as possible after use.
Some sort of battery voltmeter or Battery Condition Meter can be useful to tell you the charge left in them (4QD's LED BCMs). The problem is that the batteries loose their capacity steadily: each time they are used they will accept slightly less charge on the next occasion. So there is going to come a time when a set of batteries which used to get you easily round the course indicate a low charge at the 17th hole. What do you do then? Many buggy manufacturers find than a low battery indicator causes more worried customers than it cures, so do not fit them. If you do have one fitted it will probably dip as you go up a hill. If you know that this hill always causes a certain dip, but today there is more dip, then your batteries are probably on their way out, so the indicator can be useful.