Friday, March 4, 2016

Passion Gadgets Electric Scooter Service Center


iPassion Group Pte Ltd (Reg No: 201511854Z)
Singapore Address:Electric Scooter Service Center & Collection
Leong Huat Building, #05-08

6 Harper Road, Singapore 369674
(1 min walk from Tai Seng MRT )
(See map here)
Opening Hours:
Mon - Fri: 10am - 7pm 
Sat - Sun: 10am - 6pm  
(Public Holidays Closed)
Contact number:
General Enquires: (+65) 9181 - 4105 (SMS/ whatsapp only)
Scooter Enquries: (+65) 8161 - 6271 (SMS/ whatsapp only)
Email: Shop@PassionGadgets.com
More info:
LiveChat at our Website
WhatsApp/SMS: (+65) 
9181 - 4105
Mode of Purchase:Store walk-in: Viewing and self collection only.
Normal mailing via Singapore Post.
Registered mailing by Ninja Van. 
Home Delivery Service by Ninja Van (Doorstep Delivery)For Oversea orders: We ship internationally.
_________________________________________________________________________

Thursday, April 9, 2015

Diagnosis of Electric Bike and Scooter Problems

Weak (or Dead) Battery


Introduction
If you are experiencing poor battery performance (charging problems, slow speed, low range, etc.), there may be a simple cure. In some cases, the "push-on" battery connectors are quite loose as they come from the factory. This loose connector problem can cause any of the above mentioned difficulties as well as intermittent operation or losing power after going over bumps. If you have experienced any of the above problems, spend a few minutes tightening these battery connectors. Open the battery compartment and remove the push-on connectors from each battery ONE AT A TIME. Using pliers, squeeze the connector to improve its tightness, and reinsert onto the battery tab. If you still have problems, read on.
Battery capacity can be visualized by thinking of three glasses that are all 5" tall. The first is your new battery and is a fat 4" in diameter with about 64 units of "juice". The second glass is only 2" in diameter so it can only hold 16 units of "juice" when fully charged. The last glass, a mere 1" in diameter, can still be filled/charged up to 5" (13.5 volts), but it only holds 4 units of "juice".
New batteries are "stiff". Usually 3 charge/discharge cycles bring new batteries to 90%+ of their full capacity.

Symptoms/Causes
Symptom: LEV doesn't go as far on a charge.
Cause: weak battery
As an LEV's batteries weaken, they lose voltage quickly. If starting voltage is above 12.5 volts but drops to 11.8 volts after a short distance, the battery is weak. The fact that a battery seems rejuvenated after a rest is typical for batteries in all levels of discharge; they all have a recovery capability.
If a multiple-battery pack (standard on 24-volt LEVs), has one strong battery and one weak one, replace both promptly because:
  • Overcharging of the weak battery could occur leading to overheating, fire, and toxic gases.
  • Retaining the weak battery will limit range and speed - and lead to cell-reversal and drastically worse performance.
  • For best long-term results, batteries must be balanced; that strong battery won't likely be as strong as a new one.
If your LEV's batteries have provided a year's use and only lost 25% of their range, you have gotten your money's worth.
Sealed Lead-Acid (SLA) battery voltage should vary only about 15% over and 10% under the nominal voltage. When fully charged, a 12-volt battery should read 13.2 volts. When discharged, it should still read at least 11.8 volts -- if you want to get hundreds of charges.
Symptom: Sizzling battery sound when fully charged
Cause: Ending voltage is too high
Smart chargers switch their voltage down when fully charged to comply with battery manufacturers' stated "maintenance" voltage of about 13.8V. (27.6V for the pair). The sizzling sound says your charger is staying at the "cyclic" max charge voltage. That's a battery killer over time.

Testing a Battery
Visually inspect for obvious problems like damaged case, corrosion, loose hold-down clamps or cable terminals.
Here are three ways to test a battery:
  1. Perhaps the easiest method for checking batteries is to measure the voltage after charging, and then again after several hours. The voltage should not drop more than a few tenths of a volt.
  2. Another test is to fully charge the batteries, let them sit over night, and charge the next morning. If the charger doesn't go green (indicate fully charged) almost immediately, your batteries are weaknening. The longer it takes to charge after sitting over night, the weaker are your batteries.
  3. After charging your battery, allow it to sit for two to three hours. Then, ride your LEV on level ground for three minutes. Allow it to sit for five minutes before measuring the voltage. Use the following table, determine the battery's state-of-charge.
approx. state of charge
SLA battery voltage
Hawker battery voltage
100%
12.66 volts
12.84 volts
75%
12.45 volts
12.48 volts
50%
12.24 volts
12.21 volts
25%
12.06 volts
11.85 volts
0%
11.89 volts
11.58 volts
Note: If the temperature of the battery is below 70 F, then add .012 volts (12 millivolts) per degree below 70 F.
A battery may have an internal hidden break. Monitor the voltage while pressing on various spots - especially around the terminals. A drop in voltage indicates a hidden break.

Controller Problems


Controllers are electronic devices that stand between the throttle (what you want the motor to do) and the motor. Most controllers are programmed to limit acceleration and top speed. Oftentimes, when something burns out in the controller, there's an unmistakable bad smell of burned electronics. When the burn first occurs, you'll likely also see smoke pouring out.

All electric motor powered vehicles have built in devices to protect them from damage caused by excessive loads or heat. These "excessive loads" and/or heat can be caused by high ambient temperature, heavy riders, hills, low tire pressure, lengthy high speed operation, or a combination of these factors. Generally, the protection devices are in the form of circuit breakers, fuses, current limiting circuitry, and thermal breakers. Their job is to protect the active electrical components from damage. These devices generally stop or retard the performance of your LEV. For example, if the controller detects a low voltage condition, it may stop the motor; going slowly and lightly on the throttle may allow you to limp along for another mile. In the case of overheating, you may have to wait 30 minutes before the controller allows you to go again.

Motor Irregularities


Neither brushed or brushless motors are designed with user servicing in mind. The bearings are sealed, and brush replacement is often a difficult process. The nominal service life of these motors is so great that service is essentially unnecessary. Even so, motors do fail.
If you open your motor for a look, check for these tell-tale signs of problems:
  • Brushes: pitted, burned, chipped, worn
  • Springs: discolored, dissimilar pressure
  • Armature: overheated (i.e. discolored) windings, loose laminations
  • Commutator: brush debris between segments, wear, erosion/wear, oxidation
  • Bearings: dry, loose, tight
  • Magnets: loose, scored by contact with armature
You can clean the commutator - gently - with emery paper. Carefully remove the debris from between the segments with a toothpick. If you replace the brushes, be certain they are exactly the same as the originals. Same with the springs, although sometimes it's advisable to use slightly stronger ones. You MAY be able to lube the bearings, but replacing them is probably best if they're the sealed type.
A good source for small motor brushes is an automotive electric shop that actually rebuilds alternators/generators. Another possibility would be W.W.Grainger or other industrial supplier that specialize in electric motors.

Throttle Problems


Diagnosing throttle problems:
Symptom: Either the throttle sometimes works, or it doesn't work at all AND the motor/controller smells OK.

Throttles come in three types: simple ON/OFF, potentiometer, and Hall Effect. With the simple two-wire ON/OFF throttle switches (used on Zappy, Tracker, Tomb Raider, Eboarder, etc.), start by unpluging the throttle from the the controller. Then, using a multimeter, measure the resistance through the throttle. It should be way high until you activate the throttle when the resistance will drop to near zero ohms. It it doesn't drop, the throttle switch isn't making connection. If you can't repair it, replace it.
With the potentiometer type of throttle (used on Currie, GT, Schwinn, and Mongoose scooters with finned motors, Currie bicycles, PowerCats Tiger scooters, Lashout scooters and bicycles, etc.), start by unpluging the throttle from the the controller. Then, using a multimeter, measure the resistance (Ohms) between 'common' and 'low => high'. The resistance should be below 100 ohms. As the throttle is activated, the resistance will rise to about 5,000 ohms. If initial resistance is 400 ohms, the motor/controller will think something is wrong and won't respond. Also, measure the resistance (Ohms) between 'common' and 'high => low'. The resistance should be about 5,000 ohms; as the throttle is activated, the resistance will fall to below 100 ohms.

Another test for the potentiometer type of throttle is to test the connection to the motor/controller. After unplugging the throttle wire from the motor/controller, turn on the power to the motor/controller. Then, use a paper clip to jumper between the two outer pins of the motor/controller's throttle connection (red and brown in the drawing). Doing so makes the motor run and continue to run until the jumper is removed. WARNING: make sure the drive wheel is off the ground and the vehicle is secure.

With the Hall Effect type of throttle (used on Currie, GT, Schwinn, and Mongoose scooters with brushed motors, most Chinese-made electric scooters, bicycles, pocket bikes, mini choppers and go karts, etc.), start by probing the throttle wires while still connected to the controller. This may require that you insert sewing pins or needles through the insulation of the throttle wires. Then, using a multimeter, measure the voltage on the three pin leads from the controller. Normally, the red wire carries 5 volts from the motor/controller to the throttle for the Hall Effect power source. The white or green wire is the ground wire. The yellow wire returns the Hall Effect voltage to the motor/controller; it ranges from 1.0V (for OFF) to 4.2V (for top speed).

Here's how the throttle voltage and Currie's brushless motor/controller work together for many throttles:

There are 3 wires that go to the throttle, let's call them SOURCE (black), SENSE (red), and GROUND (brown/common). With ground as reference: sense is at a constant +5V, SENSE controlls motor speed. Impedance from SENSE to GROUND is about 5Kohm, SENSE positive, power on. When SENSE rises above 110mV, the motor control circuit energizes. Below 180mV the motor doesn't turn but it becomes resistant to turning backwards. Above 180mV the motor starts turning. No matter how slowly SENSE is raised the motor starts abruptly with a slight jerk. Motor speed rises in proportion to the voltage on SENSE until it reaches 3.6V at which point the motor abruply jumps from medium to full speed.'

These wire colors and behavior varies. For example, one Hall Effect throttle has a red wire (+5v), green wire (+4.2V) and yellow wire (ground) while a second throttle has red (+5V), green (+4.2V) and black wires (ground).


Battery Charger


A 12-volt smart charger will charge the batteries up to about 14.4 to 15 volts before dropping into the 13.8 volt maintenance phase. To find out if this is happening, you need to monitor the charge voltage throughout the entire charge cycle.

The Soneil 24-volt chargers top at 28.8V - and cycle back on if voltage drops below 27.6V. Output voltage of most 24-volt chargers ranges from 27-28 volts, but always below 30.5 volts.

A 36-volt charger should finish the charge at 44.4V, then drop to 41.4 for maintenance.
The Deltrans is a constant current charger like the Soneil. However, it works a little differently in that it has 3 modes of charge:
  • constant current "BULK" charge (red LED)
  • slower topping off charge as the voltage approaches the peak of 14.9volts (red and green blinking LED)
  • stand-by charge of 13.5volts (green LED).
If the charger stops working, open it and re-tighten all connectors. Sometimes this will fix the problem.

Smart chargers switch their voltage down when fully charged to comply with battery manufacturers' stated "maintenance" voltage of about 13.8V. (27.6V for the pair). When the charging current falls to 125-150ma, the battery is fully charged. (for all practical purposes). Unfortunately, the some "stupid" chargers (generally with 1-amp capacity) don't drop voltage and keep charging at the 28.7V level! A "smart" charger will, at this point, drop to 27.6 volts. If you hear a sizzling sound, that's due to overcharging at the bulk charge voltage (28.7V). Over time, this will reduce useful battery life expectancy. If you have a dumb charger, unplug it when the green LED lights up.

3 LED smart chargers (such as the ZAP and EV-Warrior chargers):
If the yellow LED is on, the charger is properly connected to the batteries.
If the red and yellow are both on, that means it is charging.
If the charger never gets to the alternating yellow and green (charged/float) stage, then explanations exist:

1) One of the battery cells shorted within the battery and the battery won't ever charge to full voltage;

2) The "pot" needs to be adjusted to the proper output voltage. To make the adjustment yourself, first unplug the charger and then unscrew and remove the casing (back side). The pot is obvious, it's a small plastic white dial with a small slot. Insert a small precision (or any small slotted) screwdriver and turn it clockwise one or two degrees. 

Then close up the charger and plug it back into the battery pack and wall socket. Give it half an hour to charge to full capacity. If the scooter doesn't go to the alternating green/yellow stage, then repeat until it does. Important: do it in small stages (small turns of the pot each time, one or two degrees), even if it means opening and closing the charger a few times; that's better than having it set too high. When it does reach the charged stage, check to ensure it's at the proper finishing voltage. After it's charged, wait half hour or so and check the voltage of the batteries by inserting meter leads into charging port, it should read between 26.6 and 27 volts (for a 24-volt charger).

Wires, switches, fuses, etc.


If the fuse blows on a Currie scooters or Electro Drive bicycle systems, follow these diagnostics steps:

Is your battery box blowing fuses when connected to nothing?
  • IF Yes.... battery box bad.
  • IF No......Connect box to motor/throttle. Then turn battery box on.
Did fuse blow?
  • If no... then When does fuse blow?
  • If yes..... Disconnect Battery box and hookup alternate 24 volt source with fuse.
Does Fuse blow with alternative 24v source?
  • If yes.... motor/conroller bad.
  • If no.... check original battery wiring.
Blown fuses are an indication of something seriously wrong. Simply replacing the fuse doesn't prevent further failures. However, you can expect to blow one or more fuses performing diagnostic tests such as the one above. The 40A fuses used in Currie products are difficult to find at auto parts stores. Instead, try your local car audio store.

Check electric connections - especially at the battery terminals - for corrosion. If corroded, clean the connections and apply No-ox, Ox-guard, etc. It's a gray-colored conductive goop for copper and aluminum contacts. It's like vaseline mixed with graphite and is used commercially for electrical contacts to guard against corrosion. Some folks just use plain old wheel bearing grease.

Electric Bike Technical Guide

FAQ

What is VOLTAGE and which Voltage is best?

Voltage can be thought of as the pressure or strength of electric power. All things being equal (see AMPS below), the higher the voltage the better, because high voltages pass more efficiently through wires and motors. Very high voltages (100+ volts) can give you a nasty shock because they also travel through people rather well, but the sort of voltages found on electric bikes (12 – 36 volts) are quite safe. As a rule, a 12 volt system is fine for low-powered motors, but more powerful machines work better with 24 or 36 volts. Electric mopeds and motorcycles tend to use higher voltage – typically 48 or 60 volts.

What are AMPS?

Amps can be thought of as the volume or quantity of electric power. To aid this analogy, the flow of amps is called the current, as in the flow of a river. Unlike a river, though, the speed of the current is fixed – only the volume varies.
The maximum flow of amps in a bike drive system can vary from 10 to 60 or more. A current of 60 amps requires thick wiring and quite substantial switchgear.

What are WATTS?

Once we know the voltage (or pressure) and current (or volume), we can calculate the power, or wattage by multiplying the two figures together. The number of watts in a system is the most important figure of all, because it defines the power output. A few examples of electric bikes:
The Zap motor draws 20 Amps x 12 Volts = 240 Watts
The Giant Twist Lite draws 15 Amps x 24 Volts = 360 Watts
The Powabyke draws 20 Amps x 36 Volts = 720 Watts
The Curry Drive draws 40 Amps x 24 Volts = 960 Watts
Despite having a fairly low voltage, the Curry is the most powerful motor, followed by the Powabyke and the Twist, with the Zap coming in last. It’s impossible to calculate the power without knowing both the number of amps and volts. Large machines, like cars, trains and trucks have their power measured in the same way – usually as kilowatts, or units of 1,000 watts. The old-fashioned ‘horsepower’ unit is the equivalent of about 750 watts.

How many watts do I need?

As a general rule, a cyclist can produce several hundred watts briefly, and one hundred watts for a reasonable length of time. To be really useful, a motor needs to produce another 100 Watts on a continuous basis, with peak power of at least 400 watts. Just to confuse things, our measurements are of power consumption – losses in the motor and drive system mean that the power output to the wheel can be much lower.
If you expect the motor to do most of the work, especially in a hilly area, you’ll want a peak consumption of 600 watts or more. On the other hand, if you prefer gentle assistance, a peak of 200 watts may be enough. For a moped, power will be measured in thousands of watts (kilowatts or kW) rather than watts. A continuous rating of one kilowatt will just about keep up with city traffic, but two or three are more useful, and motorcycles will obviously need a lot more to keep up with traffic out of town.

How big a battery do I need?

The capacity of the battery is usually measured as the amount of current it can supply over time (defined as amp/hours). However, this is useless on its own, because you’ll need to know the voltage too. By multiplying the two figures together, we get watt/hours – a measure of the energy content of the battery. Unfortunately, it isn’t that simple… but you didn’t think it would be, did you? In practise, you’re unlikely to get results that match the stated capacity of a battery, because battery capacity varies according to the temperature, battery condition, and the rate that current is taken from it.
Lead/acid batteries are tested at the ’20-Hour’ rate. This is the number of amps that can be continuously drawn from the battery over a period of 20 hours. However, an electric bike will usually exhaust its battery in an hour or two, and at this higher load, the battery will be much less efficient. So the figures for lead/acid batteries tend to look optimistic.
On the other hand, Nickel-Cadmium (NiCd) batteries are rated at a 1-Hour discharge rate, so although the stated capacity of a NiCd battery might only be half that of a lead/acid battery, performance on an electric bike will be much the same. Nickel-Metal Hydride batteries (NiMH) are measured at the 5-Hour rate, so their performance tends to be somewhere between the two.
The capacities of typical bike batteries vary from Powabyke’s 504 watt/hour giant (36 volts x 14 amp/hours) to the tiny 84 watt/hour pack on the early SRAM Sparc kit.
It’s best to choose a package that will provide twice your normal daily mileage. It’s difficult to guess the mileage from the watt/hour capacity, because actual performance depends on the bike and motor efficiency, battery type, road conditions, and your weight and level of fitness.

How can I measure the efficiency of an electric bike?

We measure overall efficiency by dividing the watt/hours used by the battery charger by the mileage achieved, giving a figure of watt/hours per mile. This varies according to the terrain, the weight and riding style of the rider and the type of battery and charger, but our figures are measured in exactly the same way for each test, so they should be comparable, bike against bike. The best we’ve seen is 8 watt/hours per mile, and the worst is 32… Typically, an electric bike will consume 10 – 20 watt/hours per mile. So a big battery like the Powabyke’s will give a range of between 15 miles (doing all the work in quite hilly terrain) and 50 miles (a joint effort in flat terrain). This is fine for most uses, although it’s a big, heavy battery. As a general rule, medium-sized NiMH batteries on lightweight bikes give the best results: the Giant Twist runs for more than 20 miles on a 156Wh battery, and the faster Ezee Sprint more than 25 miles on a 324Wh battery. Small units, such as the Panasonic WiLL, give a maximum range of 5 – 10 miles.

Do electric bikes recharge when you coast downhill?

With the exception of the Canadian BionX, the answer is generally NO. Taking into account wind-resistance, road friction and so on, there’s surprisingly little energy left over for recharging the battery, even before generator and battery losses are taken into account. In most systems the motor coasts when you ride downhill, but those that don’t (mainly electric scooters) are capable of putting back only 15% of the power absorbed climbing the hill. Regenerative systems do have their advantages though – mainly in reducing brake wear and over-heating.

Which battery type is best?

LLead-acid batteries are cheap and easily recycled, but they are sensitive to maltreatment and have a limited life. Weight for weight, nickel-cadmium (NiCd) gives more capacity, but it’s expensive and the cadmium is a nasty pollutant and difficult to recycle when the battery fails. The life is greater, which tends to compensate, but disposal problems mean that nickel-cadmium has been phased out. NiMh is theoretically more efficient still, but these batteries are more expensive, and because the capacity is measured at the more generous 5-Hour rate, the advantage is not what it appears to be. Our experience is that NiMH offers little, if any, improvement in range over NiCd. They are, however, easier and safer to dispose of when they eventually fail, and the good ones will last for a considerable time.
But NiMH is now rare, because 95% of modern electric bikes come with Lithium-ion (Li-ion) batteries. These are more weight-efficient than the other types, and are supposed to have a longer life, but can do some odd things. Charging and discharging must be carefully controlled to prevent the cells going into terminal meltdown, so either the charger, the batteery or both will bepacked with electronics. Fires are now rare(!), but initial hopes that costs would tumble proved unfounded, and these batteries are currently very expensive. Cheaper ones abound, but their life can be very limited. Despite these problems, the Li-ion has become the default battery. Lithium-ion Polymer (usually called Li-pol) doesn’t really offer any performance advantage in terms of weight or range of Li-ion, but it’s safer and can be moulded into interesting shapes. No-one really knows what the life of the Li-ion battery will be, but early signs are not good.

Which charger is best?

Swings and roundabouts here. Batteries do not take kindly to fast charging, although NiCd and NiMH are more tolerant than lead-acid, which can start fast, but prefers a long tapering charge thereafter. A fast (sub four hour) charger makes a great difference to the flexibility of an electric machine. You can, for instance, travel for the full range in the morning, recharge while visiting a friend, and run home in the afternoon. No lead-acid charger can do this, although the best NiCd or NiMH chargers will. Newer Li-ion batteries with the control circuitry on board usually have a very simple charger, but the charge rate with this type will be quite slow for safety reasons. An advantage is that most 36-volt designs now come with a standard 3-pin plug, so the chargers are interchangeable. For basic commuting, an overnight charger is safest and kindest to the battery, but if you expect to push a high daily mileage, you’ll need something faster.

Should I choose a brushless motor?

Broadly speaking, there are three types of electric motor -
Direct Current motors – simple but comparatively heavy and slightly less efficient, and
Brushless DC (BLDC) motors – smaller, lighter and more efficient over a broader speed range, but with complicated wiring
Sensorless, brushless DC (Sensorless BLDC) motors – even smaller, lighter and more efficient, with simpler wiring, but slightly tricky to start
Direct Current motors have brushes to transfer power into the rotating bit. They are simple and reasonably reliable, but now very rare, fitted to abut 5% of bikes. The vast majority (around 80%) of electric bikes now use brushless DC motors. These are a bit more efficient, because they use electronics and sensors in the motor to do the bit the mechanical brushes do, but the sensors are linked to the control box by tiny wires, so they’re very vulnerable to mechanical damage. A more recent development is the brushless, sensorless DC motor, fitted to about 15% of bikes, but the number is gradually increasing. This uses clever electronics to eliminate both the brushes and the sensors, so everything is simpler except the electronics, which are fiendish. Sensorless BLDC will take over from BLDC, but don’t rule out Direct Curent brushed motors! They may have mechanical brushes, but they’re mercifully short of complex electronics.

What should I look for in an electric bike?

We’ve put together an electric bike specification wish-list below. At the present time, there are no machines that win in every category, but the closer yours gets the better. If the salesman is unable to provide all the answers, or starts blustering or attempting to blind you with science, we’d recommend looking elsewhere. A good shop should be able to provide most of the figures in a straightforward and honest manner, but some are quite incompentent:
Weight: Less than 30kg (66lb)
Price: Obviously as little as possible, but realistically, expect to pay $1,200+
Maximum assisted speed: Not less than 15mph (legal maximum)
Peak power: More than 300 watts
Power consumption: Less than 10 watt/hours per mile
Range**: More than 25-30 miles
Battery type: NiMH or Li-ion (nickel-metal hydride or lithium-ion)
Replacement battery price: As little as possible, but realistically, you’ll have to pay $300-$400 for a decent one. Whatever the price, INSIST on a two year guarantee
** You’ll need to verify this for yourself – manufacturers figures are universally dubious
A few other pointers: If you are expecting to tackle very steep hills (in excess of 17%, or 1 in 6), we’d recommend a Crank Drive motor. This type puts power through the rear gear system and can be fine-tuned to suit almost any environment. It’s the best system if you can afford it. The more common Hub Motor effectively has only one gear, and although some are very powerful, it will prove less efficient in a really hilly area. For most other purposes a hub motor is fine, but avoid Friction Drive unless you intend to make light use of the bike. The roller and/or the tyre tend to wear out in a few hundred miles.