We've lost count of how many times a customer has walked into our Gujranwala workshop with a motorbike that was supposed to already be an EV. Someone else converted it. It cost them PKR 40,000. Now it won't run more than 20km, the controller gets scorching hot, and there's a faint burnt-plastic smell after every ride. We rebuild it properly and it costs them another PKR 50,000. Total spend: PKR 90,000. A proper build from scratch would have been PKR 65,000.
This is the real cost of a bad conversion. Not just money — time, frustration, and in some cases, a genuine fire risk. After 1,200+ builds since 2018 and dozens of "rescue" jobs on other workshops' work, here are the ten mistakes we see over and over.
We've fixed dozens of botched EV conversions from other workshops across Punjab and Sindh. Every single one of the mistakes below was present in at least one rebuild we've done. Some bikes had six of the ten simultaneously. Read this before you convert — or before you trust someone else to convert for you.
Hub motors are available in Lahore's Hall Road and on Daraz for PKR 8,000–12,000. They look identical to quality motors. They are not. The difference is the copper winding inside — cheaper motors use thinner wire wound fewer times, which increases resistance, reduces efficiency, and creates heat under load.
Understanding the numbers is critical: every motor has three wattage figures. Peak wattage is what the motor can briefly handle without immediately dying — it's the number on the label. Rated wattage is what it can sustain for extended riding. Continuous wattage is the real thermal limit for hour-long use. A motor labeled "1000W" is typically 250-350W continuous. A quality 500W rated motor handles Pakistani roads. A cheap "1000W" motor's continuous real-world rating might be 180W — it overheats on GT Road within 15 minutes and starts dropping performance to protect itself, or simply burns out.
The fix: buy from verified suppliers or through a workshop that tests motors before installation. The price difference between a quality 500W hub motor and a cheap "1000W" motor is PKR 5,000-8,000. The price difference when the cheap motor burns out and takes the phase wires with it is PKR 15,000-25,000 in repair work.
The Battery Management System is the electronic brain that prevents your lithium pack from killing itself. It monitors each cell individually, cuts off charge when cells reach their maximum voltage, cuts off discharge when they reach minimum voltage, and shuts down during overcurrent or overtemperature events.
In the Pakistani market, two things happen with BMS: either it's skipped entirely to save cost (PKR 1,500-4,000 savings), or a counterfeit unit is used that looks correct but has no real protection circuits. We've opened "48V 60A" BMS units that cost PKR 600 and found nothing but a tiny microcontroller with no MOSFETs — literally incapable of handling more than 5 amps regardless of the label.
A battery pack without a functioning BMS is a pack where one weak cell will be overdischarged while others are fine, killing it permanently. It's also a pack where a short circuit has no protection. We don't use the word "fire risk" casually — it's what actually happens when lithium cells fail uncontrolled.
This one is about basic math that people skip. A 60V 20Ah battery has a total energy capacity of 1,200 watt-hours (60 × 20 = 1,200Wh). Your converted CD70 at 60V draws roughly 20-25 amps at city riding speeds, meaning 1,200-1,500 watts. At that draw rate, your pack lasts 48-60 minutes of actual riding — call it 30-40km real-world in Lahore traffic. Someone buying a 60V 15Ah pack to "save money" gets 22-28km before the BMS cuts out. That's not a commuter vehicle. That's a liability.
The formula is straightforward: estimate your daily route in km, add 30% buffer, then work backwards to the pack size you need. For a 50km daily commute on a CG125-class bike, you need minimum 60V 25Ah. Don't undersize the fuel tank and then complain about range.
Electrical wire has a current rating. Exceed it and the wire heats up. Exceed it significantly and the insulation melts, conductors touch things they shouldn't, and fire follows. On a 60V system drawing 40 amps continuously, you need minimum 10AWG wire (approximately 5.2mm²) for the main battery-to-controller run. We've seen builds using 16AWG (1.3mm²) that's rated for 13 amps — the insulation was brown and brittle within two months of heavy use.
Pakistani electricians are skilled with house wiring but don't always know DC high-current sizing. The rules are different from AC wiring. Every connection point is a potential resistance source: use proper crimp connectors, not twist-and-tape, and keep wire runs as short as possible. Short runs equal lower resistance equal less heat.
Karachi, Lahore, Islamabad — Pakistan gets real monsoon rains in July and August. Water and DC electronics don't coexist. Controllers mounted under the seat with their connector ports facing down and exposed get water ingress. A controller that trips once from water damage often develops intermittent faults that are maddening to diagnose.
The fixes are not expensive: use IP65-rated connectors for all external connections, position the controller with port openings facing downward, use self-amalgamating tape or heat-shrink on any connection that isn't a proper sealed connector, and mount the battery pack in a position where road splash doesn't hit it directly. None of this adds significant cost — it's just discipline in the build process.
Square-wave (trapezoidal) controllers are cheaper but deliver power in a rougher, more abrupt pattern than sine-wave controllers. For a basic, robust hub motor this is acceptable. For a quality high-efficiency motor — especially one with a higher pole count for better torque at low speeds — square-wave control causes more heat in the motor windings and noticeably rougher power delivery. At low speeds, the bike lurches slightly with each commutation step instead of pulling smoothly.
The price difference between a quality square-wave and a quality sine-wave controller is PKR 2,000-4,000. On a PKR 60,000+ conversion, this is not the place to save money. Sine-wave controllers also tend to be quieter — the distinctive high-pitched whine from cheap EV conversions is often a square-wave controller artifact, not an inherent property of electric bikes.
A freshly converted bike has dozens of new connections, a new motor seating into its bearings, and a new controller that hasn't thermally cycled. The right approach: first ride is 10-15km, check all connection temperatures, listen for unusual sounds, check motor temperature. Second ride 20-30km. Only after 100km of short rides is it reasonable to start longer trips.
What actually happens: bike gets converted on Saturday, owner immediately takes it Lahore to Gujranwala on Sunday. A connection that would have been caught on a 15km break-in run fails at 50km with no support available. We've received distress WhatsApp messages at 11pm about exactly this situation more than once.
Marketing wattage on Pakistani market motors is fiction. A motor labeled "1000W" is almost never 1000W continuous. Peak wattage numbers can be gamed by running a motor at maximum current for five seconds before it overheats and calling that the rating. The number that matters is continuous wattage under sustained load — which for most "1000W" hub motors in our market is 250-400W.
Ask for the actual continuous current rating and the motor's rated operating temperature. A quality 500W motor from a verified supplier will outperform and outlast a cheap "1000W" motor by a factor of three or more. Don't buy motors based on the label number. Buy based on supplier reputation, verifiable specs, and thermal testing.
This one is non-negotiable. Every EV build needs a properly rated fuse — or better, an ANL fuse holder — between the battery positive terminal and the controller. If a phase wire shorts to ground (which can happen if wire insulation wears through against the frame), without a fuse the battery pack attempts to deliver thousands of amps into a dead short. The wire becomes a heating element. The heating element ignites insulation. The insulation ignites the battery pack if it's nearby. This is how EV fires start.
A proper ANL fuse holder with the correct rating for your system (typically 80-150A depending on build) costs PKR 500-1,500. There is no justification for skipping it. We don't deliver a build without one. If someone quotes you a conversion without mentioning fusing, that's a warning sign about every other decision they're making too.
The EV conversion market in Pakistan has exploded since 2020. There are now mechanics in every city who will convert your CD70 for PKR 25,000. Some of them are skilled. Most are not — they've watched YouTube videos, bought cheap parts from Hall Road, and are learning on your bike. When it fails three months later (and it will), they're unavailable, the warranty is verbal and meaningless, and you're paying another workshop to fix it.
What to look for in a conversion workshop: do they have builds older than one year that you can contact the owners of? Do they show you exactly which components they're using and explain why? Do they provide a written spec sheet after the build? Do they offer post-build support? A workshop doing this work seriously will answer yes to all four. The extra PKR 10,000-20,000 for a proper build is not a premium — it's the cost of not paying twice.
"The cheapest quote is almost never the cheapest outcome. We've fixed enough botched PKR 25,000 conversions that now cost their owners PKR 70,000 total to know this is true."
| Mistake | Immediate Cost Saved | Actual Total Cost | Risk Level |
|---|---|---|---|
| Cheap motor | PKR 5,000–8,000 | PKR 20,000+ repair | High |
| No / fake BMS | PKR 2,000–4,000 | Full pack loss + fire | Critical |
| Undersized battery | PKR 8,000–15,000 | Unusable range | Medium |
| Thin wiring | PKR 1,000–2,000 | Melt / fire risk | High |
| No waterproofing | PKR 500–1,500 | PKR 8,000+ controller | Medium |
| No fuse | PKR 500–1,500 | Pack fire | Critical |
| Wrong workshop | PKR 10,000–20,000 | Double the total spend | High |
Every mistake on this list was made on bikes we've fixed. None of them are theoretical. The patterns are so consistent that within five minutes of looking at a botched conversion, we can usually identify which ones the previous builder made without even starting the diagnostics. It's not rocket science — it's just doing the work properly with the right parts the first time.
1,200+ builds done properly. Every component verified. Every connection tested. Get a conversion quote from MZEV and don't pay twice.