Bicycle on LEl_FENG Blog

About Adding a Voltmeter, a 24V High-Speed Fan, and a Thermometer to My Bicycle

Thu, 19 Jun 2025 06:51:23 +0700

TL;DR / Geek Summary:

Hardware Upgrade: Integrated active cooling and monitoring cluster for the e-bike.

Thermal Solution: Added a 24V high-speed “violence” fan to prevent controller burnout.

Telemetry: Real-time voltmeter and thermometer (with direct probe placement) for critical subsystem monitoring.

# About Adding a Voltmeter, a 24V High-Speed Fan, and a Thermometer to My Bicycle

Because frying the controller on my bicycle has basically become a daily routine, I decided to add a voltmeter, a 24V high-speed fan, and a thermometer. The high-speed fan is for heat dissipation, the thermometer is to monitor the temperature, and the voltmeter is to monitor the battery’s voltage.

# Unboxing

A bunch of tools and their corresponding accessories.

# Fan and Controller

These two need to be put together to be effective. It used to rely entirely on passive cooling, but now that it has active cooling, it should extend the lifespan of the controller.

# Thermometer and Its Probe

Just place the probe directly on top of the controller, and connect the other end to the display screen.

# Connecting the Battery and the Voltmeter Together

This way, it can successfully display the voltage.

# The Final Assembled Result

It works pretty well!

Riding My Modified E-Bike to Enjoy the Scenery Along the Way

Wed, 18 Jun 2025 11:41:44 +0700

TL;DR / Geek Summary:

Mission Report: Field testing the DIY e-bike across grassland and riverside terrains.

Performance Metrics: Achieved ~75km range (3 hours @ 25km/h) on flat ground.

Log: High-torque off-roading success; documentation captured via smartphone (no action cam budget yet).

# Riding My Modified E-Bike to Enjoy the Scenery Along the Way

The modified e-bike can manage to run for about 3 hours on flat ground at a speed of 25 km/h, which is equivalent to a 75-kilometer range. While riding, I can enjoy the scenery along the way. I didn’t bring an action camera because my budget doesn’t support buying one, but taking photos with a phone doesn’t make much of a difference anyway, so I snapped a few, haha.

Grassland off-roading

And by the river

Uhh, I can’t push it too hard or it might break, doge

Converting a 26-Inch Vintage Bicycle into an E-Bike with a MY1016Z2 Motor and LiFePO4 Battery

Tue, 17 Jun 2025 22:11:23 +0700

TL;DR / Geek Summary:

Hardware Hack: 15-year-old vintage bicycle retrofitted with MY1016Z2 brushed motor.

Power Cell: Custom-built 24V 15Ah LiFePO4 battery pack with 40A BMS and active balancing.

Geek Factor: Prioritized brushed motor for the “mechanical engine sound” vibe; includes 24V-to-mobile charging.

This bicycle has been ridden for 15 years. I found that the bottom bracket, tires, brakes, and the center headset screws were getting quite old and produced strange squeaking noises when riding, so I decided to convert it into an electric bike.

On Taobao, there are both brushless and brushed motor versions available. However, the brushless motor version is very complicated—it has three wires, unlike the brushed one which only needs two to get the job done. Plus, brushless motors require an ESC (Electronic Speed Controller) and Hall sensors. Sellers usually sell them as whole kits, and they are not cheap. Moreover, brushless motors don’t have that “engine sound,” making the ride feel a bit dull. This brushed motor, being a gear reduction motor, produces a very loud mechanical gear sound, giving it the feel of riding a motorcycle.

I used this MY1016Z2 brushed DC motor I had on hand to modify the bike. Honestly, I’m not a total professional at this, but I figured out some parameters and wiring diagrams while tinkering with it and thought it would be fun to share. In mainland China, you can’t officially register a heavily modified bike like this and will face fines if caught on the road. If they allowed such modifications, the speed-limited standard national e-bikes wouldn’t sell at all. But such DIY modifications are generally fine abroad.

Because the voltage difference (cell imbalance) of LiFePO4 (Lithium Iron Phosphate) batteries can get quite large, an active balancer is necessary. Otherwise, after prolonged use, the cells will become highly unbalanced, and the battery won’t be able to charge properly.

Since the charging current can be quite high, reaching up to 10A, I soldered two connectors to combine the power interface and the charging interface together.

For motors like this, a 20A protection board (BMS) is useless even if the motor’s rated current is 13A; it will still easily trigger the overcurrent protection. So, I chose a 40A protection board. My battery has a capacity of 15Ah and a 2C discharge rate, which means the maximum continuous discharge current is 30A. The BMS rated at 40A is perfectly fine and won’t exceed the battery’s tolerance. Note that my battery pack can handle a peak discharge of 3C.

Here is the battery pack assembly process. Once finished, it was ready to use.

It can also step down the 24V power to charge a mobile phone.

My next article will be about taking this e-bike out for a ride to enjoy the scenery!