After the ignition system comes the charging system. Reinforcement measures include full-wave rectification, a high-capacity battery, and conversion to LED bulbs.

HONDA Trail CT110 Hunter Cub 1981 Semi-Restoration Vol.17

The CT125 Hunter Cub is now recognized by everyone as a best-selling model. Its ancestor is the CT110 Hunter Cub. By replacing it with an early CT110 CDI stator coil (a bolt-on conversion of the CDI coil & rotor to a battery-ignition engine), the ignition system finally became normal, and I was able to achieve excellent running performance. The next thing I thought about was strengthening the charging system.

Equipped with a well-regarded BS Battery gel-type SLA model

I chose a battery size that is also used in modern 12V mopeds. It is the largest battery size that can physically fit inside the CT110 frame. I chose the BS Battery SLA gel-specification BTR4A-5. Since it is a gel specification rather than an electrolyte one, it can be mounted on its side.

Equipped with a modern scooter "full-wave rectifier regulator"

For the full-wave rectifier regulator, I chose an Asian-made one purchased via online mail order (likely made in Taiwan or mainland China). I think I'll be lucky if it doesn't break, but it has a reputation for being surprisingly tough.

I installed the rectifier regulator in the space on the upper left side inside the side cover area. I plan to make a battery mount for the frame by making a paper pattern and then fabricating it from sheet metal. I will use a 1.5mm thick steel plate.

If you want to brighten your headlight, paying attention to "part condition" is important

Since I'm going to the trouble of converting to 12V, everyone would think about wanting to make the headlight brighter. I learned that the headlight of the MD90 postal bike has the same dimensions and can be used, so I bought one immediately.

The bulb for the MD90 was a more modern design than the domestic CT110 one. The reflector is a separate specification from the glass lens. The shine of a new reflector is completely different!! After all, shine is justice.

Achieving overwhelming "brightness" and "energy saving" with LED bulbs

The 12-volt LED bulb has a one-tab specification on the set flange. Compared to the MD90's one-tab specification, the genuine CT110 one has a three-tab specification common in older vehicles from the 70s and earlier. Since there are few old-type LED bulbs, I updated to the MD90-type one-tab specification at this timing.

The bulb socket released by Daytona was a perfect match!! Bought it immediately

I purchased the MD90 reflector, lens gasket, and socket as genuine Honda parts. When I was looking for a coupler compatible with the bulb socket, I found that Daytona had released a coupler + terminal set!!

I used a clamp tester to measure power consumption in DC (direct current) ampere mode. The power consumption is clearly different between the incandescent bulb headlight and the LED bulb headlight!! The incandescent bulb consumes 2.24 amperes.

On the other hand, the LED bulb is not only bright but also consumes less than half the power of an incandescent bulb at 0.92 amperes!! Power saving through LED bulb conversion can be visually measured if you have a clamp tester that can measure DC amperes.

Honestly, there are preferences for a bright, white light (the impression varies from rider to rider), but visibility is overwhelmingly improved!! Compared to the 6V era, which was like a paper lantern, it's brighter and safer for touring.

Modified to allow installation of a "small lamp" on the late-model reflector

The MD90 genuine reflector I purchased is from a model year that adopts the always-on headlight of the final carburetor specification. Therefore, there is no position lamp. I used a single-character drill to additionally machine a hole in the reflector.

I machined a hole in the same position as the previous reflector so that a position lamp could be set. By converting this position bulb to an LED, it is quite bright and has good visibility even when using the small lamp!!

Conversion to an LED turn signal relay makes the use of "LED bulbs" possible!!

For 12V LED turn signal bulbs, I recommend the ones made by Daytona. Unlike products that simply have LED chips facing forward, LED bulbs equipped with partitions have a wide, bright area due to the reflector effect.

When replacing turn signal bulbs with LED specifications, you must simultaneously install a dedicated turn signal relay that supports power saving. With the turn signal relay for incandescent bulbs, you cannot get the correct flashing speed.

I installed a turn signal harness (diode rectification) that is sold as a countermeasure part for turn signal indicator lamp malfunctions. After installation, it stopped malfunctioning. Now it's perfectly safe!!

A characteristic of LED bulbs is that they light up even with minimal power. Due to this LED bulb conversion, the turn signal indicator lamp malfunctioned. So, I purchased a countermeasure part from Daytona.

The CT110 was a ragged vehicle that had been ridden hard, but it is somehow being finished beautifully. Since the frame has not been repainted (only touched up), the finish does not look like a full restoration vehicle at all.

A domestic model CT110 (originally a battery point ignition specification vehicle) updated to a CDI ignition system using genuine parts. Since the ignition system problem that was in poor condition was solved, I decided to modify it to "12-volt control," which is bright and safe even for night riding. Depending on the output status of the stator coil, there are many examples where even a genuine generator managed at 6 volts has sufficient power generation capacity depending on the model, and it can be converted to 12 volts by managing and controlling it with a regulator.

Conversely, there are models that cannot be easily converted to 12 volts due to marginal output. For example, even with the original Super Cub Honda C100, there are differences in actual power generation output between generators made by Denso, Mitsuba, Kokusan Denki, and Mitsubishi. While there are types that can be stably converted to 12 volts by installing a 12-volt rectifier regulator, there are also those made by manufacturers that cannot be easily converted to 12 volts due to insufficient capacity. It is not a question of which is better, but if you are going to perform a modern modification = 12-volt conversion, stable output is definitely better, and it is overwhelmingly safer.

If you ask how it is for this CT110, even if I replaced it with a new rotor & stator coil, I could never get a good output situation. I installed a "full-wave rectifier regulator" that can charge efficiently instead of installing a normal 12-volt specification rectifier regulator, installed a 12-volt battery, and checked the charging status. As a result, if I left it with incandescent bulb specifications, symptoms of insufficient charging occurred during normal use.

Specifically, after confirming 12.8 volts at the terminal voltage when the battery was fully charged, I took it for a test run with incandescent bulbs. I drove with the headlight on, and switched to the position lamp at red lights. I returned to the garage after driving 30km like that. When I measured the battery terminal voltage, it was 11.8 volts, which was clearly insufficient charging.

Next, I converted the bulbs to LED. After confirming the battery terminal voltage was also 12.8 volts, I departed for a test run on the same route and with a similar driving style. When I measured the battery terminal voltage after returning to the garage, the battery terminal voltage was 12.4 volts under the same test conditions. After that, when I drove the same way without turning on the headlight, it marked over 13 volts. From this result, it can be judged that the power-saving effect of LED bulbs is significant.

If the power generation capacity had been sufficient, it would have been in a stable charging state even with incandescent bulb specifications. In fact, there are models where you can convert a moped to 12 volts and it is completely fine with incandescent bulbs. The Super Cub 70 Kamome K1 that I own is a concrete example of that.

Since I didn't get good results with incandescent bulbs, I replaced all the bulbs on the CT110, such as the headlight, tail lamp W-bulb, meter illumination, indicator lamp, and turn signal bulbs, with LED specifications. I've been driving for a while after such modifications, and it seems to be in good condition without any trouble at all. Even so, I tell the owner, "Please connect a 12-volt charger occasionally." By the way, including the ignition system, the current electrical system is extremely stable. It continues to run without any problems at all.