Putting a 1" hole for a vent on a D2C bike?

[slaphappygamer]

So, right here, behind the chainring. The thin part under the battery. This is where the controller is currently installed. I'm thinking of cutting a 1" hole for a round vent and maybe one on the other side as well. Would introducing these 1" holes on either side create structural issues to the frame? There is already an opening under the bottom bracket for air to pass upwards and the vents, I believe, would let that air flow up and out of that cavity.

The vent would look something like this.

 

[99t4]

What are you trying to achieve?

 

[slaphappygamer]

I’ve been monitoring the temp in that cavity, between the battery and the bottom bracket. I have a temp sensor glued to the outer part of the controller, just behind the FETs. It never gets above 50c. I’m sure the inside of the controller is hotter. I’m just thinking of how to get more airflow in that area, as opposed to externally mounting the controller. The controller is 48v 25a (max).

 

[amberwolf]

If the outside of the controller in an enclosed space with little or no airflow reaches and maintains a certain temperature, then the inside of it will be the same temperature.

There will be momentary increases at the FETs, but if the case at the FET location does not increase in temperature momentarily after high-current motor demand, then the system is not peaking to much above what you see outside.

The best thing you can do to cool the controller other than external mounting would be to secure it to the frame / housing itself, at the area of the casing that the FETs are mounted to, so that it conducts the heat directly to the frame, which then already has aircooling and a lot of surface area. This is best done to an unpainted area of the inside of that housing, that's flat enough to mate fully with the controller's flat casing area.

 

[leffex]

Don't make something simple more complex, dude.

We get the point in one sense(higher reliability maybe) but water is also an enemy that want to get in and does so by temperature change from day to night just by moisture in the air.

Yes, water gets inside where no one has been before.

After warranty period is over its free play to do mods on your bike.

 

[slaphappygamer]

If the outside of the controller in an enclosed space with little or no airflow reaches and maintains a certain temperature, then the inside of it will be the same temperature.

Ok. Good to know. Sounds like Im in good shape then. Usually the temp is 35-45c and nears 50c but never exceeds that.

I started working on my bike after only 8 months. To gain better hill climbing and better lighting. I’ve had it for a few years now and has been working well. I worked all the connectors on the new controller so I could swap the original controller and display if there was any issue with the new controller. I have almost 2000 miles on the new set up.

 

[leffex]

Ok. Good to know. Sounds like Im in good shape then. Usually the temp is 35-45c and nears 50c but never exceeds that.

I started working on my bike after only 8 months. To gain better hill climbing and better lighting. I’ve had it for a few years now and has been working well. I worked all the connectors on the new controller so I could swap the original controller and display if there was any issue with the new controller. I have almost 2000 miles on the new set up.

Cool

I would do kind of the same like you.

So is the original controller in the backpack? for fast switch heheh

It seems to be a reliable system that you build from what you are saying.

 

[slaphappygamer]

Haha. No. No backpack The original controller was in my bench while I was getting the 25A KT controller wired up and matched the JST plugs. i had to repin the throttle and change it from male to female. I re did the connection at the controller, so the original inputs matched and I can swap the original controller in if I need to troubleshoot anything. The original controller and display work fine and are now in a box in the garage.

I went with the 25A version because the physical size was almost the same as the original 22A Lishui controller. That controller was limited to 18 amps. I’m not looking to mob around with my crew and doing wheelies on the freeway. I just needed a bit more torque and the KT controller has many other options to set. It’s been very reliable. I’ve only had one fault, with the throttle. It completely cut out on me. After isolating the trouble, it turned out to be a loose connection at the JST plug I made. I cut off the faulty pin and installed a new one. When I first crimped the JST pin, I didn’t crimp it right and that’s why it became loose. Now it’s in there good and working fine.