case for DC-DC boost converter without fan

I remixed and modified a similar box with fan to be suitable for my usage. I used to charge my portable 36V e-bike battery in a public library and request a pretty quiet charger - the original charger with fan is too noisy. BTW I use an adaptor converter so that I can charge my battery using my dell laptop adaptor (65W). it has been tested great and I'm very satisfied with it.