Quiet 36V charger?

[drewdiller]

I have a 3.5A charger from E-bikekit, it works fine.

The problem is that the fan emits an annoying whine (it is, after all, a small diameter fan). It annoys the crap out of my wife.

Move the bike so that the wife can't hear it, you suggest. My problems with that very reasonable idea: (1) My garage was broken into and I don't trust things out there until I beef up security, but more importantly, (2) I ride during the winter, which means I have to charge in a warm environment (garage is unheated).

Anyone know where I can find a reasonably quick charger for a 36V battery that is whisper quiet?

If I need to, I'll disassemble the charger and replace the fan with the most quiet computer enthusiast fan of the same size that I can find...

 

[Drunkskunk]

I've found, when dealing with women, if she's complaining about the sound of a little fan on your charger, then it has absolutly nothing to do with the fan. Women don't complain about trivial things unless they are really anoyed with something else, and trying to provoke you into noticing.

Or the alternitive is its a dominance play on her part. She's trying to assert her dominance over you by rejecting something you enjoy.

Either way, fixing the problem has nothing to do with the charger.

 

[drewdiller]

Normally I'd agree with you -- she was resistant to e-bikes initially and my build project until she finally rode the damn thing herself and came back with the "EV grin" =)

 

[dogman dan]

Let her work in construction for oh, ten years, and then she'll say, " what noise"

But seriously this time, try taking it apart and putting a spot of oil on the hub of the motor if it's accesible. If not, if the charger is plastic drilling lots of large vent holes in the chargers case may give it plenty of cooling by convection. Then you could just unplug the noisy fan. And lastly, the fans are not that rare sized, so you might be able to get one the same size and just replace it, hoping the new one isn't just as noisy. Mabye you could have the charger in the garage and the battery inside somehow?

A high squealing noise can get pretty annoying. Even deaf as I am, I sure was glad when my neighbor replaced his squeaky air conditioner. Every time you went in the yard, squeak squeak squeak, 24-7.

 

[dnmun]

someone mentioned a special oil they found at radio shack or some similar place.

i just used 3in1 and it worked fine.

with the end of a sharp blade like an exacto knife, you have to get under the edge then lift up and remove the circular decal on the end of the fan, then the plastic disk underneath that, to expose the end of the shaft, apply just a few drops avoiding the contact cement that holds the decal in place so that you can pop it back together and have that contact cement still hold the decal on and keep the oil sealed inside. but stand it on end while you let it sit so the oil goes down the shaft and not out onto the decal.

ask your wife if you can use her sewing machine oil.

 

[John in CR]

Open it up and replace the fan with a whisper quiet one for PC's...Simple and cheap. 8) You should have her moaning and screaming and passing out afterward, so little noises can't bother her anyway....even cheaper and a lot more fun!

John

 

[drewdiller]

LOL

Awesome.

 

[02jze]

Stop charging the batts in the kitchen and she wont be able to hear it.. lol

 

[amberwolf]

Usually the whine is not from the bearings in the fan, but rather the eddy currents of air and interference from objects preventing smooth airflow thru the fan, like grillework and stuff.

If you can remove any grillwork around the fan to allow it maximum airflow with no interrruptions, it will help. If possible, just cut the entire circle out within the mounting bolt circle, just a bit larger than the actual fan inlet circle on the fan itself.

If there are wires in the path of the fan air close to the fan, move them and tie them out of the way, too.

Most of the air-cooled PCs and other items I have done these things to are at most 1/3 as noisy as they were before doing this, some are not even 1/10 as noisy, depending on how high the airflow was trying to be before doing it.


While you're in there, you can also check to see if the MOSFETs and other heatsinked items use that gray rubber stuff, and replace it with Kapton. Then if the heatsink bolts to the case, like my HighPowers do, carefully sand off all the overspray paint on the inside of the case, and then add just a little bit of thermal paste to that part of the case, so that when you bolt the heatsink back to the case it has a much better thermal conductivity. Removing any labels (and perhaps paint) that are right there at that part of the case will also help with radiating the heat away.

If you do those things, it might even be possible to slow down the fan's speed a little bit, without compromising the ability of the charger to stay cool and safe. That will also reduce the fan noise (sometimes drastically).

 

[drewdiller]

Good idea, there is a significant amount of grill work.

Wondering if I could cut a hole for the fan in a different location, so I could mount a fan with a diameter larger than the measly 45mm it has currently.

 

[dnmun]

the noise will stop if you just oil it. i am not sure why the chinese don't put oil on the shaft when they make them. it is a brass bushing which needs oil.

 

[amberwolf]

Some of them do; the fan in one of the the HighPower NiMH chargers I have had come with oil (there were marks indicating it started out with more than it had when I peeled back it's label to try to find the source of the chirping during checkout and troubleshooting--the chirping is unrelated, caused by debris under the fan core housing itself).

But you're right; I have fixed plenty of noisy or seized fans that obviously never had any oil at all.