Finally some sanity while charging !

Why do they jam those darn tiny little high pitched noisy F%##%ng fans in chargers these days? I could hear the darn thing from the street!

So after other attempts to shut the sucker up I came up with this






Fully sealed with hot glue, air tight and forces a good CFM of warm air out the vents of the charger. Ah finally silent charging. It was so bad I could still hear the thing hours after it was off. So sanity is hear.

This is my prototype for now, aim to come up with a lower profile setup.

I did try and have the fan hooked to the controllers auto fan circuit , but it didn't throw enough watts and could barely turn the fan.

could be worse
...thinking fans used in sealed equipment that spin so fast the tips of the fan blades break the speed of sound!
I can still hear those lil' screamers even though I stopped working around them 40 years ago.
(EEEEEEEEEEEEEEEEEEEeeeeeeeeEEEEEEEeeEEEE)

Jestronix said:

Why do they jam those darn tiny little high pitched noisy F%##%ng fans in chargers these days?

Click to expand...

Unfortunate consequence of the tiny ebike market. We aren't the intended consumer of these chargers. They are designed for recharging drones out in the field (hence 12V supply and compact size). Flyers want fast charging too, and high power levels means lots of waste heat, which means lots of air flow is needed, which means either a big (quiet) fan or a fast (loud) fan.

Nice hack though, I'm considering a UN-A9 charger so I'll keep this in mind.

Wow, love the thing! Now I'm thinking i should build my 18650 pack inside such a wind tunnel to keep it cool . Heat goes up, so one fan sucking air in at the bottom of the pack and one fan on the to top of the pack to poush the hot air put of the pack. That'd be crazy..

If the pack gets hot enough to need taht kind of cooling, it's either using the wrong kind of cells, or not enough of them.


Regarding the fans in chargers, I gotta say I love the Satiator and the Meanwell HLG series for the simple fact they are fanless and made to handle that.

I can't count the number of my electronic devices over the years that failed because their fans either stopped working suddenly, or got plugged up with dog hair and dust without me noticing, etc. I eventually had to start doing what you did with your charger; huge fans that just moved a lot of air slowly, as they didnt' fail nearly so easily or often, and were harder to plug up with debris.

Matador said:

Wow, love the thing! Now I'm thinking i should build my 18650 pack inside such a wind tunnel to keep it cool . Heat goes up, so one fan sucking air in at the bottom of the pack and one fan on the to top of the pack to poush the hot air put of the pack. That'd be crazy..

Click to expand...

I had the same thought, but in reality u shouldn't be pushing cells that hard! Then again tesla actively cools their cells, pushing too hard ? I'd say they do it for longevity, proabably reducing the total temp swings, or is it just for ludicrous mode ?

amberwolf said:

If the pack gets hot enough to need that kind of cooling, it's either using the wrong kind of cells, or not enough of them.

Click to expand...

You're right LOL... I don't plan to use my Sony VTC4 anything higher than 40°Celcius anyways :wink:
I'm currently (and slowly) building a 14S10P pack out of VTC4 for my 30 amp controller BBSHD so the battery will handle it with good very confortable margin (GOAL : Long lifetime of the battery). Just one VTC4 cell is rated : 2.1Ah, Max 30A/cell , BUT AT 100°C when reaching 0%SoC @ 30A, compared to 80°C @ 20A or 50-55°C @ 10A/cell...




It's just that I'm having lot of fun building an overspecd battery.... Fantisizing about cooling solution.... The wind tunnel (with double fans and venturi effect in the middle ) solution is just plain cool.... but it takes more space and I think It's a bit impractical...

For the cells, Il will parrallel cells with copper bussbars (1.7 mm thick, 9 mm wide) by soldering the 18650's original spot-welded tabs (0.15mm x 7 mm nickel-plated COPPER tabs... One tab leg = around 16-18 A ampacity ... here I'd have two tab legs per cell soldered to bussbar .... so it'd be good for more than the cell's max 30A rating.) directly to the bussbars. A bit like that :


View attachment 2

Yes, overkill, but the cell have such low DC-resistance/AC-impedance (see graphs)... I think they deserve good connections !



And as you can see on second graph... controlling Temperature (as with fans for example) can mean tweeking for the best compromise between Lowest possible internal resistance from high enough temps but not so high that it will cause cell damage/premature death from overheating.


For wire, il will use real copper 4AWG welding cable (not the CCA crap 4AWG you saw in this image... Copper Clad Aluminium is the biggest scam ever).



For andersons connectors, I will be using Anderson powerpole PP75 (max 120A continuous) with 6AWG silver plated connectors (they fit very snug on 4AWG cable).

One day, i will have to upgrade my BBSHD controller Maybe something like that... https://endless-sphere.com/forums/viewtopic.php?f=28&t=83450&start=150

BTW : Thanks to all the people who published these graphs on ES forum about then VTC4 cells (and all other cells)... They are not from me, I just reposted them. I think they are very usefull to predict how battery pack can behave in practice. Many come from this specific thread post : https://endless-sphere.com/forums/viewtopic.php?f=14&t=73701

Jestronix said:

Matador said:

Wow, love the thing! Now I'm thinking i should build my 18650 pack inside such a wind tunnel to keep it cool . Heat goes up, so one fan sucking air in at the bottom of the pack and one fan on the to top of the pack to poush the hot air put of the pack. That'd be crazy..

Click to expand...

I had the same thought, but in reality u shouldn't be pushing cells that hard! Then again tesla actively cools their cells, pushing too hard ? I'd say they do it for longevity, proabably reducing the total temp swings, or is it just for ludicrous mode ?

Click to expand...

I was thinking, something like :
http://gizmodo.com/5973061/this-computer-is-cooled-by-a-wind-tunnel

Just a little bit on the smaller side LOL.... O maybe I can take advantage of a small air intake scoop in the front of the bike