Auxiliary Charge Fan: 2x 120 mm

I have been experimenting with auxiliary charge fans, and I made a 3D-printed bracket to hold 2x 120 mm fans.

I put the description and files on Thingiverse: www.thingiverse.com/thing:5961806

Here is something really interesting. Have you already done some tests? If so, does this system effectively limit the temperature rise of the charger?

Good job.
Where did you connect the fans to 12VDC?

I'm curious too about fans airflow.
Do the fans push the air down to the ground or upper? In the latter case how did you modify the plastic cover under the pedals?

Sherlock schrieb: Here is something really interesting. Have you already done some tests? If so, does this system effectively limit the temperature rise of the charger?

Not yet tested in full operation. It's still in development, although the 3D-printed parts are done. I will post here when I have some results!

villadsen schrieb: Good job.
Where did you connect the fans to 12VDC?

I plan to control the fans via the switched 12V output of the OVMS v3 "DIAG" port. Either directly, or via a relay. I haven't decided yet. The fans could of course be controlled manually as well. For example by putting a switch on the dashboard, and just switch on the cooling manually when charging. Then the OVMS would not be needed.

Delvecchio schrieb: I'm curious too about fans airflow.
Do the fans push the air down to the ground or upper? In the latter case how did you modify the plastic cover under the pedals?

I have not modified the plastic cover, or any other part (yet). Although the wiring is not yet complete. My initial plan is to push the airflow down, but the fans can be easily turned in the other direction if that works better.

There is about 30 mm open space between the charger and the floor panel. The fans have a thickness of 15 mm, and are held in the middle of the 30 mm space. That leaves 7-8 mm above and below the fans to pass air through the sides. I hope this will work out well, but I can't say for sure until it's properly tested!

I have not modified the plastic cover, or any other part (yet). Although the wiring is not yet complete. My initial plan is to push the airflow down, but the fans can be easily turned in the other direction if that works better.

There is about 30 mm open space between the charger and the floor panel. The fans have a thickness of 15 mm, and are held in the middle of the 30 mm space. That leaves 7-8 mm above and below the fans to pass air through the sides. I hope this will work out well, but I can't say for sure until it's properly tested![/quote]


I could imagine that a combination of your fans and the stainless steel cover from Ministromer www.ministromer.de/epages/83462716.sf/de...ectPath=/Shops/83462716/Products/TWLADER could be very efficient to evacuate up to the cabin the hot air surrounding the loader.

An update: I have now completed the electrical connections, using OVMS to control a relay that switches on the fans. I charged the battery this afternoon, while monitoring the charger temperature using the OVMS "12V battery history" feature .



I started charging with the fans controlled by OVMS . In this mode, OVMS switches on the fans above 45°C, and off when the temperature drops below 45°. My fans successfully maintained this temperature.

I then switched off the fans manually. The charger temperature rose to 54°. I manually switched on the fans, and the temperature dropped again.

The outside air temperature was about 10°C at the beginnging of the charge, 9° in the middle and 7° at the end.

That's all I have had time to test, but I'm happy with the results so far. Of course, I will need to test this again when the weather gets warmer!

Sherlock schrieb: I could imagine that a combination of your fans and the stainless steel cover from Ministromer www.ministromer.de/epages/83462716.sf/de...ectPath=/Shops/83462716/Products/TWLADER could be very efficient to evacuate up to the cabin the hot air surrounding the loader.

Interesting! Thanks for sharing this. I was not aware of this site, they have some other useful products too!

An update:

On a day with 15°C ambient temperature, the charger heated up to 50°C with the fans running. I did not test without fans on this day, but based on the 10°C result, my guess would be it would have reached 60°C without cooling.

I am exploring the possibility of installing a third fan above the charger. There is room for this, but it's more cumbersome to install than the two original fans. The charger has to be temporarily removed. This does not change the design of the original two fan mount, but adds some new parts. I will of course share the design for the new parts once it's finalized!

In a few days, I'll be able to test your two-fans-system combined with the stainless steel cover from Ministromer. I'll report too.

Guten Morgen,

Vor einigen Wochen folgte ich den Anweisungen von Tor und installierte mit der wertvollen Fernhilfe von Fabio die beiden Ventilatoren und kombinierte sie mit der von Ministromer verkauften Bodenplatte (dadurch wird der Luftstrom noch erhöht). Nach einer Reihe von Tests kam ich zu dem Schluss, dass die Luft von oben nach unten geblasen werden sollte und nicht umgekehrt. Die Ventilatoren werden völlich automatisch von ToM gesteuert. Ehrlich gesagt empfehle ich diese Einrichtung (die wahrscheinlisch noch verbessert werden kann). Wenn Sie Fragen haben, zögern Sie nicht sie hier zu stellen oder per PN.


Hello everyone,

A few weeks ago I followed Tor's instructions and with valuable remote help from Fabio I installed the two fans and combined them with the base plate sold by Ministromer (this will increase the airflow even more). After several tests I came to the conclusion that the air should be blown from top to bottom and not the other way around. The fans are controlled fully automatically by ToM. Honestly, I recommend this facility (which probably can be improved). If you have any questions, don't hesitate to ask them here or via PM.

Eine tolle Idee!
Ich möchte nur anmerken, dass hier nur die Temperatur am Kühlkörper gekühlt und gemessen wird.
Wenn aber keine gute Temperatur-Verbindung zum Transistor besteht, könnte dieser trotzdem noch überhitzen. Daher wäre es auch gut das Wärme-leit-pad neu zu montieren.


A great idea!
I just want to note that here only the temperature at the heatsink is cooled and measured.
However, if there is not a good temperature connection to the transistor, it could still overheat. Therefore, it would also be good to reinstall the thermal pad.

Vorbereitungen sind fertig. Nur noch der kabel + stecker fur das ovms :0)

Mfg RCoolen