DC booster helps double field time for COX 010 micro RC planes

balogh Sun Oct 08, 2023 9:38 am

Intrigued by the low-weight battery arrangements by Brad aka 1/2A Nut, and Robert aka rdw77 in their small COX RC planes, I looked around on the local hobby market, and found a cheap DC-DC converter type MT3608, or booster, that can boost as low as 2V input voltage to as high as 20 V on the output.

DC booster helps double field time for COX 010 micro RC planes Mt360811

https://www.ebay.com/itm/225734625755?hash=item348ed509db:g:KyAAAOSwsvhk3-ur&amdata=enc%3AAQAIAAAA8CUq0aBDnjdYLS3WLa%2BSeBDeLoh3PvtDkAX6lYxbMNixGDZ1C0SlSMkdvExMazoSLhMlBMWyU6seSQa82fGnFEmKm1bOoimj3lgo3cuhn7p8hgtqE7onhz0lnWTn%2FohUzDlF%2FkRqZstqyO%2FTt3GefTaoVDpVuOj5KohF1Dn6APle4L0bNKIM6ta4NYU0JdHJQq5cFItTJFC6CdzN70TzB4cJDZlcbw8vvq71QaSxovrMTIqlTta%2BVQefwFrveIVeJJvVQBT2ZKdIeIlbWQYEmqgyQ4nPMaXrcCiFixU%2B5VoVO0MsIuJmBjWskUXnbXmf7Q%3D%3D%7Ctkp%3ABFBMkoW5--Fi

Brazed to a 1 cell LiPo battery of 3.7V and 380mAH capacity, I have a power unit that will generate approx. 280mAH set @ a voltage ramped up tp ~5V, i.e. near double the mAH a standard NiMh battery of 4.8V and 150mAH provided to my planes before, at the same 17 grams of dead weight added to the airframe weight, as the 150mAh NiMh battery with short cable added in the past.

DC booster helps double field time for COX 010 micro RC planes 20231013

The good thing about this booster is that with its small copper screw on the blue module, one can adjust the outlet voltage to his needs:

DC booster helps double field time for COX 010 micro RC planes 20231014

With the LiPo a bit overcharged at 3.99V, I set with the screw an output Voltage of ~4.97V

I have mounted this power unit into my Lil' SpeeDee powered by a COX TeeDee 010 and field tested it. The output Voltage ~4.97V remained constant even after 4 flights of 8 minutes each, with the input voltage from the LiPo only slightly dropping.

rdw777 Sun Oct 08, 2023 5:27 pm

Andras, That looks like a great solution to get more capacity for the same weight as the previous system!…. I haven’t seen a “step up” electronic gadget for our applications but I suppose in practice it is similar to what I use in a “step” down” format, Two cells and a 5 volt regulator….Regardless, It is great that we have access to these components and they are relatively inexpensive….

When I get back home from a flying outing I put the cells on a home made discharger and pull them down to 3.7 volts per cell at a 70 mA load to see how much capacity was left in the cells…. 150 mAH cells in Pageboy and 300 mAH’s in Zoomslot…. Each plane usually flies three or four times….I find that usually about half the capacity was used in each plane….

About once per month as a maintenance, I discharge all my cells from full to 3.7 volts and note the time…. It helps to give an idea if any are losing capacity….. Then return them to storage voltage at about 3.75 V…..

Glad you were able to make a performance improvement on Lil’ SpeeDee…. Looks efficient…..It might end up being your go to power arrangement on others…. I like to continue to explore options for improvements as well….. Keeps our little flyers interesting Very Happy

balogh Sun Oct 08, 2023 5:48 pm

Thanks, Robert, indeed I have always been bugged by the unknown but certainly not too much stamina left in my small NiMh batteries after 2-3 flights of 8 minutes each, remembering 1 or 2 planes I lost historically due to the on-board battery running low. Now I can be sure the LiPo will last longer in the field. Funny thing is that they also sold me a USB cable with the right socket for the 1cell Lipo battery, so I can charge it in the field from the cigar lighter connection through a phone charger or any if the USB sockets of the media system in my car...1cell LiPo batteries do not need a balancer so their charging is very simple.

In addition I tried my hands on brazing miniature connections and even if not nice, they ended up functional! Very Happy

Sponsored content

DC booster helps double field time for COX 010 micro RC planes

DC booster helps double field time for COX 010 micro RC planes

Re: DC booster helps double field time for COX 010 micro RC planes

Re: DC booster helps double field time for COX 010 micro RC planes

Re: DC booster helps double field time for COX 010 micro RC planes