Kuhn Fertilizer Spreader Battery Pack

Kuhn Fertiliser Spreader Battery PackThe Siku Kuhn fertilizer spreader was one of the first accessories I bought for my RC tractors and I had always planned to use it and the butterfly mower as battery packs.

My initial attempts at tractor conversions left no space for a battery in the models because I used through hole components an larger servos which took up way too much space. As a result I was expecting to need to provide power from a source external to the tractor and I taught a 9 volt battery would work perfectly. Since then I’ve miniaturised the design and have a bit more space to play with so I changed to 3.7 volt LiPo batteries instead.

The fertilizer spreader is an obvious choice for a battery pack because it is basically just a spacious box with a hinged lid, you really couldn’t get a more suitable attachment.



Cost Breakdown

Component Quantity Price
SIKU Kuhn Fertiliser Spreader 1 €8.00
5 x 3.7V LIPO Battery + Charger Set 1 €11.42
Male Dupont Pins 100 €0.88
Single Pin Dupont Housing 100 €0.88
Total (Only used one battery and two Dupont connectors  in the build) €11.00

Components


Design

There is really nothing special about this build, I first drilled a small hole in the rear of the model to let the wires through, added a Dupont connector to one end because I use those on the tractor and threaded the wires through. Originally I put a 9 V battery connector on the other end of the wires because I had voltage regulators in the tractors but when I upgraded the tractors I settled on a 3.7 V design so I also upgraded the battery pack. I simply cut away the 9 V battery connector and soldered a 3.7 V LiPo battery there instead. This gives it way more power, around 650 mAh at 3.7 V compared to around 100 mAh at 9 V so it will last much longer.

Original Kuhn Battery Pack

Original Design

New Kuhn Battery Pack

New Design


Kuhn Fertilizer Spreader Video

There is one video of this simple battery pack which shows me upgrading it from my original design which used a 9 V battery into the design which works with my new tractor configuration using the 3.7 V battery.

Click here to see the Fertiliser Spreader Video