Hello,

I have two keyfob cameras from Hobbycity, the old SD resolution ones. Their code is #7, the worst of the lot actually. #3 was far better.

These cameras have a built-in battery, that is a 1-cell Li-Po with 140 mAh capacity. You charge it from USB-port. As far as I know traditional USB ports supply maximum 500 mA current. So this would charge up in roughly 17 minutes. I am very unsure how good the battery charging circuitry is in the unit. I would assume not so good. The premature death of my battery underlined this thought.

I was reluctant to just dispose the unit. It costs 15 USD, so quite cheap. But why dispose something if there is a chance of mending it. So I tried.

The idea was to buy a small Li-Po battery (done), and some JST connectors. So that I could remove the small battery, solder on the JST female connector and then use the external battery with some adhesive velcro tape. Brilliant 🙂

I tried to solder the contacts onto the wires. These wires are very thin, so use a fine grade soldering iron. Mine is very coarse, had to be very cautious.

When you have soldered the wire onto the metal pin you have to push together the last portion that forms an open U-shape. Otherwise it will not enter the plastic connector housing.

Then I had to remove some material from the other half of the housing. To have a good support for the connector I removed a rectangular area.

The connector fits nicely.

I double checked the polarity to be sure. Then I could assemble it and glue in the connector. It will be subject to some force when connecting and removing the outside battery. I used CA glue.

Just a size comparison, the new battery next to the camera unit. I will use adhesive velcro to fix it on top.

Maybe I will have the battery on the plane and the camera will sit on the battery. This way I will get better (less) drag coefficient. Important in flight.

I will need to do this on my other camera, that has reduced battery life. Probably will throw in the towel soon. Since this new battery is 240 mAh (vs 140 for the original) I will get significantly better battery life. And I can monitor the cell voltage with my Cell Voltage Monitor device. Important factor in keeping batteries healthy.

Best regards,

Sir Crash a Lot