You may have noticed but Fatshark battery cells are sh*t. Whether they get them from chinese Landfill or try and charge them in the factory with a Laptop charger who knows, either way they are crap and not fit for use. To make matters worse they have the cheek to charge $25 for a 2S low C lipo. Whether Fatshark are just ignorant of how crap their product is or they just simply want to rip people in the hobby off, there is an easy fix to terrible Fatshark cells which is also handy for powering all goggles as well as RC devices:
The incredible NCR 18650B Li-ion Battery. This will not only give you more capacity, it is also lighter and cheaper than a Fatshark battery.
Heres one we made earlier for our Long distance Plane, bigger scale – same concept
You will need
- NCR18650B 3.7V 3400mAh 18650 Protected Li – ion Battery Rechargeable
- JST-XH 2S Wire Extension 20cm (10pcs/bag)
- 2.1 x 5.5mm DC Power Pigtail MALE
- Heat Shrink
Get two LI-ion batteries and make sure they are both 3.7 volts or at least within 0.1V of one another. As you are connecting them in series.
Place the left hand battery with + facing upwards and the right hand battery with + facing down wards. They should sit like that on your bench.
Using a wire or a metal plate solder the positive and negative at the bottom of the battery. This will connect them in series, making your battery into a 2S.
Next you need to connect the balance lead. This seems like the most daunting part but its actually quite simple.
In this Diagram I have placed the balance lead below so that you can more easily understand what is going on. However it is recommended you put the balance lead towards the top of the battery so it is easier to plug into a charger.
It is very simple. Place the balance lead towards towards the top of the battery (according to our diagram) then cut Red wire to ~3cm and the black wire to ~3cm + width of one battery. The middle yellow wire should be cut to the length of the red wire + the length of a single battery. Doing all this should ensure a balance lead with plenty of slack to be plugged into the charger.
Finally (follow the diagram) solder the:
- Red wire to the positive of battery 1.
- Black wire onto negative of battery 2
- Yellow / middle wire onto negative of battery 1
Now you need to connect your power leads. Make sure with a DC connector you do not reverse the popularities or you could end up frying your goggles. If possible buy pig tails which have black and red but if they do not, use a multi meter to work out the polarity or check online.
This is fairly simple to do. Simply solder the Red wire of the DC pigtail to the positive of the top side of the battery and the black wire to the negative of the top side of the battery. In general for goggles make your power lead about twice as long as your balance cable (better too long than too short).
Finally carry out the finishing touches by applying the heat shrink. A handy trick we find is to glue down the the edges of the heat shrink this why you neaten up the battery pack as well as sealing the positive and negatives.
Before you plug the battery into your FPV set, check all the connections with a multimeter!!!!!!!
As always stay safe and happy building.