Balance charging for the Fatshark battery case: Mod Tutorial

Recently I made my biggest ever FPV purchase - the Fatshark attitude V5 FPV goggles with the new 30 degree FOV OLED screens. I'm still field testing these for a review which will follow but first I wanted to look at the battery case, more to the point, how to fix the shortcomings.

The Fatshark 18650 battery holder comes with the Attitude V5 or can be bought separately

I love that you can use 18650 cells to power the goggles because lithium ion cells are much better suited to the task given their big capacity. The problem is that the battery holder has an incomplete balance connect meaning you cannot charge them. Since I don't have a dedicated 18650 charged I've modded my case so it can be charged safely using a regular balance charger. Note, the Fatshark 18650 battery holder can be bought separately here and can be used with any goggle.

In this tutorial I rectify this issue by showing you how to safely open the case and mod it to allow for real balance charging whilst losing noe of the rest of the functionality. With this mode you do not need a special charger for 18650 cells, you can use your regular balance charger and charge your pack safely and efficiently. If you need batteries a local vape shop will probably have the best prices but if not then I used these 3000mah ones that have been rebranded.

Tools needed

• Craft knife
• Small Philip-head screwdriver. This set looks good if you don't have one.
• Soldering iron. I use the excellent TS100
• Solder. This is fine
• Flux (optional but recommended). I use this cheap stuff
• An old battery-end balance lead. Or if you buy this one you won't need the extra wire below
• Some extra 20-26 guage wire. This is cheap in 22AWG

See below how to complete the work. This took me about 30 minutes. Most of the time was to figure out the best path for the wire and make the path for it accordingly. As always, pictures can be embiggened

1. Remove the read sticker and then remove the 2 screws that were hidden behing  the sticker. Gentle pry the clips off to remove the cover as above

2. Slide out the battery connecting plate as above

3. Tin the battery connecting plate as above. Scrape where you wish to solder, use high heat and flux to make it easier

4. Solder on a 20-26AWG wire that is at least 10cm in length

5. Reinsert the battery connetor plate as above. The wire should be attached by the hinge

6. Using a small flat head screwdriver pry off the plastic plate that locks the rubber grommet in place

7. Using an old battery-end balance connector, pry out one pin and wire and then feed it into the middle of the fatshark balance connector. Feed the wire through the grommet and into the case.

8. Gently replace the plastic plate that locks the grommet in place.

9. Join the wire from the battery connector plate to the one you fed through the grommet from the balance plug. Use solder and heatshrink as above. Please test the balance and power lead in your charger now - it should show as 2 cells

10. Route the wires above. You will need to make a path for the wire to pass through compartments by using the soldering iron to melt or knife to cuth the plastic before you can put the cover back on. Make sure the door opens and closes freely.

11. Reinstall the cover. You can see some slack in the wire here that allows the door to be opened and closed easily.

Charging
Now for the easy part - charging. Since you will already have a balance charger for your lipos, this is the ideal charging unit for it. Just make sure you select Li Ion as the cell type for charging which means charging is typically limited to 4.1v per cell. Unlike LiPo batteries you should charge at a maximum of 0.5C e.g. 1.5A for 3000mah batteries or 1A for 2000mah batteries etc.

Did it work?
Yep! Beautifully - just as I'd hoped. Charging went flawlessly - my 3000mah calls took 2600mah charging from 3.4v which sound about right. The battery indicator works perfectly too. Given the capacity of these batteries they will probably never come out of the case - I will just charge them up in the case as they get low. I honestly don't know why Fatshark don't do this from the factory but then again there are a number of curious design decisions which I'll comment on more in my goggle review.

​Thanks for reading, if you found this article useful please feel free to like or share, the facebook links below directly link/like this article. Links are affiliated and help me buy the bits I need to produce this type of content.

Coming soon: Fatshark Attitude v5 review and comparison to the Aomway Commanders