X4 - Minimum number of 7S batteries needed to fly

Greetings all,
For my X4, I originally had 4 Bonka 7S batteries. However, I inadvertently shorted one out; I only have three now.
Can an X4 fly with three or just two batteries? And… how would I string them together?
I have to admit… I’m not battery savvy… I would love to see a couple example images of how the batteries should be connected to one another and to the leads of the X4 itself.

Thank you in advance to any assistance provided!


The batteries must be used in pairs so you can’t use three. Two batteries would overheat quickly. I recommend using six.

This forum has a search feature that works great for finding examples like you are asking for.

That sounds like it was… exciting.

Yeah you need an even number to pair them in series. Essentially your X4 is designed for 14s. We use pairs of 7s because its easier to source 7s batteries and chargers.

Did you ruin the entire pack or just the connectors? If you short it out the connectors you will fry the connectors which can be replaced as long as there isn’t damage to the pack.

I inadvertently plugged the single battery’s own black and red connectors together. Big POP sound and the two connectors melted.

I have not tried replacing the connectors… I figured it ruined the battery. But, the battery is not showing any external damage besides the two connectors.

Anyone know if there’s a fuse built into the packs? Even if not you may have been lucky enough to have melted a connection apart before the cells got damaged. Probably couldn’t hurt to very carefully unwrap it and take a look. Very carefully! Also, have you checked the cell voltages via the balance taps?

Connecting the positive and negative together will create high amps for a very short period of time because the connectors get fried so fast. Unless you try to hold them together while they are arcing and popping the pack itself should be fine. Check the exterior for damage from the sparks. Check the voltage of each cell. Make sure there is no swelling. If all is good just replace the connectors. No need to open the battery.

Running an X4 with only two packs at full throttle for a few minutes will do more long term damage to the cells than a quick high amp spike.

There’s not a fuse in the packs but the connector gets damaged so fast that it acts like a fuse. I accidentally did the same thing once. It arcs and startles you before you have a chance to get the connectors fully together and makes a huge mess of the connectors.