How Long to Charge Airsoft Battery 8.4 V

Li-Ion cells such every bit 18650 or 21700 have college energy density than LiPo (more capacity mAh for the same weight), they make bully bombardment for long range flying. I volition recommend what to purchase, and also show you how I built a 4S 18650 Li-Ion bombardment from scratch.

Further Reading: Here are my tips on long range FPV flying.

Differences Between Lipo and Li-ion

There are 3 master differences:

Energy density
Belch rate
lowest safe voltage

Li-ion bombardment packs are culling to the nearly mutual Lipo batteries. Comparing similar size packs, Li-ion has virtually double the capacity.

lipo vs li-ion for FPV flying size comparison

Left: LiPo 4S 1500mAh; Right: Li-ion 4S 3000mAh (18650)

LiPo batteries accept much college discharge rate than Li-ion, meaning you can become much higher current out of them. To give yous an idea, typically a high quality LiPo have around 30C to 40C of continuous discharge charge per unit, while Li-ion merely has 5C (What's C rating?)

Lastly, you can usually discharge a LiPo down to three.5V per jail cell safely, notwithstanding Li-ion tin go much lower, e.thou. iii.0V per cell. Both battery types can be fully charged to iv.2V per cell.

The Pros and Cons of Flying Li-Ion Bombardment

Li-Ion bombardment has college capacity than LiPo for the same weight. The 4S 18650 3400mAh I built, only weighs 203g, while a 4S 1600mAh LiPo has virtually the same weight. On newspaper you lot should get double the flying time!

Yet, the maximum discharge rate of Li-Ion battery is not great compared to LiPo, that's why it'due south not a popular battery choice for FPV drones. If you lot power an FPV freestyle drone with Li-ion, it will experience very weak and slow.

For long range aircraft however, it'due south a not bad option because they don't crave a lot of current. If you lot use an efficient ability system, Li-Ion cells can totally handle information technology.

In fact, Li-Ion battery has been popular in RC fixed wings / planes every bit they normally simply use one motor. Information technology's besides possible to use on highly efficient quadcopters. I tested a long range quad that weighs under 250g. With a 4S 18650 Li-Ion battery I custom built, i was able to get near half an hr of flight time :) It's pretty incredible! But it doesn't accept the power to perform crazy acro moves, I was only able to cruise around about of the times and exercise a few flips and rolls hither and at that place.

What's 4S1P and 4S2P?

4S is the nominal voltage of the pack, i.e. how many cells are connected in series. 2P is how many cells are continued in parallel. 4S1P has four cells while 4S2P has 8 cells in total. They both have the same nominal voltage, but 4S2P will be able to provide double the current, chapters and weight.

Buying Pre-made Li-ion Battery Packs

If you don't desire to brand your own bombardment packs, you can just buy them off the shelf.

3S

ZOHD 3S 3500mAh (Max 10A ): https://oscarliang.com/product-95k5
Auline 3S 3000mAh (Max 30A): https://oscarliang.com/product-goi0

4S

Auline 4S 2600mAh (Max 35A): https://oscarliang.com/product-3lok
GEPRC 4S 3000mAh (Max 30A): https://oscarliang.com/product-c4vy
ZOHD 4S 5000mAh (Max 10A): https://oscarliang.com/product-idr5
Auline 4S 6000mAh (Max 60A): https://oscarliang.com/production-lp7e

6S

Auline 6S 2600mAh (Max 35A): https://oscarliang.com/product-gtu2
Auline 6S 3000mAh (Max 30A): https://oscarliang.com/product-zguf
GEPRC 6S 6000mAh (Max 30A): https://oscarliang.com/product-ws6b

Things You Need To Build Your Own Li-ion Battery

Hither is the wiring diagram of a 4S Li-Ion bombardment pack with XT60 and balance connectors.

Note that at that place are two main types of Li-Ion cells we use, 18650 and 21700. The numbers are basically the dimension of the cell, 21700 is heavier and physically larger, and so is its capacity.

I am using 18650 here because information technology's generally more mutual and widely available online.

Sony VTC5A (US18650VTC5A) and VTC6 (US18650VTC6) are the popular choices, with chapters of 2600mAh and 3000mAh respectively. VTC5A has college discharge rate (25A) than VTC6 (20A), but slightly less flight time. I am using Panasonic NCR18650B in this build log only because I have some spare. They are okay for powering FPV goggles, maybe some low power builds too, but endeavour to go the VTC cells if you tin, they have much improve functioning.

Buy 18650 Batteries Here:

Sony VTC5A
Sony VTC6

You volition also demand some wires (I am using 16AWG for the discharge lead and 20AWG for residual lead), every bit well as 5-pivot remainder connector and a XT30 or XT60 connector. XT30 should be fine, but XT60 might exist more than convenient if that'south what you employ on the drone.

Buy XT30 Connectors Here:

GetFPV
Amazon
Banggood

XT60 Connectors

GetFPV
Amazon
Banggood

Buy sixteen AWG Wires Here:

Amazon
Banggood
GetFPV

Buy Residual Connector Here

Banggood: http://bit.ly/2NOtWwi
Amazon: https://amzn.to/2AlClFK
GetFPV (4S): http://bit.ly/2K01jtT

Buy Heatshrink Here

Transparent Heatshrink (go the 86mm)

How I Built 4S 18650 Battery

Disclaimer: Soldering on battery is unsafe, if you lot make up one's mind to follow instructions in this mail service, do and then at your own take a chance.

Solder wires to the connectors, I use longer wires than I need, and I can just trim them to the length I want later on.

Soldering wires to the 18650 cells according to my wiring diagram. You should definitely check out my tutorial on how to solder 18650 batteries safely.

Here's the top side.

build 4s li-ion battery for long range flying solder balance discharge xt60

Here'southward the bottom side.

Cover all solder joints with electrical tape then finally wrap it in heatshrink. And aye, you can probably use a shorter discharge atomic number 82 to save a couple of grams, I fabricated it longer on purpose.

build 4s li-ion battery for long range flying

The 4S 18650 battery weights 203g, and I become about 30 mins of flying fourth dimension from it on the Flywoo Explorer LR 4″: https://oscarliang.com/flywoo-explorer-lr/

li-ion battery for long range flying fpv drone

Edit History

Aug 2020 – article created
Mar 2021 – added production links to where you can buy Li-Ion packs directly