I’ve been testing the ISDT BattAir LIPO for 3 weeks -here’s the pros and cons

Last month, I won two pairs of their BattAir smart LIPO batteries on ISDT’s giveaway. As they are known more for their hobby chargers, I expected to receive their newest K2 Air or Air 8 inteligent charger.

Unlike DJI batteries, FPV batteries are dummies and do not have any smart features; there are just a bunch of LIPO cells connected serially. Power tool batteries such as Makita and Bosch have had for a long time smart batteries that allow monitoring through a mobile application. ISDT thought, why can’t FPV batteries have such capabilities? Why do we have to use battery checkers instead of being smart?

The ISDT BattAir packs come inside with a tiny Bluetooth module that monitors individual cell voltage, temperature, and other parameters. You can check your LIPO’s charging level without connecting any device (balance voltage checker) from your smartphone; even the packs are in your backpack. Specifications such as manufacturing date, C-rating, max charging voltage, and recommended charging current are also stored in the module.

ISDT BattAir review

As mentioned, ISDT sent me a pair of 4S 1500mAh and a pair of 6S 1300 mAh smart battery packs. These batteries are commonly used on 4 to 6-inch FPV drones. They have the best weight/flight time ratio. Both batteries come in a nice fireproof bag that can store up to four batteries. I recommend using the bag, especially when you are charging the batteries. Each battery is double-wrapped in bubble bags for extra protection.

The 4S 1500mAh BattAir LIPO measures 36x35x82mm, and the 6S 1300 mAh 34x47x80mm. Both have transparent wrapping so you can see the individual cells inside the pack. Additionally, on the top part, where the cell connections and the smart battery’s brain (Bluetooth module) are, is a second layer of black wrapping. Both BattAir packs have a 9cm XT60 discharge (drone) cable and a 4cm balance cable.

Two sides of the pack have an aluminum plate for extra protection during a crash -you should install the battery on the drone with these sides most exposed. I crashed my iFlight Chimera 9 onto my roof a few weeks ago due to the wrong BetaFlight configuration. The impact with the tiles was so hard that one of the battery cells was punctured and caught fire instantly after contact with air.

If you do the math, the 4S (14.8v) 1500mAh pack has a power of 22.7Wh, and the 6S (22.2V) 1300mAh 28.86Wh.

ISDT BattAir series batteries

When I published my review, ISDT had only four “smart” LIPO batteries: a 2s, a 3, a4, and a 6s. They told me that soon will be released other cell\capacity options as well. Furthermore, they started to work on the second-generation BattAir v2, which hopefully will have a higher discharge rate (100C or more) to fulfill the power need of racing and freestyling FPV drones.

BattAir App

The BattAir APP is available for both Android and iOS devices. The APP is minimalist, and you feel it is still developing.

From the APP, you can monitor all your batteries at a glance. Besides charging level (in percent), total voltage, individual cell voltage, and temperature are also shown on the details page. The cell(s) with the lowest voltage and the one with the highest voltage are highlighted with different colors. You can add a name to each BattAir pack for easier identification.

To reduce power usage, the Bluetooth transmission can be turned off after a specific time and wake up when needed by shaking the battery pack. Shaking sensitivity can be adjusted to avoid accidental triggering.

The batteries arrived with firmware version 2.0.1.29, and the APP prompted that an update was available (2.0.1.34).

ISDT BattAir LIPO performance

Before any tests, I performed five cycles of charging/discharging at 1C (1.3A and 1.5A).  BattAir FPV batteries can be charged with any smart charger, but of course, ISDT recommends using one of theirs. The 4S 1500mAh charged to 1408 mAh (from 3.2V to 4.2V), and the 6S 1300mAh to 1241 mAh.

During the break-in process, I noticed that the fifth cell behaved abnormally in one of the 6S packs; when the voltage went below 3.5V, it started to collapse, which normally should happen under 3.2V. At the end of the discharge process, the pack had a voltage difference between cells of 0.6V, which is huge! Internal resistance (IR) also doubled in that cell (see photo below).

Both BattAirs fit perfectly for my FlyFish VD6 long-range FPV drone, leaving space for a GoPro camera. The average flight time with the 4S pack was around 5-6 minutes, and with the 6S, 6-8 minutes. I mostly cruise with gentle throttle usage, so the 85C discharge rate is more than I need.

After every full charge, the number of “cycles” is indexed by one, so you know how many times the battery was used before and how long you can trust them. Based on my experience, after 2-300 or so charge cycles, most LiPo batteries start losing much of the initial performance, and it is time to retire them. Poor-quality packs can even puff after a few usages, and you should immediately stop using them. My BattAir packs have between 10 and 20 charges, and they behave and look normal for now.

Pricing and availability

The BattAir batteries were manufactured in a small quantity to prospect the market. These smart batteries are not even available on the company’s online store. If you are lucky, you can find them in stock on Amazon. When I published my review, the 4S 1500mAh was available for €39.99/pair and the 1300mAh for €61.99/pair. These prices also include the fireproof bag. The BattAir plugins that can turn your standard LIPO packs into smart batteries are available here.

Smart BattAir LIPO vs Standard LIPO: Size, weight, discharge rate comparison

Because the design and construction of BattAir LIPOs and standard LIPOs look the same, it’s hard to tell the difference. Compared to standard LIPO packs, BattAir batteries are generally larger and heavier for the same capacity. They are hefty due to the extra hardware inside and those aluminum side protectors.

With a max 85C discharge rate, BattAir smart packs are excellent for cruising FPV drones, but if you need a battery for racing or freestyling drones, you should look for an LIPO with 120-150C.

Turn smart your existing LIPO batteries with the iSDT BattAir Plugin

ISDT also has a little device named BattAir Plugin that connects to the balance port of any LIPO battery and turns it into a smart battery. The BAP2 module is suitable for 2S, the BAP4 for 3-4S and the BAP6 5-6S batteries.

The Bluetooth LIPO monitoring dongle uses the same mobile app and provides approximately the same features as the ones built into the BattAir packs.