A word about batteries

[Admin]

Let me start by saying that if the AR Drone is your first brush with LiPo (actually LiOn) battery technology and you don't possess a specialist LiPo charger, then stick with Parrot batteries and charger because even though they are relatively expensive at £34 (at the time of writing) you are unlikely to fall foul of charging accidents and any resultant fire. However, if you're comfortable charging Lipo cells, read on ...

The Battery supplied with the AR Drone 2.0 is different to that supplied with the original and so is the charger.  The original Drone/charger had a separate balancing lead along with the ubiquitous +ve/-ve leads but with the 2.0 the balancing connectors are integral to the battery case which then latch into the charger. It's actually pretty neat but it does mean that only Parrot batteries can be used with the Parrot charger and vice-versa. So are we locked into using Parrot batteries or are there alternatives?  Well yes there are ...

The supplied battery pack is a 3 cell, (3S) LiOn pack at 11.1 volts and a capacity of 1000mAh with a discharge rate of 10C and a charge rate of 1C and, apart from it's physical balancing connectors, there's nothing "magical" happening inside the battery despite what might be written on certain other forums.  The magic however happens in the Parrot charger and inside the Drone itself and that "magic" is all about the longevity of the cells and charging safety.

In a nutshell, the Parrot charger actually charges slightly below the rated "1 amp for 1 hour" level, hence the charging takes a little over 90 minutes and the Drone hardware/software doesn't allow the cells to discharge to anywhere near their minimum (safe) voltages.  You may also notice that a fully charged Parrot battery only shows around 90-95% on your iPhone/iPad or Android device and that's because the charger only lets it get to that level - another safety thing I guess but the upshot is that your flight times will be reduced accordingly compared to a good quality off the shelf Lipo battery charged and balanced with specialist charging equipment.

I have just tested a regular 1000mAh LiPo pack which I fitted with a Tamiya mini-connector and charged with my BC6 charger and not only does it show 100% on my iiPad but it actually stays in the air a full two minutes longer than the Parrot battery - so that's about a 20% increase in flight time.

The limiting factor as to what battery pack you can fit is physical - both in terms of dimensions and weight.  The Parrot battery measures 72 x 39 x 24 mm and weighs-in at a very respectable 104g and I would suggest that whatever battery pack you buy, try to keep it as close to this as possible.  You may also wonder if it's worth upgrading to 1300mAh or even more - well yes it probably is but because the motors will have to work harder all the time to keep the Drone off the ground, it's unlikely a 1300mAh pack will give you too much more flight-time over the 1000mAh. I will buy a 1300 pack and test it though.

Typically you can buy a good quality 3S Lipo pack for around $10-$20 but do check the weight, physical dimensions and maximum discharge rate (which should be 10C as a minimum - physically you really don't want to shoe-horn anything larger into the battery box as this could mean all sorts of things for stability and "crashproofness" but you can probably buy 2 or 3 good LiPo packs for the price of a Parrot pack then just add a few pence for some mini Tamiya connectors and the job's a good un!

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While we're here then, we may as well also mention flight times and I write this for people who maybe aren't familiar with these things and have perhaps arrived here via Google ... flight times with the "outdoor hull" will be longer than with the "indoor hull" because it weighs a little less and flight times on calm, wind-less day will be longer then those where there's a bit of a breeze, simply because the motors have to work much harder to maintain stability and altitude in these conditions. Of course, the more you zip about and perform 'flips' the shorter flight you will get.