This thread may help a bit:
http://www.rcindia.org/batteries-and-chargers/traveling-with-lipos/?all. It is more specific to the USA though and I am not sure about the regulations here. However you choose to carry it, a LiPo safe bag is a must as you said. The Air India website says:
Battery cells in any electrical / electronic items are permissible now & will now not be removed at the security point. Loose battery cells / dry cells carried in the hand baggage are liable to be removed and the airline would not be in a position to hand over the same at the destination. Please carry the same in the checked baggage.
The Jet Airways website says:
Carriage of dry cell batteries, knives, scissors, sharp instruments, tools, fire arms, ammunition, and their toy replicas is prohibited in the passenger cabin.
It also says this regarding Lithium Ion batteries:
Carriage of Spare Lithium Ion Batteries
Spare Lithium ion batteries may be carried as checked in or cabin baggage provided they are installed within and connected to the accompanied device. Carriage of spare Lithium ion batteries without an associated device or disengaged from the associated device will be permitted only as part of cabin baggage. Only Lithium ion batteries of watt-hour (Wh) rating above 100Wh but not exceeding 160Wh, will be permitted.
Spare batteries must be individually protected by ensuring each one is placed in the original retail packaging or by insulating the terminals, e.g. by taping over the exposed terminals and placing each battery in a separate plastic pouch to prevent short circuit.
Spare Lithium Ion Batteries will not be permitted as part of checked in baggage.
On this website though (
http://www.dpreview.com/forums/post/50260014) it says:
1. ***ALL*** batteries must be packed in the checked luggage . . . BATTERIES cannot even be in the camera itself in your carry on bag. . . the "battery-less" camera can be in the carry on bag. Any batteries found in a carry on bag whether in the device or not will be confiscated.
This is pretty confusing. Maybe you could try calling the airline and asking