no matter what the condition of the LiPo battery it is always a good idea to store and transport them in a bag that is insulated and fire proof that are specially made for that purpose. Len

You're a braver man than me!

Mine are relatively new but I was still anxious before going away on a recent 4 week holiday. But after a careful inspection, checking the internal resistance and recharging to the storage voltage I was happy.

Do bear in mind that even if OK, over time and number of charges their performance does decrease.

I have always tried to get my lipo's to work before I look at new ones some of my lipo's are from when they first came out.

Well done Len1, well said.
If we break electronic devices we feel very sorry because we waste money, if we ruin our models we despair because we throw away the time and passion we have dedicated to them, but if we get hurt or set fire to the house it is much worse.
Even if things have improved a lot today, they must be treated with care and caution.

as has already been stated and I wish to emphasize is that trying to bring a completely dead or extremely low voltage LiPo back by charging can be very dangerous. Len

Lipos have to be stored at no less than 3.8v per cell otherwise as stated they are scrap.

Chris

Hi ColinH, you're welcome.

If it's any consolation, even here in Italy the areas are almost all closed to drone flying.
It is very difficult to find a free one.

I have the A1, A2 and A3 (these are the European qualifications) but I don't have my own drone.

I wish you a lot of fun with drones.
Imagine how much fun it would be if you filmed your models with the drone while your nephew piloted them.
We are more children than them, hahahaha.

For batteries, my thought is that lithium technology is exceptional.
It has excellent performance and features.
For airplanes and drones it is the best solution.
However, I don't think I will ever use it on ships, because I am still very wary of lithium.
On ships I have no need for lightness and I can achieve good autonomy with other technologies.
For now I'm sticking to lead acid batteries from the VRLA (Valve Regulated Lead Acid) family, AGM (Absorbed Glass Mat) subfamily, which are cheap and easy to recharge.
I used technical thermals but more simply they are the common batteries that we use in alarm control units and a thousand other uses, such as 12 Volt 7Ah, 6 Volt 4.5 Ah etc. etc. By mistake I did things to it that if it had happened to the lithium ones they would have exploded or caught fire, but instead these just swelled out of all proportion.

P.S. I used DJI products some time ago. In this commercial segment of drones they are ahead of everyone or at least among the first. They have reached a very high level of technology and performance.

Thanks Alessandro, I thought someone would know. I have managed to revive ancient sla, nicads and nimh. But have no experience of lipo's at all.
I have just been given 2 very good quality camera drones for spares or repairing.
1 had a broken wire, and the other has been left in an attic for 3 years but it works fine, I tested it with the battery from the 1st one.
So looks like I will have to buy some replacement batteries for that one.
This is a totally new venture for me, drones are good for photography and hopefully I will be able to get video footage when sailing boats. First I need to learn to fly them, I used to fly rc planes and helicopters, but drones seem a lot easier to control, with auto hover and pre-programable flight patterns with auto return to take off position.
I feel like a kid again, my only problem is I can't fly in my home garden as we live in a restricted air fly zone. I was testing in my garden when we were visited by the police to tell me not to fly.
So going to a friends farm at weekend to see how well they do.
Cheers Colin.
P.S. they are DJI phantom 3's.

Most likely NOT Colin.
If the cells register NO Volts (ZERO) or only a few mV then irreversible chemical changes have taken place.
It may possibly even be dangerous to try, but I doubt that if the battery registers zero energy.
Sorry, 'fraid you're gonna have to fork out for new ones🤑☹️
Cheers, Doug😎

Hi Colin.
I'm afraid that after three years completely discharged (if I understand correctly), they are now dead.
I would be very surprised otherwise.