With the long, cold winter nights well and truly on top of us now, I've found it increasingly more unlikely that i get to go out with my models lately, and sadly even tough we had a nice bright and dry weekend last time round, i was unfortunately busy elsewhere and got no R/C time.
As a result i decided to set my LiPo’s into their storage state while they are going to remain unused for a while.
With it being the wetter months too, it makes sense to keep the electronics out of the way! I'm still bitter about myself when i blew my Flux Blur ESC recently!
So how do you store LiPo’s?
This i find is another slightly grey area about LiPo usage, depending on what you read exactly on the Internet.
When LiPo’s are to go unused for a length of time (at least a month) you should put them into the storage state, in order to keep the cells conditioned and maintain their life cycle.
Some people will argue that the batteries should remain fully charged at 4.2volts. Others say that they should be charged to a specific value.
The method that follows the latter argument, normally involves maintaining a charge of approx. 3.7volts. Which to me makes a deal of sense as this is commonly the nominal value of LiPo cells.
So this is the method i have used personally, and a it pays here to have a good quality digital charger. I used my XMove 2.0 to take care of this, which includes a specific storage cycle. Making it a simple case of choosing the desired cell voltage (conveniently it defaults to 3.7volts), plugging the battery in and press go.
A while later the charger buzzed to inform that the task was complete, and i bundled the batteries into LiPo safe bags and a secure container.
This isn't the end of the process though, you shouldn't just pack them away and hope for the best when you need them in future.
Ideally once a month you should take them out of storage and perform a full balance charge on them, discharge them (run in a model if you get the opportunity) and then restore them to the storage state. This should help boost the integrity of the battery and its cells.
Again, its a theory shrouded in mist, with no real black and white correct answers, in which case you own experience will play a big part.
To summarise the method.
- Storage charge cells to 3.7volts
- Store batteries in adequate containers
- Once per month, fully charge to 4.2volts, discharge (use), storage charge back to 3.7volts.