You should discharge your LiPo down to 3.85V per cell for storage, and the Vifly StoreSafe is designed to help you do this without hassle.
Further Reading: Why Store LiPo at 3.85V per cell?
What Is Vifly StoreSafe?
It’s basically a battery discharger, similar to the one I built with power resistors, but the StoreSafe has a microcontroller that stops discharging when the voltage of the battery reaches a number that should be suitable for storage.
After a day of flying, you might have a couple of batteries that are still fully charged and not being used. The Vifly StoreSafe might come in handy to discharge them for storage. You don’t want to leave LiPo fully charged for a long period of time (e.g. more than a week) because it’s bad for its lifespan and performance.
The StoreSafe only supports 2S to 6S LiPo. Discharging power is 1W.
Where to Buy?
- Banggood – https://oscarliang.com/product-08nf
- GetFPV – https://oscarliang.com/product-7ho5
- RDQ – https://oscarliang.com/product-2uzc
- GetFPV – https://oscarliang.com/product-upki
- RDQ – Same link as above
- Banggood – https://oscarliang.com/product-6aug
There are two versions, XT30 and XT60. But apart from the connector, they are basically identical. I don’t quite get why they make two versions, they could just supply a XT60 to XT30 adapter.
How Does It Work?
Just connect your fully charged battery up to the Vifly SotreSafe. It will automatically detect the number of cells (2S to 6S), and start discharging. And it will just do its thing and stop discharging when it finishes.
It’s best to leave the Store Safe on a fireproof surface such as concrete floor as the heatsink can get pretty warm.
If you make a harness you can discharge multiple batteries at the same time. But of course this will be much slower as the total capacity is now larger.
Why You Might or Might Not Want StoreSafe?
It’s a handy tool to have, and it’s doesn’t make any noise like a charger. However, I can’t really recommend this products for several reasons.
First of all, most smart chargers these days can discharge LiPo to storage voltage (such as the iSDT Q6 and ToolkitRC M4Q), they can even charge them up to storage if they are below 3.85V per cell. However the StoreSafe cannot do this, it can only discharge batteries.
Secondly, it’s super slow as the discharge rate is only 1W, for a 4S battery discharging from 4.20V, discharging current would be around 0.06A only. It would take over 10 hours to discharge a 1600mAh down to half of its capacity! Some people say it’s great for the fields, yes if you plan to stay overnight out there, maybe. But hey, at least you don’t have to watch it as it’s automatic.
And let’s talk about its biggest downside – the lack of cell balancing!
For example, we expect it to discharge a 4S battery down to 3.85V per cell which is 15.4V in total. But after discharging, 2 of the 4 cells might end up 3.6V while the other two could be at 4.1V, the end voltage is still 15.4V. This might be an extreme scenario, but you get my point.
Maybe Vifly could re-design this in the future by discharging from the balance connector while monitor all the cell voltages to ensure they all end up 3.85V, that would be much safer. And also it would be nice to bump up the discharging power.