Thanks for the info.
Just for general knowledge, for our Amps/DAPs that use Li-Ion or LiPo, for the purposes of prolonging battery life, what do you guys recommend?
Like avoid fast charging? Charge and top up whenever possible? Or wait till it fully depletes? Don't charge to 100%?
I agree with what
@redguardsoldier said but I'm going to add a few things here an there.
Some quick tech stuff important to my explaination;
Li-Ion: min 2.4V, nominal 3.7V, max 4.2V. Max discharge rate 1~5C (dependent on the construction of the battery, C = capacity)
LiPo: min 3.0V, nominal 3.7V, max 4.2V. Max discharge rate 5~200C (dependent on the construction of the battery, 100C+ only with pulse discharge)
Normal phone, tablet and DAP discharge rate is <0.20C under normal use.
Fast charging
Li-Ion and LiPo can only safely be charged at a max of 1C or 1x capacity. This does in theory mean that you can charge these batteries in 1 hour but in practice this is 1 hour 15 minutes as the last 5~10% has to be done at a significantly slower rate. Fast charging (anything over 10W) can be done without damaging the battery if you keep to this rule. Even if a charger is rated at say 24W this doesn't mean the device will charge at 24W, the device regulates itself and only takes what it needs.
To make this easy when you can and can't fast charge:
1C charge [W] = nominal voltage [V] x battery capacity [A] (mAh/1000)
So a 5000 mAh battery in should be charged with a max of 3.7x(5000/1000)=18.5W. This isn't that much as these days fast chargers are already at 120W.
FYI battery capacity for 1C charge at 10W is (10/3.7)x1000=2703 mAh. If you're below this you should never ever use a fast charger.
Balanced charging is also a thing but this only needs to be done when a battery consists of more than 1 cell. Phones and DAP's only use 1 cell but some tablets and all Laptops use multiple cells either in parallel for more capacity or series for a higher voltage (laptop). This should be handled by the device itself if the batteries are charged internally.
Topping up whenever possible
Can be done in a pinch but should never be done regularly. Always let the battery go down until at least 70% charge before charging again.
Batteries don't like to be topped up all the time.
Fully depleting the battery
Don't do this. This is when the battery gets unstable. Any LiPo should never be discharged under 3.2V per cell and Li-Ion never under 3.0V. I usually set my own safety cut of at 3.5V per cell in RC stuff. In modern phones, tablets and DAP's the 0% battery should be set at >3.3V by the manufacturer but this is not always the case so it's good to never let it deplete past 10~15%. I normally charge when they go under 30% just to be sure.
Charging to 100%
Has to be done every once in a while to keep them in shape but the should be depleted to 90% over the next 24 hours to be safe.
Technically the you can keep a LiPo at 100% for a little over a week without problems or lasting effects but it's advised not to do so.
Storage
Often overlooked but important. Any Li-Ion or LiPo battery that is not used for more than 2 weeks should be given a storage charge. This means the voltage of the cell should be between 3.6V and 3.9V or 45% to 60% charge. With RC batteries this is easy as our charger can do this for us, but with other stuff you've got to do this yourself.
Both Li-Ion and LiPo batteries lose capacity when they are not in use for extended period of time but having them on a storage charge reduces this by 80% for Li-Ion and 90%+ for LiPo. This is at room temperate, high temperatures (40 °C+) will always degrade the battery at a considerable rate.