Since 'Battery University' has not yet been linked to, on this thread, here's the link to the
BU-409: Charging Lithium-ion lesson.
The bottom lines are:
Simple Guidelines for Charging Lithium-based Batteries
- Turn off the device or disconnect the load on charge to allow the current to drop unhindered during saturation. A parasitic load confuses the charger.
- Charge at a moderate temperature. Do not charge at freezing temperature.
- Lithium-ion does not need to be fully charged; a partial charge is better.
- Not all chargers apply a full topping charge and the battery may not be fully charged when the “ready” signal appears; a 100 percent charge on a fuel gauge may be a lie.
- Discontinue using charger and/or battery if the battery gets excessively warm.
- Apply some charge to an empty battery before storing (40–50 percent SoC is ideal). (See BU-702: How to Store Batteries.)
You can't easily measure the current charge state or the current maximum, can you? So how do you follow that general advice [to store at] 2/3s of theoretical?
Personally, I know how long my light will last on its battery pack, so I charge it up and then put the load (the light) on for 1/3 of the normal length I get with the headlight on my bike.
[QUOTE 5031729, member: 9609"] Q1: Do these batteries suffer from memory type issues or is it OK just to pop them on the charger and bring them back up to full charge after just a short use ?
Q2: When it says a battery is good for 300 recharges does that mean 300 recharges from being completely flat, and would that be equivalent to 600 charges from half flat ?[/QUOTE]
A1: "Li-ion is a low-maintenance battery, an advantage that most other chemistries cannot claim. The battery has no memory and does not need exercising (deliberate full discharge) to keep it in good shape. Self-discharge is less than half that of nickel-based systems"
Source
non-A2: What is the (second word) "it" which says 'good for 300 recharges'? I think the best advice is to follow good charging procedures (in particular don't recharge with any load on the battery) - see my first link. These sort of claims on item description/specification material for general public purchase are very difficult to verify or contradict as there are so many variables. (Off topic) At least one (with the resources) could test the claimed 3000 lumens (Ha! Ha!) for a Chinese headlight and 100,000 hours life (light powered by 2 x CR2032 button batteries).