How to Choose the Right 18650 Battery
An 18650 is a lithium-ion rechargeable cell measuring roughly 18 mm wide and 65 mm long. The same size fits torches, vape mods, power tools, e-bikes, laptops and DIY battery packs – but the cells inside are not all equal. This guide covers the four things that actually matter when you buy an 18650 in Australia.
1. Capacity (mAh) – how long it runs
Capacity is measured in milliamp-hours (mAh). A higher number means longer runtime. Genuine 18650 cells range from about 2000 mAh to 3500 mAh. Be sceptical of cells advertised as 5000 mAh or 9900 mAh in an 18650 size – that capacity is not physically possible and is a sign of a fake.
2. Discharge rating (A / CDR) – how hard it can push
The continuous discharge rating (CDR), measured in amps (A), tells you how much current a cell can safely deliver. High-drain devices – vape mods, RC, power tools – need high-drain cells (20A–30A) such as the Sony VTC series or Samsung 25R/30Q. Low-drain devices such as torches and power banks are fine with standard cells. Using a low-drain cell in a high-drain device is dangerous.
3. Protected vs unprotected
Protected cells have a small circuit board that guards against over-charge, over-discharge and short circuits – ideal for single-cell torches and general use. Unprotected cells are shorter and higher-drain, and are used in devices or packs that manage protection themselves (vape mods, tool packs). If you are unsure, choose protected.
4. Flat top vs button (nipple) top
A flat top has a level positive end; a button top has a small raised nub. Some devices only make contact with a button top, while series battery holders often need flat tops. Check what your device requires before ordering.
5. Buy genuine cells from a real supplier
The 18650 market is full of re-wrapped and fake cells. Buy from a supplier that lists the true brand, capacity and discharge rating – and that you can actually contact. At 18650.com.au we stock genuine Sony, Samsung, Panasonic, LG and other cells, ship Australia-wide, and offer local pickup in Heidelberg West, Melbourne.
Need a hand matching cells to your device? Call us on 03 9459 7206 or email sales@lanplus.com.au.