Efest
Efest is a battery accessory brand best known among vapers for its intelligent charging bays. This collection holds 9 Efest products. Every one of them is a charger rather than a cell. The range splits into two families. The compact Slim K series runs from £5.95 for the single bay K1 up to £14.49 for the USB-C powered four bay K4. The larger Lush Q series with its LED status display runs from £14.99 for the two bay Q2 up to £44.99 for the eight bay Q8.
If you run a box mod with removable 18650 or 21700 cells, a standalone charger is not an optional extra. Charging through the mod ties the device up for hours and gives you no visibility of what each cell is actually doing. A dedicated bay charger lets you rotate a charged pair into the mod while the spent pair tops up on the desk.
Slim K series
The Slim K chargers are the pocketable end of the range. The number in the name is the bay count, so the K1 takes one cell, the K2 takes two and the K4 takes four. They use a simple LED indicator per bay rather than a screen, which keeps the footprint small and the price low. The K4 is the USB-C model in the group, so it will run from a modern phone charger or a laptop port without a proprietary brick.
Lush Q series
The Lush Q chargers step up to an LED display and a larger chassis. Again the number is the bay count: Q2 for two cells, Q4 for four and Q8 for eight. The display is the real reason to choose these over the Slim range. Being able to see charge status per bay tells you whether one cell in a married pair is lagging behind the others, which is the earliest warning that the pair needs retiring.
Which cells fit
Efest chargers of this type are built around cylindrical rechargeable lithium ion cells, which covers the sizes vapers actually use: 18650, 20700, 21700 and 26650. The bays are spring loaded so a shorter 18650 and a taller 21700 both seat correctly. Check the individual product page for the exact size list before ordering if you run something unusual.
One point on chemistry. Lithium ion and Ni-MH are different chemistries with different charge profiles and not every charger handles both. If you want to charge AA or AAA Ni-MH cells alongside your vape batteries, confirm that on the product page rather than assuming it.
Battery safety
Removable cells are the part of vaping most likely to go wrong. That is almost always down to handling rather than the cell itself. A few rules are worth following without exception.
Inspect the wrap. Any nick, tear or split in the plastic sleeve around a cell exposes the negative can. Rewrap it or retire it. Never charge or fire a cell with damaged wrap.
Marry your cells. In a dual battery mod, use two cells of the same brand, model and age, bought together and always charged together. Mixing cells makes one work harder than the other.
Carry cells in a case. Loose cells in a pocket with keys or coins can short across the terminals. A plastic battery case costs very little.
Do not leave charging unattended overnight. Charge on a hard non flammable surface where you can see it.
Delivery and support
UK delivery is free on orders over £20 and working day orders are dispatched quickly. If you are unsure which charger suits the cells you run, call the team on 07827 210361 between 8.30am and 4.00pm.
Efest charger questions answered
Does this collection include Efest batteries?
Not at the moment. Every Efest product currently listed here is a charger rather than a cell. The range covers the Slim K1, K2 and K4 alongside the Lush Q2, Q4 and Q8. If you need 18650 or 21700 cells to go with a charger, check the wider batteries and accessories category or call the team to ask what is due in.
How many bays do I actually need?
Match the bay count to the number of cells you run at once, then add a pair. A single battery mod user is well served by a K1 or K2. Anyone running a dual battery mod wants at least two bays so a married pair charges together. Make it four bays if you rotate a spare set. The eight bay Q8 really only makes sense if you own several multi cell mods.
Which battery sizes do Efest chargers take?
Chargers of this type are designed for cylindrical rechargeable lithium ion cells, which covers 18650, 20700, 21700 and 26650 among others. The bays are spring loaded so cells of different lengths seat properly against the contacts. Check the compatibility list on the individual product page before ordering if you run an unusual size or want Ni-MH support.
Why not just charge through the USB port on my mod?
You can on most regulated mods. It does have drawbacks though. The mod is out of action while it charges, the charge current is usually lower so it takes longer and you get no per cell information. A bay charger frees the device up, balances a married pair properly and shows you when one cell is falling behind the other.
How do I know when a battery needs replacing?
Look for three signs. Runtime drops noticeably against how the cell behaved when new. One cell in a pair consistently finishes charging much sooner or later than its partner. The wrap is torn, split or the insulating ring at the positive end is damaged. Any of those means the cell should be retired and recycled rather than kept in rotation.
How should I dispose of old vape batteries?
Never in household waste or general recycling. Lithium cells are a fire risk in bin lorries and at sorting facilities. Take them to a supermarket battery collection point or a council household waste recycling centre that accepts lithium ion. Tape over the terminals before you transport them so they cannot short against anything.