Efest charger question

[Ace80s]

I have two efest chargers. Both are their entry level chargers. One is a plug to wall, one is a usb. The usb charger is super tiny but it says it can charge 21700. The wall charger is a lot bigger but it says it can not charge 21700. I assumed it must be a voltage thing but I was told thats not the case. I was told if the battery fits in the charger your good to go. The 21700 fits in both but barely in the usb charger but thats the one efest says is for 21700. Was the info I was given correct? If it fits, it will work? Hope I made sense because this doesnt make sense

On a side note, how come no website for efest?

 

[DaveP]

This might provide the info you need.

Chargers Which Fit 20700 & 21700 Cells

21700 battery chargers

 

[Ace80s]

I actually have 21700's but its the same for 20700 and 21700.

This might provide the info you need.

Chargers Which Fit 20700 & 21700 Cells

21700 battery chargers

So it is just the fit of the battery on the charger. Who ever rated the fits on my chargers must have it backwards.

 

[Ace80s]

I was just looking at the charger trying to get the model number and there is a list of batteries it can take. 21700's were listed. The website (18650batterystore.com) listed it as not compatible. I didn't know the site filled in the description. I assumed it was based on info given by the manufacturer. Anyway, they are way wrong.

Back to question 2. No website for efest?

 

[DaveP]

I actually have 21700's but its the same for 20700 and 21700.

So it is just the fit of the battery on the charger. Who ever rated the fits on my chargers must have it backwards.

@https://www.e-cigarette-forum.com/members/ace80s.348913/

The length of both 20700 and 21700 is 70mm.

The first two numbers, 20 or 21 denote the width of the cell in mm. The next two are the length. The last 0 means it's a round (cylindrical) cell.

18650 Battery Review, Test, Specs 2018: 18650 Battery size-dimensions. What do all these numbers really mean? Wild, wild world of Lithium-ion batteries

 

[Ace80s]

Knowledge is power. Thanks

 

[stols001]

Probably because efest (while their chargers are fine) and their batteries less so, are kind of a niche. I don't think there is a board for nitocore either.

I have some 21700 etc batteries where the fit is SNUG indeed. I think just check your user manual OR the back of the charger, my niteccore lists all the batteries it can accept and I was surprised at what it DID charge.

With the snug fit, I have found the technique of pulling the sled as FAR back as it will go, holding it with my finger or fingernail an then using my other hand to gently drop the NEGATIVE side in first, then allowing the battery to sort of slide into the positive side. It saves a fair amount of aggravation for me, and probably saves wraps.

Good luck,

Anna

 

[Ace80s]

Probably because efest (while their chargers are fine) and their batteries less so, are kind of a niche. I don't think there is a board for nitocore either.

I have some 21700 etc batteries where the fit is SNUG indeed. I think just check your user manual OR the back of the charger, my niteccore lists all the batteries it can accept and I was surprised at what it DID charge.

With the snug fit, I have found the technique of pulling the sled as FAR back as it will go, holding it with my finger or fingernail an then using my other hand to gently drop the NEGATIVE side in first, then allowing the battery to sort of slide into the positive side. It saves a fair amount of aggravation for me, and probably saves wraps.

Good luck,

Anna

I learned that with a snug fit charger to hold the battery snug. The battery can shoot across the room farther than you would expect. Thanks for your insite!

 

[Rossum]

I assumed it must be a voltage thing but I was told thats not the case. I was told if the battery fits in the charger your good to go.

There's no voltage difference between the 18650 and the 2x700 cells we vapers use. If it fits, it's good to go. Or at least as good as any Efest product is likely to be.

 

[Hawise]

I was just looking at the charger trying to get the model number and there is a list of batteries it can take. 21700's were listed. The website (18650batterystore.com) listed it as not compatible. I didn't know the site filled in the description. I assumed it was based on info given by the manufacturer. Anyway, they are way wrong.

Back to question 2. No website for efest?

I don't know where the website got its data, but, since Efest doesn't always provide good information, it was probably from someone simply trying to fit the battery into the charger and seeing whether it worked. Even when batteries are nominally the same size (all called 21700, for example) there are actually some variations between models and manufacturers - enough that one 21700 might fit while another doesn't.

Just to make sure things are clear, the 2x700s and 18650s we usually use are the same voltage, which is why you can put a 2x700 in a charger meant for 18650s and it'll be fine as long as it fits. That doesn't mean that a charger can charge any battery that fits. Some batteries have different chemistries (or the same chemistries but different voltages) and need different chargers.

As for question #2, Efest does have a (rudimentary) website, which you can find here: EFEST

 

[Jazzman]

I think the confusion about what chargers can handle 21x700 batteries comes from chargers made a few years ago when 20700 and especially 21700 batteries just weren't common. So if they will fit, even if a bit on the tight side, they will charge fine. But just because they weren't listed when the charger was released doesn't mean you can't use the charger for 2x700 cells. As others have stated, the charging algorithms and voltages are no different so it's just a matter of if they will fit.

An example is my old Nitecore D4 charger. 21700s fit just barely and they charged fine, but they were not listed in the specs that were listed when the charger was new 4 years ago and the specs were never updated once the 2x700 became a thing. But older chargers typically have a much lower charge rate, so charging a 21700 4000 mah cell is going to take a long time. Most newer chargers have significantly increased the available charge rates to reflect higher mah batteries.

But if a cell fits OK, you'll be fine with your charger.

 

[madstabber]

If you do use a charger that barely fits a 20700/21700 be careful of your battery wraps. Keep an eye on them because it they get damaged your battery can short. I used the Liitokala Lii-500 for awhile to charge my 21700’s and it was very tight fit. There’s no danger using a charger like this but I tore some wraps pulling them out. So just keep that in mind and inspect your wraps when you finish charging them and if damaged take them out of rotation until you can rewrap them. Easy process and they are cheap. If you’ve never done it just check YouTube for a tutorial, really an easy process.

 

[Fidola13]

Lots of chargers say they charge certain batteries but don’t seem to actually fit the the the battery cells into their sleds as I found out when trying them in the sleds. Oh well. Both like reading the actually sleds were informational or helpful anyways.

 

[Ace80s]

Thanks for all the advise folks!!

 

[DaveP]

Xtar VC4 is the only charger out of the five I have that fits 2x700 cells without rubbing the end of the wrap.

 

[DaveP]

This guy has an interesting and comprehensive setup for battery testing.

lithium chargers that show internal resistance - Bing video

 

[Doffy]

2*700 are newer cells

if it is not listed, they might just not have been around yet when it was made

but, voltage is the same. If it fits, it fits

 

[DaveP]

Anyone used this charger? It's one of the most capable I've seen.

Adeaska SQ4 Plus Intelligent Battery Charger Review -

 

[Zaryk]

Anyone used this charger? It's one of the most capable I've seen.

Adeaska SQ4 Plus Intelligent Battery Charger Review -

That looks similar to the Opus BT-C3100 v2.2 that I use, but with a little less adjustability and without the internal fan that the Opus has. It does have more info displayed on the screen, with the Opus you have to press a button to cycle through the info.

About the efest chargers, I had 2 of the exact same model chargers from them. One would barely fit a 2x700 and the other would not fit them at all. Since it would be bad for a sales site to state that on the description, it is best to just make a blanket statement that they don't fit that size battery so you don't get a bunch of returns and complaints.

 

[DaveP]

That looks similar to the Opus BT-C3100 v2.2 that I use, but with a little less adjustability and without the internal fan that the Opus has. It does have more info displayed on the screen, with the Opus you have to press a button to cycle through the info.

About the efest chargers, I had 2 of the exact same model chargers from them. One would barely fit a 2x700 and the other would not fit them at all. Since it would be bad for a sales site to state that on the description, it is best to just make a blanket statement that they don't fit that size battery so you don't get a bunch of returns and complaints.

Agree. I've been looking for a charger that does it all. I have several that work fine, but only one (Zanflare C4) displays internal resistance. IR is important because it's an indication of cell age/condition.

Over the years I've bought the Nitecore i4 and i2, Efest LUC V4, Xtar VC4, and the Zanflare C4. Xtar fits 2x700 cells with good clearance. The rest rub the positive end wrap. So far, no nicks, but I can see where the wrap was stressed going in and out. The Efest LUC V4 takes 2x700 cells but getting them out without rubbing the wrap is a pain.

I'd probably jump for the Opus BT-C3100 V2.2 if it would fit 2x700 cells.