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Xtar - D4 4-Slot Quick Charger


Gold Contributor
Member For 4 Years
Hi Vaping Underground members, In this review i take a look at the D4 charger from Xtar. The D4 charger was supplied for the purpose of this review by Herman from Xtar.


The D4 is a 4 slot quick charger and is one of the AC range of chargers. It is an uncomplicated 4 slot charger from Xtar with LED strip progress indication (Xtar refer to it as Owl-Like UI Design). Supporting 2A charging for up to 2 slots and i found that using all 4 slots was charging at 1A speed, it certainly improved my own personal experience of charging my batteries. If you are well up on your technology this review might not be for you as it's a simple how a vaper who needs to constantly charge batteries found this product and nothing else. I don't have equipment to give data and charts but did consider including data i found on the internet but as i would be giving technical information that wasn't my own and don't fully understand i decided to not do that and only include some terminating Voltage's after charging so this is not a review full of Science just i did A and experienced B.


In the Box


D4 Charger
Power Cord


Opening the Box

The D4 comes professionally packaged with outer cardboard box and strong inner plastic holder which feeds through the top of the box to allow for hanging for retail display purposes. The charger arrived in excellent condition and is a strong sturdily made product no complaints at this point whatsoever. The Specs and Features of the device are written on the back of the box but also included is a manual written in eleven different languages but doesn't give any further information about the charger other than what's already given on the box other than cautions and the obvious, telling you to put batteries in the slots and plugging the charger in. After saying that i suppose other than getting very technical which will go over most peoples heads (and that's not a criticism i include myself in the most people) there's not a lot more needed from the manual.


D4 Specs and Features:

Size: 130 x 118 x 36mm
Input: 100-240V~50/60Hz 0.8A
Constant Current: 2A x 2/1A x 4/ 0.5A x 2(CH2&CH3) +1A x 2
Cut-off Voltage: 4.15-4.25V
Operating Temperature: 0-40℃
Quick and intelligent charger
Simple and convenient operation
Two-slot 2A Fast Charging
Unique Owl-Like UI Design
Battery Life Optimization Charging
Various charging protections
0V Activation Function Revives Over-discharged Batteries
Battery Life Optimization Charging
TC-CC-CV Three-Stage Charging
Elaborate Heat Dissipation Design
4 battery slots
Compatible batteries:
3.6V/3.7V rechargeable Li-ion / IMR/ INR/ ICR 14500 14650 16340 17335 17500 17650 18350 18500 18650 18700 20700 21700 22650 26650 Li-ion batteries


My Only Comparison

Obviously how i found the charger had a lot to do with what i have experienced from my previous charger. I have been using the Nitecore i2 intellicharger for the last 2 years and i am talking about the original that only charges at 0.5A, has 2 slots, 3 small LED indicators per slot and 2x700 batteries would not fit. For 2X700 batteries i have been charging in a device i don't use for vaping at 1A which i only use for that purpose and only charge while i am around to keep an eye on it.
That's the background to my previous charging method but although their was a big room for improvement this is about the Xtar D4 and i am not knocking the i2 not after 2 years continuous use without ever letting me down and still works as well now as it did when i first bought it, a real trooper!


Some Main Features

0V Activation Function
Current Buffering Technology
Heat Dissipation Design
Battery Charging Optimization Charging


Charging Indication

Each battery slot has 4 LED strips above it that shows charging progression, the LED lights a very aesthetically pleasing shade of blue (objective of course). The indicator strips only activate above the slots which contain a battery and start by the strips lighting in order then they go off and keep repeating this cycle so 1 lit, 2 lit, 3 lit, 4 lit then all off. After a while of charging 1 strip lights solid while the other 3 lights follow the sequence as described previously. Again after a longer period of charging 2 strips light solid, followed after a while more 3 strips light solid then finally when the battery is fully charged all 4 lights are permanently on. The charger uses a buffer and when you switch the charger off any lights that are lit remain on for 15 seconds after cutting power to the charger.

I found 3 batteries took the same time to charge as 4 batteries.


Review Continued Below:


Gold Contributor
Member For 4 Years
Review Continued:

My Experience Using The D4

I received the D4 early in December and have been using it since which is a good amount of use as i am mainly a DL vaper, i also test devices constantly for review and my wife also uses external batteries so as you can imagine it takes next to no time before i have batteries that need charging. I decided to concentrate on using the device 2 main ways for the purpose of this review, i charged using all 4 slots and also charged batteries individually just using one slot. I did charge 3 batteries but only on the one occasion. The batteries i mainly charged were VTC5A's and found charging one individually took between 1hour 10 minutes and 1hour 20minutes, the variation is down to two things only on one occasion i timed it accurately and also i guess the age of the battery as i found termination voltage (the only thing i found a way of testing) was lower the older the battery was. I'm not that technical as i have stated but it seems this variation in termination voltage is a good thing as it's charging the batteries safely dependant on the state of the battery smartly rather than trying to force 4.2v. When using the charger with all 4 slots i found 4 VTC5A's took barely over 2hours which impressed me, on occasions in the fourth slot i charged a 30Q 18650, a 20700 battery or sometimes a 21700 battery (occasionally used slot 3 and 4 with different batteries but had the same results). After the 3 VTC5A's charged still in barely over the 2 hours both the 30Q and the 20700 took a further 15 minutes (approx) while when the fourth battery was a 21700 battery a further 35 minutes (approx) was needed. I found this part of the specs confusing "2A x 2/1A x 4/ 0.5A x 2(CH2&CH3) +1A x 2" as the "1A x 4" contradicts the "0.5A x 2(CH2&CH3) +1A x 2" it seems to be saying in one part of the specs using all 4 slots gives 1A charging in all 4 slots while the next part of the specs seem to say 1A charging for the outer slots but only 0.5A for the middle slots when using 4 slots, after countless charges using all 4 slots giving the charging times i have quoted it's clear that it was charging all 4 batteries at 1A. Finally what i wan't to point out in this section is at no time did any battery or the charger get hot.


Single VTC5A 18650 Indication Timed

It bored me to tears but luckily with how quick the D4 charges a battery the torment was over in 1 hour 16 minutes of continually watching the indication lights. After 12 minutes the first LED strip lit solid, after 25 minutes the second LED strip lit solid, after 48 minutes the third LED strip lit solid and finally after 1 hour and 16 minutes the fourth indication strip lit solid and the battery was fully charged. Testing the termination voltage of the battery after charging showed it to be at 4.11v.

Termination Voltage Results

I did randomly test the termination voltage after a charge, the results were:


There was a trend between voltage and the age (past usage) of the battery.


Battery Charger Safety Protections

When a battery is inserted into a slot and all 4 indication lights blink simultaneously then a protection like Short circuit or reverse polarity has kicked in. The D4 has an impressive array of safety protections.


Short Circuit Protection
Over Heat Protection
Over Current Protection
Over Charge Protection
Anti Reverse Protection

The D4 has temperature monitoring and heat dissipation design, it also is made of flame retardant material and has a 1 year Warranty.


Final Thoughts

I am more than happy with the D4 charger and how it performs for me. Previously one or two VTC5A batteries would take over 4 hours to charge while a 30Q would take around five hours. I was limited to only being able to charge up to 2 batteries at a time and 2X700 batteries did not fit my previous charger. Now a single VTC5A 18650 takes not much over an hour to charge, using all 4 slots i can get 4 batteries charged in barely over 2 hours and now i can also charge my 2x700 in the charger rather than using a separate device. The progress indication i find very adequate and batteries and charger stays cool at all times.

I would once again like to thank Herman from Xtar for supplying the D4 Charger for the purpose of this review.


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