ISDT C4 EVO Smart Battery Charger with Type-C QC3.0 Output for AA AAA Li-ion Battery with IPS Display Screen and Fire Preventionn Material (Black)

IMPORTANT: Please be aware that this review is for the newer C4 EVO model. Most of the reviews found here on Amazon are for the original C4 charger and even some of the reviews for the new C4 EVO have flat out erroneous information. Please read this review in it's entirety as it may clear up some errors I have seen reported by others in reviews here.Let's start with a description of the unique physical layout of the charger. The charger includes 4 vertically arranged bays and 2 horizontally arranged bays. The vertical bays are for use with AA and AAA batteries only. The horizonal bays are for use with Li-Ion and similar chemistries. I won't rehash all the sizes supported, these are clearly listed in the Amazon listing. A couple of notes related to this:Only the vertical or horizontal bays can be used at any given time, they cannot be used simultaneously. So this means that you can service only AA / AAA batteries OR Li-Ion cells, not both at the same time.A maximum of 4 AA batteries or 4 AAA batteries or any combination of up to 4 AA / AAA batteries can be charged at once. Note that this is different from the original C4 could only accommodate a maximum of 2 AAA batteries. The contacts for the AAA batteries in the original C4 were horrible (in my opinion). The C4 EVO has solid fixed point contacts, seperate contacts for the the AA and AAA batteries. Since there are no moving sliders as in many chargers, this should prove to be highly durable.The horizontal bays can accommodate up to 2 Li-Ion cells. There is one review that states that these can accommodate only unprotected 18650 cells. This is flat out wrong for the C4 EVO. It easily accommodates the 18650 protected cells as well as unprotected cells.The same review also incorrectly asserts that there is no analyze or cycle option available. This wrong but I think that there is a very good reason that the reviewer missed this. I admit that it took me a long time to stumble on this because it was not very intuitive. In the menus, you will see an option called "chemistry". By default this is set to "Auto" meaning that the charger will determine by itself if the battery in any given slot is Li-Ion, NiMH, etc. When set to Auto, the only options that you will see are "Charge" and "Destroy". To see the other options (discharge, storage, analyse, cycle, and activate) you need to manually select the chemistry. Once you have done this, all options will be available under "Task" in the menu.Versatile power options: The power input on the C4 EVO is a USB-C connection. Note that no charger is included with the unit - you will need to supply your own. The adapter that you supply will need to support either QuickCharge (QC) 2 or 3 protocols or the Power Delivery (PD) protocol. You can also use the USB port on a computer as a power source. A few important notes regarding this:This charger can charge batteries at a high charge rate (up to 3 amps per cell) / 36 watts maximum for all batteries. If your power adapter is not capable of delivering at least 36 watts at 5V or 9V then the maximum charge rate may be limited to a slower charge rate. If you use a USB port on a computer, make sure that you use a USB 3 port and NOT a USB 2 port. A USB 2 port can only deliver 500mA of current which is only half the 1A minimum needed by the charger. However, the fact that you can even use the USB port on a PC is a really handy feature when on the road with a laptop.Fan: The charger has a cooling fan so be aware that the charger will not run completely silently under all conditions however, I have found the fan to be FAR quieter than the original C4 and it has not bothered me in the least.Hard buttons: The original C4 had a touch sensitive area where there are now physical buttons. Personally, I find the new buttons to be a big improvement as the touch sensitive buttons were more prone to erroneous input.Options galore: Wow - there are a lot of options. You can charge, discharge, analyse, cycle, activate, and place your batteries in storage mode. I'm particularly in love with the storage option. If you are not familiar with this, let me explain: LiIon (and similar) chemistry batteries don't really tolerate long term storage fully charged. As a result, it is best to store these batteries at a lower voltage. As an example, I have a lot of LiIon batteries that I keep only for emergencies to power radios, flashlights, etc. If there are reports of storms or potential emergencies in the next few days I will charge the batteries fully so I'm fully prepared. Otherwise, I will discharge them to a voltage that is healthier for long term storage. This charger can automatically charge or discharge batteries to a level that is best suited for long term storage. Nice feature!Advanced options: For advanced users there are some very advanced options. For example, for LiIon batteries you can set the precise voltage at which charging should be terminated. For NiMH batteries, you can specify the delta V used to determine charge termination. I would strongly suggest not altering these unless you really know what you are doing and have good reason to do so, but the fact that these options are even available are pretty fantastic.USB-C: Just about all my portable electronics use USB-C these days. Having to keep other adapters and cables to support a charger using Micro USB was really annoying. With this charger I am finally free of that and now only need USB-C. This to me is just the icing on the cake of an exceptionally well executed product.Technical Support: I had one or two questions for Technical Support so I set an e-mail to them. I was surprised to get a friendly, through explanation to my query within less than one hour. Very impressive!

Not long ago I purchased the EBL Universal Battery Charger with LCD Touching Screen (https://www.amazon.com/dp/B09B9HFXJ7). I am happy with this charger but I find the slots are not properly configured for the AAA batteries. They just do not seem to sit snug in the slots and I noticed that as I reseat the batteries the internal resistance varies pretty much. Not long after purchasing the EBL charger I noticed the ISDT C4-evo charger. Being the tech junkie that I am I had to get one of these. It took a few months but it finally happened.SIZEAfter unpacking it I put it next to the EBL charger. Holly cow, that is a small charger. See the picture below. The picture doesn't show that the thickness of the C4-evo charger is about half the thickness of the EBL charger. Of course that comes with some limitations to the number of batteries and sizes that the charger handles: the vertical slots can handle up to 4 AA or 4 AAA (or a combination of these) while the biggest battery that can be charged in the horizontal slots is the 18650 (only 2 of them). Also the battery cooling suffers since they are packed closer together. In my opinion the small fan only helps cooling the internal components and has no effect on cooling the batteries.NEW ISDT C4-EVOThe ISDT C4-evo charger is an update from the ISDT C4 charger (which I never used) and it uses physical buttons instead of the touchscreen buttons, has improved battery contacts and it can handle 4 AAA instead of only 2 at a time.FIRMWAREBefore starting any test I updated the firmware to v1.0.0.34. The charger came with v1.0.0.31.Updating the firmware is not mentioned anywhere in the manual. You have to go to the ISDT website (https://www.isdt.co/), change to English language if needed then click on the Support link. There you have to download the ISDT Go software for updating the firmware. You have a choice for MacOS and for Windows. They also show the ISDT App for iOS and for Android but that would not work with the C4-evo charger since the charger does not support a Bluetooth connect. Note that the versions shown for MacOS and for Windows are NOT the firmware versions. You have to install the software, connect the C4-evo charger with a USB cable and then run the software. The software will determine which charger is connected, show the current firmware and then tell you if an updated firmware is available. Installing the firmware takes about a minute.What I would like to see at the website is firmware update notices showing the date they were released and changes introduced with each version.CHARGER OPTIONSThe charger has plenty of configurable options. After powering up the charger, without any batteries inserted, if you long press the center button you get the charger settings. The settings shown with the firmware updated to v1.0.0.34 are different than what is shown in the manual. Some of these settings are straight forward others are obscure (at least to me). The manual describes "Activate Charging" as "If this option is turned on when the user selects the task type as Charging, the charger will automatically discharge the battery before charging. This is to eliminate the memory effect of the battery and restore the storage capacity of the battery.". Don't know about others but this makes me scratch my head. To make things even more confusing firmware v1.0.0.34 has a setting named "Activation Charge". To me that has more to do with the battery activation, but Battery Activation is an operating mode selectable per battery once inserted. As I said... Confusing!The included simplistic manual does not help at all. For example what is the "Destroy" mode of operation? I can't really help it but chuckle when I associate this mode with the charger model C4. Or What is "Capacity limit"? The manual says: "Set the maximum battery capacity".OPERATION MODESThe operations you can perform on batteries are Charge, Discharge, Storage, Destroy, Cycle, Activate, Analyze.The Charge and Discharge modes are straight forward.Storage will discharge a battery to a certain level for long term storage. This applies to Lithium type batteries which do not quite like being stored with a full charge.Destroy... hmmmmm... well... OK...Cycle will let you repeat Charge or Discharge a number of times.Activate will attempt to revive a battery that was discharged so deep that it can no longer be charged normally.Analyze will perform a Charge followed by a Discharge followed by a Charge. This is supposed to give you the state of health of a battery, showing its capacity recorded during the Discharge step. The Charge/Discharge current is shown for example as 0/-0.5. This means that the battery is discharging at a rate or 0.5A. On the same hand the Capacity is shown for example as 231/-2345 mAh. This means that at that particular moment in time the battery received a charge of 231 mAh and put out 2345 mAh. At the end of the Analyze operation the number on the right would indicate the real battery capacity.In Analyze mode the charging and discharging current is set to 1A. Cannot be adjusted. If I adjust in Charge and Discharge to 0.5A then I go back to Analyze it will be 1A. That is WAY too high for AAA batteries. They will get VERY hot. For AAA batteries instead of Analyze I would have to do separate Charge and Discharge operations so I can set the current. This is not very convenient because you have to be there at the end of the Charge and Discharge modes to start the next step.When an option is set to AUTO other related options are not available. This may lead people to believe that those options are not supported. I recommend to change the options set to AUTO to some other setting and then explore the other related options. However, when changing options make sure you understand what those options do.While running my first test in Analyze mode with AAA batteries, 3 batteries just finished the analyze operation and one was still charging. Their temperatures were between 40 and 43°C. The 3 that just finished charging felt lukewarm to the back of my fingers. The 4th battery that was still charging (showing 40°C) I felt a little burning sensation. Its temperature had to be much higher. I do not consider the temperature readings accurate.ISDT SUPPORTUnfortunately this is one area that brings down my rating the most. So far I have attempted to contact ISDT 4 times: twice thru Amazon messaging and twice thru direct email to hi@isdt.co. So far I received no response. I call their support abysmal and I cannot count on it in the future.FINAL REMARKSYes... the charger works, at least for now. However it can easily damage AAA batteries. It has obscure and/or confusing options and settings which due to lack of response to my attempts to contact ISDT I cannot clear out. I asked in Q&A about charging the newer AA Lithium 1.5 Volt Rechargeable Batteries with the hope that I will receive an answer. Instead what I got was:- Yes two ways turtle or rabbit.- Yes, you can. The holder is flexible.Apparently ISDT used the listing for the older C4 charger when they introduced the new C4-evo charger. As a result Q&A and reviews can and will refer to both models making things even more confusing.So the question I have to answer myself is: Do I need this headache? I know that the C4-evo charger looks nice, is small, feels good in hand but is that worth it? Couple that with the complete lack of support from ISDT. I think the answer to that question is a resounding NO!