A quick introduction to me:
I test software for a living. I have done a fair bit of hardware testing and firmware testing in the past. Some of that was for HP in their SAN (large hard drive storage array) division. I have an electrical engineering degree. I do volunteer testing work for PowerVelocity on the controllers, apps and telemetry modules they sell.
This is the C4012B charger: http://www.chargery.com/C4012B.asp
You can use it as a 50 volt, 1500 watt power supply or as a balance charger for 1S to 12S batteries in any chemistry. It will charge at a max of 40 amps or 1500 watts. The balance ports can be used somewhat independently. Attach a couple of 3S to one port in series and a 2S to the other port and it will charge everything. This is some cool functionality! This all sounds really impressive! As soon as I found out what it's advertised specs were, I wanted one!
This is an early Youtube video of my first impressions of the original beta charger I tried out. I was pretty pleased, but hadn't discovered all its multitudes of issues yet. I think I had used the charger for a few hours when I made this video. Yes that is the real LCD and it's really that lousy.
https://www.youtube.com/watch?v=umoEjxW ... R&index=25
I woke up this morning and the first thought on my mind was that it was time to review these balance chargers. I've sat on my opinions and experiences for about a month now. It's not like what you read next happened last night and I'm still pissed off the next morning. I've been sharing this information with Jason at Chargery since February 2018. A week ago I sent back the 2 chargers I had and got a refund. I'm not mad or angry...just deeply committed to being honest and fair and dealing with others honestly and fairly. I can't apply those principals in any other way to this charger other than to expose it for the flaming pile of garbage that it is.
I want to give reviews that are fair and balanced. I really hate being negative or disparaging. Go read any other review I have posted on ES. This is the first review of a product I've ever done, where my dissatisfaction level is so high that I really question my ability to be nice about it. I have spent hundreds of hours testing these chargers and did not receive payment of any kind for my efforts. I tested them freely, voluntarily and do not expect any reward for my efforts and do not begrudge or regret my efforts. My desire was to help in making a supposedly really awesome charger available to the masses.
NOTE: I was not the only tester involved with this product. I'm deliberately avoiding mentioning other parties except myself and Jason from Chargery. Everything you see below was confirmed by other testers.
My super short review:
I can't in good faith recommend that anyone buy this balance charger. I wouldn't buy one and I've had 3 of them. I'm really disappointed in this charger!!! It is dangerous and can't be trusted. Buy anybody elses charger...they will all be a better product.
A slightly longer review:
You pay $400 for this charger and it's crap. There's places where build quality is terribly poor. It lacks functionality that you get in a $100 charger. It has no app for your phone or the PC. It has a very small, low res LCD that you have to look directly into to read. Typical indoor lighting washes out the LCD. Every other charger with a color LCD is far superior to this one in every way and all of those chargers cost a lot less money. The user interface is clunky. When an operation ends, you can't repeat what you just did by pressing start. You have to wend your way through the menus to find that option again. There's some things...like setup that are hidden. You have to know the secret combination to get to it. The rotary knob interface doesn't always work. One turn/click of the knob ought to be a single increment of an option...nope...not always. Sometimes you just spin and spin and spin and eventually get to the value you want. It does a terrible job at balance charging. Probably the worst issue is that it can damage or destroy your batteries! This IS an expensive balance charger right? It IS supposed to protect whatever battery is plugged into it? NOPE...it can kill your batteries. Seriously!!! I have at least 20 18650 cells that are now flat dead or badly damaged and were working just fine before being "charged" on a C4012B. There's general glitchy things like losing connection with the balance connector while charging. Garbage...just garbage! It is unconscionable IMHO to release a product that is going to harm the very thing it is supposed to protect. Never mind pay $400 for it and it doesn't even work correctly and can be down right dangerous to use.
Do NOT buy this charger!!!
Since February 2018, I have had 3 units in my possession.
The beta unit had issues...no surprises there since it was not a finished product yet. I did a lot of charging and discharging at 6S or less on LIPO and LION packs. I ran that charger at it's maximums for days and days and all it did was get warm and blow a lot of hot air. It seemed to work brilliantly. Then I moved on to 12S. It lasted less than an hour before it shut down for no apparent reason. I pulled the power chord, let it sit a while and plugged it back in. Everything seemed fine so I proceeded to test at 12S again...same thing...shut down in the middle of a charge, but now it wouldn't power up again. OK...time to take it apart and see what happened. I found that a heat sink with a single transistor on it got so hot that it melted the wires that were touching it. This created a short between the balancing board and the transistor and pitted the heat sink. That was the end of the beta version charger. I sent it back with the expectation of what I found receiving some form of correction. In a later version of the charger, I opened it up and found that the "solution" was a piece of kapton tape stuck over the heat sink. Really? Don't fix the over heating problem, just throw a band-aide on it. Well that was disappointing! This was the first hint I had that these chargers are garbage.
The "fix" for the overheating transistor issue...cover it in kapton. Don't bother trying to figure out why the transistor is overheating or use a larger heat sink. Kapton is soooo much cheaper! Ever hear of of "putting a band-aide on the Grand Canyon"? It's applicable!
I wrote this in February of 2018. I wanted to give a fair review that was not premature.
"How do you want me to handle reviewing the 12S balance charger? It's a prototype and it had issues that were probably going to manifest themselves at some point. I don't in honesty think I can do a worthwhile review at this point. I also don't think it would be fair to mention that it had an over heating issue on the prototype that caused it to fail. That would look poorly for the real product."
I soon noticed that they were listed on the Chargery site for sale. I assumed (incorrectly) that all the bugs had been worked out and immediately bought one. Nope...more massively defective chargers that still had lots of major issues to be worked out.
DO NOT sell products that don't work!!! The world does NOT want your dangerous, defective and poorly designed products!!!
This is the first issue I ran into on the production unit. At 6S or less you will probably never see it. At more than 6S, it will crop up randomly and repeatedly. I was told it was due to long balance wires. OK fine, lets make those wires super short. NOPE...still get these errors. Several versions of firmware later and this continued to plague the charger. I tried lots of different battery options...new, old, LIPO, LION (18650, 21700), LTO...NOPE...still happens. I long ago lost count of how many pictures like this one I took and sent to Jason.
Cell 8 was constantly over charging on the second unit. Cell 7 was commonly lagging behind. Keep in mind that the second charger was purchased AFTER they went on sale on the Chargery website! We were reporting this issue in March 2018. It was now May 2018, and these chargers had been on sale for at least a month. IT was mid June 2018 before I got a charger that no longer had the cell 8 issues. How many defective chargers were sold in that time frame? Jason created several firmware revisions to band-aide the cell 7 and cell 8 issues. All the rest of the cells would be charging at 3.8 or 3.9 volts and cell 8 would be ABOVE the programmed limit of 4.1 volts per cell! Cell 7 commonly would be well below the rest of the cells. I reported this problem at least 10 times to Jason with lots of screen shots of the problem.
BTW...over charging any battery will damage or destroy it. It might even explode! Thanks so much for badly balance charging all the rest of the cells in my pack and destroying cell 8!
In these images, you can see that cell 8 is well ahead of the rest of the pack. The yellow bar next to each cell gives a graphical indication of charge current for that cell. Why does cell 8 commonly show MAX current and yet it is always ahead of all the rest of the cells even when exceeding 4.1 volts? How is this in any sense of the word "good"? How did this pass testing by Chargery!?
This pic was taken minutes after starting a balance charge on 12 cells discharged to 3 volts. As you can see cell 8 is rocketing ahead already.
Jason from Chargery eventually sent me a third charger direct from China that supposedly fixed the disconnect issue and the cell 7 and 8 charging issue. Supposedly it had been fully tested by Jason. I received it sometime in mid June 2018. Defective chargers had officially been on sale for at least 2 months by now.
The cell 7/8 issue was mostly fixed, but cell 7 still lags. The connection lost issue was greatly reduced, but NOT cured. I've been parallel charging for many years and no other charger I have ever used had issues with this, but parallel charging on the C4012B would occasionally throw the connection error even after this "fixed" charger. This is 6 sets of 6S in this battery holder. Those 18650s are 100% used cells scrounged from old laptop battery packs. I've been using this battery pack for quite a long time (years) before ever using it as a test pack on the C4012B. I'm charging 3 sets in parallel per 6S port on the C4012B. I got similar results with brand new LIPO packs in parallel. Using this exact set up on my $100 SkyRC D100, charges just fine and has done so for several years now. It is really disappointing that a $400 charger can't keep up with a cheap $100 charger!
I moved on to testing on the third charger (direct from Jason and tested by him) exclusively since it had the disconnect problem far less and it wasn't over charging cell 8. I also simplified my charging set up considerably. I started charging at 12S1P on this 18650 battery holder that has also worked reliably on my SkyRC D100 for several years. In this picture it is populated with used cells, but I have quite a few brand new 18650's as well that I tried. I still got the disconnect errors on this set up....just lots less often.
I even went so far as to make sure I had 12 cells of the same capacity, same Ir and are known good and freshly tested. By this point, I wanted to get good results as often as possible so I was minimizing the possibilities of anything going wrong that I could.
All 3 chargers did a lousy job of balancing the cells in a pack. Do any of these test sets look balanced to you in any way at all? I had balance set to 7mv difference. I have lots of pictures of crappy balancing. You get the point.
Sometimes it would actually do pretty well, but you couldn't count on it.
That brings me to the really egregious issue of damaging or flat out killing batteries. I was using my 12S1P battery holder. I had started a charge, gone to bed, gone off to work the next day and then it was about 24 hours later before I finally got back to looking at the balance charge I started the night before. I was looking at this image on the charger. That's the voltages of 12 18650 cells of which 8 are dead flat or way too low. My DMM confirms that there is no mistakes here. Those are the voltages of those cells. Cell 1, 5, 6, 7, 9 and 11 are all at 0 volts!!! Cell 4 and 12 are WAY below the minimum for LION. This was a balance charge. They should all be sitting at around 4.1 volts right now. WTF?! I repeated this test many times on fresh sets of cells and the charger flat out kills batteries if you leave them connected to the charger! I reported this result to Jason at least 5 times and all I got was excuses why it couldn't be the charger. I was told my batteries were old and defective. I was told my battery holder was defective. I was told that the Ir of the batteries was the cause. Seriously?! Jason told me the internal resistance of the cells was killing them! He specifically said that high Ir will drain out the cells. What nonsense! I can show you the emails. I pulled out my $100 D100 and left 12 cells attached to it for a week. They never drained out or even lost a few millivolts. What garbage! The C4012B charger is 100% defective in this regard.
If you bought one of these POS chargers, do NOT leave batteries attached to it!
In the end I tried pleading with him to remove the charger from the market and to fix them. I was firm but kind. I have filed hundreds of software defect reports. I know how to be professional, factual and detail oriented. I showed the evidence of how they are defective and dangerous. I compared the C4012B to other chargers and to BMS's and how they protect the batteries attached to them, NOT destroy them. I even expressed my concerns in terms of how selling defective chargers would hurt chargery and piss off people that bought the charger. The proof that these chargers are dangerous, badly designed and will destroy your batteries is irrefutable. He only made excuses and claimed "I hurt his feelings". I have followed my conscience and tried to make sure people are not getting BAD chargers. I did due diligence to present the facts and to protect people from harm. Somebody is going to have a battery fire thanks to these chargers or get really mad when their thousands of dollars worth of batteries are damaged or destroyed. I can hear Jason's excuses now...
OK dude...get a clue!