Youshiko YC4000 (official uk 2026 version) intelligent aa aaa professional standard battery charger with 1000mA charge current + usb port

I have bought many chargers in past like Maha, Technoline, AccuPower, Energizer etc as I charge batteries every other day, I rely on them heavily for my work.But I must say, this New UK Model Youshiko YC4000 to be overall better intelligent battery charger and value of money, probably best intelligent battery charger I ever bought.I have learnt from my own experience with one of my old charger ( Don’t like to name the brand ), lose connections may not charge at all or charge slow or some time make you charge again, total waste of time.But in Youshiko YC4000, inserting the batteries in charger, Gently need to tuck in the negative end under a lip in first and then push the positive end down and when taking the batteries out , Gently you need to push back from the positive end towards negative end and then pull out the batteries. Which I think it’s a clever and neat design, as batteries connections in each slot with charger are very secure. As it should, secure connection to achieve accurate charging.Youshiko YC4000 refresh function is 100% better than other chargers; I have charged nearly 3 years old batteries which my other chargers refused to charge. I have already saved money and I am sure, I will save more in coming days and weeks, as I have more old batteries.I have used this charger for around or over 30 hours constantly with no problems at all.I have used Charge /Discharge / Refresh function, I have not used the test function yet. I have charged my phone with the USB Port, All functions works very well.It does exactly, what it says in the description of the product.Power Supply is a UK Plug but it is 110v to 240v, so this can be use worldwide with a simple travel adapter. Also there is option to buy car adapter but not included.This YC4000 is very similar to Technoline BC700 ( with max 700mA ) but this Youshiko YC4000 have more powerful charge with 1000mA and offers more options, like USB output and car adapter option on much cheaper price than other brand chargers.It is Professional standard, high quality, you will get more for your money, highly recommended.I emailed Youshiko (email address found in instruction book) and asked for a PDF file of the instruction book so I can have it in large print and I received it, with in 2 hours, Instruction book found to be quiet good.Very good customer services.I must say again, probably one of the best intelligent battery charger, I ever bought .

Just great. This is an almost identical but improved version of the well regarded Technoline BL/BC-700 (or Lacrosse BC900) - improved by the addition of an extra 1000ma charge setting for very fast charging and a 5V/1A usb output for phone/tablet charging. Note that it is not recommended to do fast charging often as it apparently reduces the life of the battery, the charger defaults to the minimum 200ma charge rate,which is very safe, you can also select 500ma and 700ma (the corresponding discharge rates are always half of the charge rate.This is one of the best chargers you can buy, see these two youtube reviews (of the virtually identical BC700) to see why it might be a better choice than an even more sophisticated model.https://www.youtube.com/watch?v=C3SBjrhANSshttps://www.youtube.com/watch?v=JslHWoXpnEwBe warned that it is not a simple device, and the instruction manual is very concise, but once you get used to the controls it is brilliant. You can select individual batteries at any time and change the charge/discharge current or mode (charge, discharge, refresh or test) - to do this you press 1,2,3 or 4 to select a battery and then you MUST press the mode button, even if you are just changing the current (in which case you have to cycle through the modes to get back to the original mode - a little design fault there). Alternatively you can remove the individual battery and reinsert - then you have 8 seconds to select the new current/mode.It displays, for each battery individually, charge/discharge rate (in mA), the battery voltage (which should be 1.4v - 1.5v for a fully charged battery), amount of power (in mAh) charged or discharged in the current cycle (this resets to 0 mAh if you change mode or current) - and the time each battery has been charging/discharging in the current cycle (which resets to 0:00 (h:mm) if you change the mode or current). You can even change the display setting individually for each battery.Test mode is genius, it first fully charges the battery, then completely discharges to measure the capacity, and finally fully recharges again! The final display shows the voltage of each battery, the measured capacity during the discharge AND the time taken for the full discharge (this was confusing at first as I thought it would show the time taken for the last charge cycle) - which is great info - you can put the batteries in at night time, set to test mode with 500mA current, and the next day you have fully charged batteries and precise info on their capacity. Note that the capacity will display "---" until the full discharge cycle completes, and if the capacity is greater than 1999mAh the display switches to Ah units (eg 2.50Ah = 2500mAh). Refresh mode repeats this discharge/recharge cycle until no improvement is detected in the discharge capacity (up to a maximum of 20 cycles) - beware that this can take several days for large capacity batteries on a low current charge.Some small cons1. It failed to detect that one battery was fully charged and started to overheat - it stops charging once temperature gets to 55ºC - but it's a little bit annoying to see a battery stuck at 1.46v for over an hour (it should switch to trickle charge once full). This may be a dud battery, it's an old high capacity 2700mAh one that now only holds half that charge.2. Batteries are almost (but not quite) touching, so some heat does pass to neighbouring batteries.3. There is no simple discharge cycle - the mode named discharge - does discharge the battery but then fully charges it (to remove memory effect in NiCD batteries) - you have to keep an eye on the LCD display and remove the battery if you want to store it discharged (even the test mode, which fully charges and discharges to test the capacity, does a final full charge cycle)4. No backlight on the lcd screen so cannot adjust settings in a dark room (UPDATE: you can plug a usb light in the usb port!)5. No cover or case to keep dust out of the charger.But, these are minor issues - the individual voltage and current measurements and settings are great for a device at this price. At first I was a bit worried because it looked a bit cheap and was confusing to use - but after playing with it for a few days and charging a few sets of batteries I'm really happy - my simple uniross fast charger was really not fully charging my batteries - now I have full controlNB as an above reviewer wrote, insert the batteries properly - push back on the negative contact and then push down the postive end of the battery to fit it firmly in the slot.edit: One more plus point - uses a standard 12v power connector, so can be operated from solar power easily (if that's an option)edit: you can use the superior manual for the Lacrosse bc700, which is a bit easier to read, also tells you that when the capacity exceeds 1999mAh the display changes to Ah, so that 2500mAh will read as 2.50 Ah on the display.http://www.lacrossetechnology.com/bc700/manual.pdf[UPDATE 8/4/2015: The charger is working well and I am very happy but just want to mention that on the lowest current setting of 200mA it sometimes fails to detect a delta-V drop in voltage at full charge and stop charging. I have only noticed this with uniross hybrios and only at 200mA, it may be a characteristic of that particular battery model. It happens less than 10% of the time and I mostly use the 500ma current in any case, so it's not a big issue for me. EDIT 23/4/2015: Apparently I just to need to be patient and wait a lttle longer, about one and a half times the rated charge may need to be supplied sometimes - it DOES eventually reach full charge - my mistake]

I purchased this unit as a replacement for my failed BL700. That one never worked properly with regard to the buttons but thankfully this charger by Youshiko has worked flawlessly so far.It has all the functions of the BL700 and although it has slight differences regarding the styling and feel of the buttons it works just as well.You can discharge, test and exercise the batteries as well as charge them of course and all independently in their own channels. You can charge AA in one channel and a AAA in the next of course.You can discharge another whilst also charging the next.All combinations are supported.I have already gone through my entire stock of 20+ batteries and given this unit a thorough test and I am happy to report no weird issues or bugs.All batteries were charged up without a fuss. You can really ramp up the charging current but this can heat up the batteries somewhat. I used a cooling fan to aid bringing the temps down when charging at the full 1000 mA rate.I did read a review where someone had tested this unit for high over temp cut off and it didn't work but I have not replicated this due to not wanting to cook my batteries. They did get very hot so I would not want to leave this unattended for any length of time without checking how hot each cell gets.Other than that, I have noticed a small mark on the LCD which is a shame. The mark is under the plastic display on the actual LCD panel so would have been damaged during manufacture. It loses a star for this.Thankfully everything else works ok and overall I do like the unit for charging and conditioning my batteries.

Compact complete with a dedicated external power adapter.Contents were the charger , power adapter and user manual.The user manual is a miniature version with print so small that is barely legible so I first had to scan and copy the pages to enlarge from 100x150mm (open book size) to A4 to give myself an A5 booklet that could be read! That is a zoom of 195%The website for Youshiko is not in the manual but I found it at www.youshiko.co.uk. It has been under construction for over a year with no supporting manual downloads. So if you have any problems it does not inspire confidence that the company will be able to help you. Don't lose your manual!Take care inserting the battery. You need to tuck the negative end under a lip first, then you can push the positive end down into place. With the battery's so close to each other, removal of the middle two (when four in place) is difficult. So although you have independent controls for each battery physical access is limitedClaimed to charge each cell independently, that does seem to be the case. I inserted two nearly full and good AA rechargeable batteries and set it to discharge. After just over an hour draining at 100ma I inserted an additional pair of old rechargeable batteries and while discharging the other two still it set about recharging the old batteries at default settings. On initially inserting a new battery(s) you have eight seconds to alter the setting for it before it starts at default settings. So it would seem you could insert each battery and have it doing one of the four functions - Charge, Discharge, Refresh or Test. Each one at custom rates if you want to.There is a further facility to charge USB devices as it has a USB socket for you to plug your specific USB lead into. Note this is purely for charging and not supported with any LCD display or data exchange. - I have not tested it yet.I found the manual to be good once I had it at a size I could read.Overall this is very similar to the Technoline BL-700 but with the added support of a USB charging port.Very useful for reviving older batteries into better condition. Dispalys of voltage etc. will allow you to identify the old duff ones!I will update after some more use. - At the present time I really like the functions it offers. Reliability is as yet unknown.UPDATEI have now been using mine almost constantly for three weeks and have to say I am very pleased with it. It has allowed me to sort out various bad rechargeable batteries that you can't identify with more basic chargers. The individual battery settings mean that you can mix in AA and AAA sizes as well during charging so it performs as if 4 individual cell chargers! I have also used the USB output to charge my wireless keyboard and this simple addition over the competition was why I chose to get this charger - It has turned out to be the right decision. I have been able to recover some old batteries by setting the charger to fully discharge and then re-charge them. Then using the test setting to find out what the capacity of the battery is - The test is essentially a measured output from fully charged to fully discharged and the battery is then fully recharged after the test.I requested from Youshiko and was sent a ".pdf" file of the manual which allowed me to print a full size A4 copy for easy reading without my glass's or magnifying lens. If they get around to putting it on their website it will be even better. So pleased that the company offers a degree of service.

I bought this charger as a replacement/upgrade for my Vanson Speedy Box which has given excellent service for over 20 years.I have to say, the YC4000 is much better. Admittedly it won't charge anything larger than AA (unlike the Vanson which went up to D cells), but I can't remember when I charged anything other than AA or AAA. The YC4000 manages these (AA & AAA) very well. It may not be the cheapest AA charger, but in my view it is well worth the extra, and extremely good value for money.Already the YC4000 has rescued two NiMH batteries that I thought were beyond hope. The 'Refresh' mode (which is designed to rejuvenate old rechargeable batteries) can take a long time (days) to complete its task, but the good news is that if the battery is completely hopeless, it will tell you very quickly.The LCD digital display is helpful, and easy to use, and the overall size makes the YC4000 very portable. I also like the 12v input socket on the charger (which conveniently is the same voltage and polarity as the Vanson) because it allows me to use the YC4000 in my car while out and about.The 'Test' mode is also a very clever idea; it provides an accurate indication of the capacity of a rechargeable battery.One important consideration for me was that the YC4000 allows me to charge batteries individually. That, I can charge 1, 2, 3 or 4 batteries at a time. Many of the other (cheaper) battery chargers available only charge batteries in pairs. Not only would I find this inconvenient, but I don't think it can possibly be as good for the batteries as charging (and monitoring them) individually. This is even more important when charging batteries that have not been used in pairs, since they will be in different states of discharge.

Bought this to replace a (significantly more expensive) old charger, which seemed to be over-charging cells. The YC4000 has been great in really letting me understand the state of the various cells I had lying around. Have tested this over the past couple of weeks and I'm reporting my findings here.First off were a bunch of old NiCd AA and AAA's. Through years of abuse and neglect, these had discharged completely for a long period of time. This charger indicated they were duds. Even if I could have refreshed them to half of their original capacity using the widely-published "paperclip trick", who wants a 500mAh AA these days? Binned them.Next were some Uniross Hybrio AAs (Eneloop equivalents). Originally, all eight of them were reported by this charger as having a capacity of 1400-1500mAh. Put them all on a full refresh cycle over the next few days and I've now got a great set, with capacities from 1950mAh to 2050mAh (rated at 2100mAh). Other fast chargers would have just continued to toast them before they became completely worthless.Final test was for a pair of AAA NiMH. The refresh cycle completed successfully, although it did claim a final capacity of 650mAh for a product labelled as 550mAh. Will try again in the future and see what happens after a few more discharge-charge cycles.Operation? Well the user manual looks a little complicated, having multiple modes and display settings, but really it isn't. Just shove the cells into the charger and provided you've got them the right way around then this compact unit will happily recharge them, albeit a little slowly. Want to charge a little faster? Provided you do it within 8 seconds (which is easier than it sounds), then just press the Current button. Easy.Exploring more of the functions, I've had a play with all of the modes."Charge" is a bog-standard traditional charger approach - top up whatever capacity the cell has right now until it is full."Discharge" is a bit slower, but kinder to the cells by completely discharging and then charging from empty, thus avoiding the "memory effect"."Test" is slower again, having to fully charge the cell before doing exactly the same as the "Discharge" cycle. This one is to see exactly how much capacity you really have available to you."Refresh" is even slower still, but does the best job it can of restoring your cells back to full operation (see above) by continually cycling through a discharge-charge loop until the measured capacity does not increase further. As I found out in my first test, if you select a charge current of 200mA and have 2100mAh cells, then this can take days to complete.Other things: while the display looks a little primitive, it actually tells you everything you need to know. Getting the cells out after charging can be a little fiddly (especially from the middle slots with cells either side) but isn't worth losing sleep over. I don't know exactly how heavy I was expecting the unit to be, but it's very light - possibly feeling a little too light and flimsy on first inspection, but it doesn't seem to flex at all, so I guess it's well-built, but just not very heavy.In summary - a great product that does the job nicely. If you have 8-10 old rechargeables lying around, the extra cost of buying one of these over a cheap charger will probably pay for itself by refreshing the cells you already have back into life. Recommended.

A fantastic purchase! Completely satisfied!

A downgrade. It claims to be the new version but the screen, charge circuit etc is cheaper and nowhere near as good as the original version when opened up with poor quality soldering etc.These are known to be one of the best pro manual chargers for AA and AAA Eneloops in particular if you care about a proper subtle charge that’ll get them to 100% with the least amount of stress and a leave and forget feature set.Two of my brand new eneloops were destroyed by over charging. The first digit on lane 1 when showing 4 numbers is hard to see and its count meant even though my 2000mah Eneloops were being charged as if they had 2700+ it continued and clearly overheating occurred before removal. There’s a platform of these and I’d get the one up. The 5000 series don’t have this issue as this was a second one that failed and ruined batteries by failing to detect the correct voltage. It’s silent, lots of charge options as on par with the 5000 series but I wouldn’t leave batteries charged unattended in this thing. It’s a safety issue. Perhaps I got two duds in a row. Best to test at different amperage.I recommend getting the step up to this model instead. Sadly the new revision has been gutted and build quality isn’t as good as it used to be.Shame.

Pour charger des batteries au Royaume Uni, ce doit être parfait car l'unique chargeur est à la norme britannique. Mais pour la France et la Belgique c'est impossible car il n'y a pas d'adaptateur de prise prévu.