Can anyone recommend a good mid priced Li-ion battery charger? - Page 1
Forum section: electronics / general

author: tron9000
author_rank: Frequent Contributor
timestamp: October 13, 2015, 07:27:51 pm
content: By mid priced I mean £20-£40, or am I deluded at thinking that's mid ranged? If so what's a good price for a decent one?Basically I have a load of Li-ion batteries (18650) to charge and my current one only has 2 bays and measured the charge rate a 100mA. I'm not sure on the capacity of the batteries I'm charging, as they have been harvested from laptop battery packs, and some don't have part numbers, but I'm giving an educated guess of 1000mAh or there abouts.Also I am suspicious about how well designed it is as I don't think it trickle charges once it reaches the right voltage, I think its just constant current all teh time. I got it with a head torch I bought:As such I'm paranoid about them over charging and burning down something! To be honest I wouldn't trust this thing as far as I could throw it!So I'm looking for something that's within my price range and that anyone can recommend.Many thanks

author: rsjsouza
author_rank: Super Contributor
timestamp: October 13, 2015, 07:36:23 pm
content: I have a Nitecore Intellicharger i2 (two batteries), but there is afour battery version.Mine is well built (check here) and does a pretty decent job at fast charging. It does not have fancy LCDs, but it has independent channels, it does trickle charging and has the mains power supply integrated into the unit (better portability).

author: deadlylover
author_rank: Frequent Contributor
timestamp: October 13, 2015, 10:46:44 pm
content: I have a XTAR VP1 and I'm pretty chuffed with it, uses proper CC/CV unlike the cheapies and you can select 250/500/1000 mA charge rate. It also reads out the voltage of the batteries, very handy.I'd probably go for the VP2 as it's newer with a few more features, only a few dollars more IIRC.I wish it could go higher than 1000mA for quicker charging of 3400mAh 18650's but oh well, can't have it all. You can find a reviewhere.

author: SteveLy
author_rank: Regular Contributor
timestamp: October 14, 2015, 02:48:26 am
content: Another vote for the nitecore i4/i2. Bang for buck, no frills, just works. Unless you need faster than 0.75A.If you're going to use it on AAAs, be sure to read the instructions (they must be paired in i4 bays 1&3, 2&4 to limit current to 375mA).

author: djQUAN
author_rank: Frequent Contributor
timestamp: October 14, 2015, 03:28:02 am
content: Also an i4 user here. I did a teardown of both the i2 and i4 back then when I first got one.http://www.quan-diy.com/misc/nitecore/i4.htmBut my i4 blew its AC side shortly after but it was too much a hassle to fix so I used it on 12V DC then on from my renewable system at home.

author: tron9000
author_rank: Frequent Contributor
timestamp: October 14, 2015, 09:56:04 am
content: Thanks, much appreciated people, like the teardowns! Gives you a better idea of the quality your getting

author: Lotus
author_rank: Contributor
timestamp: November 10, 2015, 12:05:25 am
content: HelloI have the i4 charger and when I charge 4 x 18650's at the same time, it takes forever, something like 24 hours or more.But then again the charger says it's a 10 W charger, so there is not a lot of power to go around.Does any of you guys know if this is the downside of the 18650 - long charge time?I have LiPo's, and they carge very fast, even my dewalt drill charge in like 20 min.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 12:19:19 am
content: QuoteLi ion chargers don't do constant current or trickle charges. They do current and voltage limited charging, such as you would get from a lab power supply. There's really no "switching" technically speaking. Although this is usually how it is described, that description is somewhat misleading. It's just that once the charge voltage at the battery terminals reaches 4.2V at X max current, there is no longer any need for current limiting, so that part is "done." The current will thereafter be described by the ESR of the battery and ohms law, which means it will decrease from that point on, until it's just a trickle. All by itself.If your chargers provided a constant 100mA without voltage limiting, they would completely kill your batteries the first time you left them in too long. It would be easy to tell. Hook a DMM up to the contacts while a battery is in. If it ever goes over 4.25V, it should go in the garbage.Now some chargers can do a pre-conditioning. When the initial float voltage of the cell is too low (to the point of damage), it will do a very small "trickle" charge of low current for awhile, until a minimum voltage is reached before opening the flood gates.

author: kingofkya
author_rank: Regular Contributor
timestamp: November 10, 2015, 12:31:22 am
content: Quote from: rsjsouza on October 13, 2015, 07:36:23 pmI have that same 4 battery charger works really well. Resurrected a few cells that would not change on my ebay non name charger.

author: HKJ
author_rank: Super Contributor
timestamp: November 10, 2015, 06:58:57 am
content: You can find technical reviews of many LiIon chargers here:http://www.lygte-info.dk/info/indexBatteriesAndChargers%20UK.htmlXtar makes very good chargers, for cheaper chargers Nitecore has some good models.

author: SteveLy
author_rank: Regular Contributor
timestamp: November 10, 2015, 02:42:38 pm
content: Quote from: Lotus on November 10, 2015, 12:05:25 amThe charge current of the i4 is 0.375A per cell for four cells, or 0.75A per cell for two cells (in neighbouring slots). So depending on the capacity of the cells, it may take up to about 10 hours for the highest capacity 18650s available today. If it's taking 24 hours, something is wrong with the cells or the charger.

author: bitslice
author_rank: Frequent Contributor
timestamp: November 10, 2015, 03:05:45 pm
content: One of those Chinese CV/CC circuit boards and a battery holder, one for each battery.Then at least you know what you are getting and it will be cheaper.

author: bitslice
author_rank: Frequent Contributor
timestamp: November 10, 2015, 03:28:38 pm
content: Quote from: blueskull on November 10, 2015, 03:18:29 pmMy bad, I meant the ones with say a TP4056 chip on boardthey have temp sense, charge termination, charge rate set, auto recharge, status leds etc.this kind of thing:http://www.ebay.co.uk/itm/TP4056-Lithium-Cell-Charger-Module-with-Battery-Protection-UK-stock-/161862573162

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 08:37:52 pm
content: QuoteNo, it doesn't. There are a lot of charging ICs that do not do these things. And logic should tell you that the CV part of the charger makes these things redundant.Some charger IC's have a shutoff when current drops below, say a few mA. This is touted as a safety feature. It is not. It is simply so the IC has a discrete place to switch the STATUS pin to show when the cell is fully charged, because it's convenient. Technically the current never completely stops, due to self-discharge. You have to call it at some point. Call it a safety feature, sure why not. But for all intents and purposes, current stops moving into the cell when the cell reaches the CV.Heck, some chargers might only charge at 0.1C, to begin with.See Ohms Law. When Vcharger-Vbat = 0V, current is 0A. CV = 4.2V, and cell reaches 4.2V float voltage. LOL at the very suggestion you need some other way to terminate charging. And double LOL that you would want that to occur with 0.2C current still pouring into the cell at CV of 4.2V. You're off by at least an order of magnitude, and even then it's still nothing close to necessary.If I take an undamaged, fully charged li ion 150mAh cell, set my lab power supply to 30A max @ CV of 4.2V, I can plug in the battery and leave it there indefinitely, and approximately nothing will happen. In my lifetime, anyway.

author: HKJ
author_rank: Super Contributor
timestamp: November 10, 2015, 09:37:01 pm
content: Quote from: KL27x on November 10, 2015, 08:37:52 pmExcept you will wear the cell down. Look in any datasheet for a LiIon cell and you will see a end of charge current.A CC/CV voltage profile has 3 parameters: Charge current, charge voltage and charge termination current.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 10:37:00 pm
content: QuoteI know this. The cutoff occurs before you get too close to the self-discharge rate, otherwise it may never reach the cutoff. Like I said you have to call it somewhere.OTOH, 0.2C of a 2000mAh phone battery is 400mA. That is not even close to done, charging, lol.QuoteFor NiMh, I can't disagree. For li ion, LOL.QuoteCharging to 4.2 or even 4.25V is not overcharging a li ion battery. So I agree with this statement in a void. In the current context, this is another LOL.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 10:48:48 pm
content: I'll put it simply.The reason a charging IC will cutoff voltage at ~0.001C-0.005C is so a little light can come on to tell you that it's done. That is the only practical reason. For marketing purposes, you can call it w/e you want.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 11:00:42 pm
content: If it's about longevity of the battery, ask yourself, what would be the practical difference between CV charging a 2000mAh cell, indefinitely, at 4.199V compared to charging to 4.2V and stopping at a few mA of current?Would the latter charger be 0.1% faster, maybe?If this whole battery lasts significantly longer at 99% charge is real, the charge voltage of a li ion cell would simply be described as 4.1xV, rather than 4.20V. And 4.20V would be described as an overcharge. And CV chargers set to 4.1xV would be dominant.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 11:42:32 pm
content: QuoteTrying to extrapolate from what this particular manufacturer chose to do with a multi-S battery in a HOT environment is simply wild conjecture without any base. Continually keeping the battery topped off in this case would needlessly increase the heat load due to self-discharge/leakage and the charging circuitry, itself. This might be something that is done for the fuel gauge calibration. It may be the multi-S battery pack is being tapped at less than full S for some things, and needs to be rebalanced, periodically. It may be that while the laptop is on, the battery is under dynamic load requirements that make exact CV challenging. There are all kinds of reasons why this "95% hysteresis" has been implemented in this laptop but is not needed in a standalone 1S charger.If it were solely for battery longevity as a function of SoC, the simple solution would be to change the 95% to 100%, and allow a user override to charge the battery to 105.1% before a plane ride.QuoteThere is a nice pretty curve that shows how the current tapers off. This is nothing more than ohms law. If the IC also has an arbitrary cut off at a specified current, this is nothing more than it is. An arbitrary cutoff point.If that point is, say, 5mA, this represents termination at 0.01C on a 500mAh battery. Or 0.05C on a 100mAh battery. Or 0.001C on a 5000mAh battery. It is completely arbitrary.Leaving a cell connected to constant 4.2V does not give it wear and tear. I do it all the time. Have done so for over ten years. When the float voltage reaches the charger voltage, current stops flowing. Who'd a thunk that electricity doesn't flow unless there's a voltage differential? Mind blowing.

author: bianchifan
author_rank: Regular Contributor
timestamp: November 13, 2015, 07:14:37 am
content: For battery packs I'm using an open source based modified IMAX B6 - cheali-charger.For single cells I decided for BT-C3100 V 2.1, although it'S loading up very high, 4.22 V at 4.2 V (4.215 - 4.218 ext.)Another good one without analysing mode should be XTAR Panzer.I didn't choose Nitecore due to slow charging in hurry times, it's a small-current-only charger.All curves you can find at Lygte-info.dk.http://lygte-info.dk/review/Review%20Charger%20Opus%20BT-C3100%20V2.1%20UK.html

author: kripton2035
author_rank: Super Contributor
timestamp: November 13, 2015, 07:48:48 am
content: I'm also a Nitecore d4 user, the model with the lcd display, cheap and works fine till here but I did not make any measurment on itlike you I had a "base" 2 batteries charger that I simply did not trust !

author: onlooker
author_rank: Frequent Contributor
timestamp: November 14, 2015, 02:26:03 pm
content: I know mid range is in the talking. But, if low cost is also of interest, a solution is to buy one or more USB power bank cases. It may not be particularly fast, but it can save you a lot if you want charge many batteries at the same time.One that holds six 18650s is under $3 on eBay. It can charge 1 to 6 batteries in parallel. Usually, it comes with 4 LEDs to indicate the charge status. You may need to cut the part of the case on top of the battery holder for easy access.Actually, the case is so cheap, I plan to repurpose it and utilize the existing power management in the case as the power supply.

author: KL27x
author_rank: Super Contributor
timestamp: November 14, 2015, 09:10:56 pm
content: 3roomlab:I have no problem to believe that. It sounds like a good practice.I have read all about increased wear at higher SoC. Ten years ago. And ten years ago, I even designed a simple microcontroller circuit to autonomously drain li ion cells to about 3.85V for longterm storage. I built a couple of these pcbs... using the Sharpie method! There's a blast from the past. I even stored these carefully titrated cells in the fridge. I also stored some fully charged cells, and years later the float voltage on these fully charged cells was still 4.15+V. Crude testing didn't reveal anything significant. This is no surprise, to me now, because...The li ion cells that I have been actively using for ten years, kept at room temp, and kept fully charged at 4.2V most of the time, (and also charged "improperly" using CC CV without end of charge termination), are still fine, let alone the cells that were prepped for storage in various conditions. So for me, it is not worth the bother to worry. I went thru all that initial trouble because the predominant misinformation at the time was even without being used, at all, a battery might only last 3 years!!!It's not that accelerated death at higher SoC is't necessarily real, nor really important in certain scenarios. I just feel like for me personally, at room temperature, it is not significant. In a higher temperature application, it could be a very significant problem. Or the 30%/90% scheme could be a matter of practicality to eliminate any potential of under/overcharge in a high-S, rapid cycling application. I woudln't know. In a stand alone 1S charger, I don't see the potential for a significant problem, unless maybe it's done in a hi temperature environment. It's a one shot deal, not a high frequency hi heat application, in itself. And you will never leave a cell plugged in, indefinitely, which may occur in a laptop being left plugged in 24/7 for years. You will take it out the battery, eventually, to use it or to charge other batteries.10 years ago, I read all this stuff, and at the time it sounded very important and official and intimidating. Maybe in another 5 or ten years, some of you will be of the same inclination as I.By now, I have used 3-4 different li ion charging IC's in my projects. I made up some proper chargers for use with USB ports, which are within arms reach as we speak. And I still use a lab power supply more often than any "proper" charging solution when I'm at my bench, because I simply do not care, anymore. It works the same - for me. I set it and leave the battery connected without any care, probably until the next time I need it or the PSU.AFAIC, li ion batteries last as long as I will ever care about when used properly. And CV CC charging without termination is fine and proper AFAIC. They last so long, they are essentially the death of the rechargeable replacement battery market. I learned that in most cases it was easier to simply hardwire the battery into the project and add a recharging port, rather than to have a user-replaceable, externally charged setup. This hard-wired setup is increasingly common in the consumer market.In 10 years, 95% of batteries I have replaced were obviously damaged by human error. Summation of damage: Mostly in applications where I did not install a low voltage cutout, esp in circuitry where I did not install low current sleep modes and forgot to charge them periodically. Other batteries I damaged when I got a cheap lab supply where the voltage started to drift, then went back to my own DIY PSU. And when I finally got my latest lab supply, I didn't realize it drained the load when you turned the supply off, and I damaged another battery I had to replace (weird feeling, because it had been years since I had to do this).Li ion batteries can easily exceed the product life cycle of many of the products they are powering, several times over. So when the battery on my Kindle dies in 6 months, I know it is because some compromises were made.If you are careful in your own designs/usage, you may find the same thing. Some of these considerations are critical and some aren't. You may find out that some things which you thought were important are really not what is making the difference.If you think you need to jump through a bunch of hoops in order to use a li ion battery, it's because that's what the industry wants you to think. It is child's play.I'm not simply guessing in the dark or flying by the seat of my pants. Back in the day, I took this li ion voodoo as seriously as anyone! Here's my first battery de-charger. Sharpie, mechanical relay, linear regulators... Good grief! This probably took me 3 weeks to make! If I found this circuit to actually be of any use, I would redo it today in a quarter the pcb, in one afternoon.... and it would probably run on a li ion battery!Haha, look at the LM339 quad comparator. I only needed 1, so cut it in half!

author: amyk
author_rank: Super Contributor
timestamp: November 15, 2015, 03:21:48 pm
content: Quote from: KL27x on November 14, 2015, 09:10:56 pmInteresting. This brings to mind the huge discussion on theWikipedia talk page(morehere) where things like battery lifetime and charging/discharging are being debated, with others claiming to havevery oldlion cells that still work. This all reminds me of the light-bulb conspiracy... are lion cells deliberately designed to fail after x cycles now?Very interesting quote from there:Quote

author: KL27x
author_rank: Super Contributor
timestamp: November 15, 2015, 07:41:30 pm
content: I hope the cells themselves, aren't being made to "protect us from even the remotest possibility of deadly fires while we sleep" by automatically shutting themselves off before they are even half used.In one case I purchased a cell phone battery that did not work. 0V on the terminals. Sometimes this is due to the protection circuit detecting too much current being drawn, and it can be "reset" by applying some charge/voltage to the battery to reset it. In this case, no. Rather than return the $3.00 battery, I ripped off the plastic housing on the end and bypassed the protection circuit. The battery, itself, was fine.My oldest cells are pretty close to 20 years old and still ticking just fine. Over 90% of my 18650 cells are actually salvaged from batteries I got out of recycling bins back then, when no one else was messign with these things.* But a lot of my batteries are newer poly lipo's, and they are working great for 5+ years, as well.In most cases of terribly battery life, I suspect it's more to do with the application/implementation. And they are not ALL made badly. I still use a digital camera from the year 2001, and it works fine on the original li ion battery.*nowadays, more people have caught on, and I think there's even a market for salvaged cells.

author: SteveLy
author_rank: Regular Contributor
timestamp: February 04, 2016, 01:57:03 am
content: Since I recommended the Nitecore i4, FYI:My Nitecore i4 just blew up in my hand with a bang and flash of light upon being plugged in. This is after just under 6 months of use. There are some loose bits of whatever blew up rattling around inside the unit, which is now completely non-functional.I'll try to get it replaced under warranty but if that proves too hard, I'll get something more capable, an Opus or maybe Xtar.ps. There are fake Nitecore products out there but I did check this one immediately after receiving it new, using Nitecore's "validation" page:http://charger.nitecore.com/validationand it came up as authentic with the validation code first being entered by me. (Fake ones still have validation codes, but they show up as having been checked multiple times already.)

author: djQUAN
author_rank: Frequent Contributor
timestamp: February 04, 2016, 06:15:36 pm
content: Mine also failed but it still worked running on DC input. Been using it on DC ever since and still works fine, so far.http://laserpointerforums.com/f52/nitecore-i4-i2-charger-teardown-update-p2-83155-3.html

author: SteveLy
author_rank: Regular Contributor
timestamp: February 06, 2016, 12:12:09 pm
content: Thanks for that tip, djQUAN. I'll try that once I've pulled it apart and removed the loose bits rattling around inside.

author: SteveLy
author_rank: Regular Contributor
timestamp: February 06, 2016, 03:04:08 pm
content: Thanks again, yep it works with a 12V DC 3.75A adapter (needs 1A), with plug tip positive (polarity not indicated on the exterior of the unit itself).The component that obviously blew appears to have been a fuse. On the board it's labelled "250V 1A". It's a through-hole soldered fuse though (no fuse holder) and I have no replacement handy. It really blew good, to smithereens: a fine dust of metallic and glass particles.