Nice looking charger. Well done

The user guide says that the quick test feature must be used on fully charged batteries and that the milliohm value can vary by as much as 20% due to slight variations in how the battery is placed in the charger. m.media-amazon.com/images/I/51TCfcbvBaL.pdf

I got a btc-3100 v2.2 maybe a year ago now. If you do a test cycle on 4x Li-Ion batteries at 500ma you'll get the fan to come on and you'll wish you hadn't. I found there was another level of thermal protection that would cycle the discharge on and off. I found a replacement base that accepts a 80x15mm fan on thingiverse and 3D printed it. Muuuuuch quieter. (Important because I am testing cells of unknown quality so I only test when I'm in the room.)

@DavidWatts

5 жыл бұрын

Interesting, I will see how annoying it is. I will only keep one of the chargers and the other will be given away.

That quick test feature would be nice if it actually produced repeatable results. One thing though is that the contact resistance from the terminals can effect the results on that as well, none of those batteries looked like they were seating in there very well, you could wiggle them around quiet a bit. Looks like a decent charger though, might get one to replace my VC2 Plus as I need more banks, but there seems to be a lot of these multibay chargers coming out now.

@DavidWatts

5 жыл бұрын

I have another charger to check out this week, the BT-C3100 seems great but my opinion may change. The quick test thing is a little odd, I couldn't get repeatable results so there is no way to know what it means.

Hi. Nice video. Do you suggest this chicken? As far as I learned after many hours of searching this is one of the best chargers on the market. I'll mainly use it for charging 18650 3500 mah, 14500 750 mah Li-ion, eneloop aaa 750 mah ve eneloop aa 1900 mah Ni-MH batteries, discharging them for maintaining (don't know whether I need it), learning how much energy inside them and their how much life span left and other issues which I don't know. Because I don't enough have knowledge on the subject, batteries. Is it possible to do this with this machine?

I just got this charger in the mail. Do you know if they changed this one to make the discharge cutoff voltage to 3.1? Mine seems to only discharge to 3.1v when testing. I know the v3.1 and the 3400 cutoff at 3.1 now but didn't know the new 2.2 does as well. Everything I can find says v2.2 goes down to 2.8

Mines been in daily use for two years and it's been fine. I'm not entirely sure what the input voltage tolerance is but it seems OK up to 14.5v direct from my solar system.

@DavidWatts

5 жыл бұрын

Good to know, I have a 15v 5A power supply, might have a google and see if that would be ok.

On quick test you should squeeze the battery terminals together while doing the test to ensure a good contact. This is because the batteries own connections will in themselves contribute a high resistance in relation to the the battery’s internal resistance .

@0202fabrice

4 жыл бұрын

I find pulling back the sliding terminal a little bit, then letting it snap onto the battery terminal gives the lowest IR measurement. Sometimes do it 2 or 3 times. That sliding negative terminal can' be directly attached, electrically, to the internal circuit; I suspect that's a bigger factor to the variability than the battery.

@2010stoof

4 жыл бұрын

Manual says to subtract 30milliohm from reading because the contacts add that much resistance.

my mate has a previous version of this which he swears by. i was just looking for the equivellent new model and this seems to be it. i'm ordering one today.

I mentioned this on another vid of yours, the reported discharge capacity on these is ~10-15% high. You can see this for yourself by testing a good new low IR cell, the discharge capacity will be higher than the charge capacity, I've had good Panasonic cells report 200-300mah more out than in! Which is ofcourse, impossible. Also, discharging more than 3A at a time(ie, 4 cells at 1A or 2 cells at 2A) the discharge will be interrupted so the unit can cool down, greatly extending the discharge time. Some people have modified these with bigger fans. There's even 3D files out there for a replacement case bottom that takes a pc fan, I think it's on thingiverse somewhere. The good news is these units are consistent, consistently wrong, but still consistent, so for comparative purposes it's still ok, just don't compare capacities with those from any other unit.

@DavidWatts

5 жыл бұрын

I would generally go with the charge capacity for rechargeables but discharge for the single use batteries I wanted to test, I will have to take this into consideration. Thanks for the heads up!

@SimoWill75

5 жыл бұрын

@@DavidWatts forgot to mention, rather than print a new case bottom, I just got a Dremel and opened up all the ventilation slots. I have four of these 3100's sitting side-by-side, raised up at the back on a bit of wood(maybe 40/50mm high) with a single 80mm pc fan at one side blowing through the space under all four units. This has cured my overheating issue. Side benefit, it tilts all the units so the screens are easier to read when seated at the bench.

@SimoWill75

5 жыл бұрын

One more thing (sorry!) Only other issue I've had is the sliding cell tabs bending slightly over time after many, many cell insertions. If you find you can't get a decent connection, this will be the culprit. Just give the tab a gentle bend forward and all will be good again. I've tested many thousands of cells, so you might not see the issue, but just so you know....

David. Your handy, why don't you break open then wallwert and add a proper AC wallplug?

@DavidWatts

5 жыл бұрын

I really just need to buy a set of adaptors buy I cannot find one locally. Need to get myself down to the pound shop.

I use the BT-C3100, great little charger! Mine sparks when I plug the EU power block into it... a tiny little arc... always worried me, is that normal?!!!! 😂

@DavidWatts

5 жыл бұрын

Ha ha the spark tells you it's working. Totally normal.

@JWH3

5 жыл бұрын

Most switch mode power supplies capable of more than a couple amps will arc when plugged in. It's their input caps charging.

@DavidWatts

5 жыл бұрын

@@JWH3 See, Jake agrees. The bigger the spark the more it is working ;-)

@ChunkySteveo

5 жыл бұрын

I'll go with that then!! Nice and sparky!

after 2 years mine screen is dead do u have any issues ?

When are my AA rechargeable batteries junk? What reading will I see in the display?

@BASSstarlet

3 жыл бұрын

A simple answer is when the capacity would be a lot lower than the specifications of the battery.

The rate may vary when changing between CC and CV on LION cells and it will sample the impedance every now and again. I thought 500mah was a lot for a 750mah cell. The temperature will be lower and battery cycle count higher if it is charged a little more gently. Half C is about right I think. I don't know how effective the refresh feature will be. I know that SLA battery's can be rescued using pulsed AC. I would love to know if it does anything aside from just multiple cycle's. Surely you are decreasing the lifespan of the cell. It would be interesting to monitor the charging voltage with a scope hooked up to see if it is doing anything strange. Its a shame it cant use the discharge to top up the charging cells instead of chucking it away with a resistor of mosfet on a heatsink !

@Brian_Of_Melbourne

3 жыл бұрын

More like one tenth of C so 70 mA for the 700 mAh cell and 45 mA for the 450 mAh cell. You should probably be clearer about mA vs mAh (current vs capacity). They are NOT the same thing so saying "...pulled out eight milliamps" leads others astray, it's eight milliamp hours. Then you quote the charging current as "two hundred milliamp hours".... When you said you didn't know much about this sort of thing I wasn't actually expecting it to be true. Gave up half way through.

@TRS-Tech

3 жыл бұрын

@@Brian_Of_Melbourne I wasn't awake by the looks of it. He does mix up capacity, current and as you note the numbers are wrong anyway. It does appear he is reading the internal resistance as capacity and visa/versa. Its been a while but if I remember correctly NIMH cells gas internally when charged to full and the electrolyte re-condenses presenting the losses as heat. I know that cell temperature was used by many chargers to know when to terminate the charge. I wonder when he talks about cell cycles he is thinking of the old NICAD chemistry and memory effect ? The poster is never going to get the same AH or WH he puts in back out again. If he does I want to own some of those 100% efficient cells myself.... It may also be that his strange readings are down to the power supply not being up to the job voltage or current wise. We all take these cells (especially LION) for granted but the engineering and chemistry used in making them is incredible really and we are really still in the dark ages energy density wise. I think lithium ion and super capacitor hybrid cells are going to be the next big thing. The surface area they can create inside those super caps is incredible ! After all time scale wise iy wasn't that long ago they were experimenting with leyden jars !!!!!!

"Use Provided AC/DC Adapter Only!" :)

@jameshauser1507

5 жыл бұрын

He would but it can't plug it in its a european-style

How do you know when a battery is finished charging?

@DavidWatts

Жыл бұрын

It'll say FULL on the display

IR test is confirmed garbage on these(and pretty much any other tester) A more reliable indicator of battery health is Round Trip Efficiency, that is, how much you get out divided by how much you put in. Eg: cell took 2000mah charge and you got 1800mah discharge, so 1800/2000 = 0.9 = 90% RTE. Lower IR = higher efficiency. With this unit and very healthy cells, you can get higher than 100% RTE, see my other comment about the problem this unit has with reported discharge capacity.

@kdanagger6894

5 жыл бұрын

Accurate IR Tests are difficult with any kind of standard battery holder. The problem is the contact resistance. You can usually improve the reading somewhat by cleaning the end of the battery with an eraser, etc before testing to remove some of the invisible oxidation that forms there in a fairly short period of time.

11:40 - Because it's made out of Chinesium

Umm... It looks like you can pull out the European plug... it's probably just an adapter.

This video didn't even cover a tiny proportion of the features of this charger! You realise that most people use them for Lithium cells, not NiMH?

@DavidWatts

5 жыл бұрын

I always look forward to your comments. What did I leave out? I spoke about the features and showed the ones that I was personally going to use.

I predict that the “5500mAh” NiMH cell will not even hold 550mAh (10% of the claimed capacity). After all, if you are going to claim an outrageous capacity, why even bother making a AA cell with a respectable capacity (2000mAh+ is respectable for a good quality low self discharge AA NiMH); go big or go home, etc...

@DavidWatts

5 жыл бұрын

I'll check out the next charger next week then I choose the one for the tests and then it is battery showdown time. That 5500mAh battery weighs a tiny amount so you are likely right.

I learned nothing from watcing this.I have this model and just bought some hi mah aaa batteries and want to test how much mah they put out according to what they say on the battery.Why cant anyone just make a simple video showing how to do that.

@DavidWatts

2 жыл бұрын

I think I went through the modes. You need to select the charge test mode. It will charge, discharge and charge the battery showing you how much current was discharged.

I just got mine yesterday and noticed on the box, "Up to 20,000mAH" LOL 20 amps charging capacity? I don't think so.

@0202fabrice

4 жыл бұрын

@Mentorcase: 20,000 mAh is not 20 amps; it's the multiplication of the charge current by the time involved, typically several hours. Charging occurs at voltages only a fraction of the 12 v 3A power source - let's say, 3 v., and with an efficient internal DC to DC converter, approx. (12v/3v)* 3 amps = 12 amps of charge current is possible, in principle. And if typical charge time is, say, 4 hours, that computes to 48,000 mAh.

Your timing for this video is a little wrong because of the problem great scott has with banggood: kzread.info/dash/bejne/o3-bm5qAYpywgbQ.html until that is fixed, i don't look at video's sponsort by them. Nothing to do with you.

@DavidWatts

5 жыл бұрын

Fair enough, I find their behaviour abhorrent too. That is why while linking to their site, since they sent it to me for free, I also put in the description that it was available in lots of online spaces and provided a link to another cheaper provider Aliexpress.