Test/Review of Charger Skilhunt M4D

POK based on wha HKJ said you might either have a defective charger or a bad battery.

Did the charger do the same thing with the other battery when it completed charging?

I din’t test more yet, maybe protect PCB batteries problem.

I've discovered this charger on your website HKJ, it seems to be very good for all batteries, perhaps the best critics you have written.

I was surprised with the unique button but finally, it seems that's not boring. Does it choice automatically the current for the chemistry? Or does it push the lower one? What is the interest to choice LiFePO4 for all slots?

Thank you HKJ, good job .

The single button is easy to use, but a bit slow when you want to select 1A charge current.
The charger do always start at the 300mA setting when powered on, changing batteries will not change current.

I am not sure what your question is.

For my 2nd question, I don't know very well LiFePO4 but I've thought they have not the maximum charge from the other Li-ion batteries, 4.1 V perhaps instead of 4.2 V?

I've seen the Skilhunt can't do any discharge or refresh . Nothing is perfect . Then I'm wondering if I buy it or no.

I don't understand why I don't receive notifications for response while it seems to be good in my dashboard .

LiFePO4 is 3.6 volt maximum when charging and will usual drop 0.1 to 0.2 volt when the charging stops.

Correct, it is not a analyzing charger.

Because BLF has just been moved to a new server and configuration is not finished yet [07-MAR-2016] Current status of BLF upgrade process

Ok for LiFePO4, that's why it's necessary to configure specifically the charger.

Have you in memory a 4 channel charger with dashboard display which is good and complete? I read your website regularly but I don't remember I've see one .

Ok for the forum. As I'm not easy in English, I don't come often on the forum and I only try to read the subjects which interest me.

Some questions HKJ, I can send you private messages but it can interest other guys : On your website, is it possible you write the date of the chargers tests on the main page? Thus we can find quickly the latest additions .

I've red a Li-ion battery doesn't be discharged under 3 ~3.1 V and charged above 4.2 V but on this test, you said that you wish the charger goes over 4.2 V. On Fasttech website, in batteries specifications, we can see batteries whose lower charge is 2.5 V and upper charge is 4.35 V. Are they more efficient or is it dangerous for the batteries?

Thank you .

Check the SkyRC MC3000, but it is rather expensive.

On my website everything is listen in chronological sequence, you can also look at the “Last additions” on the front page, it list all my reviews for about the last month (Again chronological).

The voltage some people says are only guidelines and often misleading. The low voltage from a LiIon battery is very depend on load, taking a battery out of the equipment and measuring with a DMM is unloaded voltage and can be more than 0.5 above loaded voltage, when battery is close to empty!

Most regular LiIon batteries has a upper limit of 4.20 volt, but some special types are made to handle higher voltage (4.30 volt and 4.35 volt). Before charging to these voltage you must now that the cell is designed for it!

I've begun to read the test of the SkyRC but I've stopped because it seems to be complex with a lot of possibilities and the test is very very long (as I said, I'm not easy in English). I try to maintain as well as possible my batteries but I have many other hobbies .

Ok for the chronology, I've noticed that the last ones are on top (but we don't know when you did them).

Sorry, can you explain? I don't understand.

Do you think that Fasttech specifications come from the manufacturer and thus are true? For example :

https://www.fasttech.com/products/1420/10001980/2204400-authentic-panasonic-ncr18650b-3-7v-3400mah

And I've seen that these batteries have the same reference but are not same :

https://www.fasttech.com/products/1420/10001980/2204400-authentic-panasonic-ncr18650b-3-7v-3400mah

https://www.fasttech.com/products/1420/10001980/2741006

It's a little disturbing.

You do not need a super smart analyzing charger to use batteries.

Battery charger reviews are done once a week (I wonder how long I can continue with that, before I run out of chargers).

When somebody says minimum safe voltage is 3.6 volt, they do not say how they measured that. When the battery is in a turned on flashlight 3.0 volt is safe (And often also lower values). When you take the cell out and measure it, the voltage may be 3.6 volt for the same battery that was 3.0 volt in the light.
In this article I measure some voltages with and without load: Battery charge percent

Fasttech just copy the specifications they get from their supplier and not all supplier are careful with the specifications. (Panasonic do not supply batteries directly to Fasttech or any other outlet for loose cells).

Yes I want a charger that charges as well as possible different batteries, refresh Nixx batteries and incidentally can say me what is the battery capacity. Thus it must have a discharge capability and this Skilhunt haven't.

There are a lot of charger brands, then I think there is regularly new models. Perhaps you will be tired before the stock will be exhausted .

I thought minimum and maximum charges were done with the battery out of the lamp.

With the same lamp charger, the first Ultrafire I got are stopped at 4.2 V (measured out of the charger) and the new ones stopped at 4.35 V (out of the charger), which was surprising and perhaps annoying.

With the first lamp I bought 4 years ago, the lamp stops when the battery have 3 or 3.1 V (I don't remember exactly, and measured out of the charger) and with the new lamp, the batteries were at 2.85 V (measured out of the charger) and have not stopped. I didn't try to know where it can go down.

LiitoKala Lii-500 or Opus BT C3100 are the usual choices, they handle all the common batteries.

The selection get a bit limited when I ignore chargers that looks the same and expensive charger and I must be able to buy them without paying a high shipping fee (last from a US dealer was $50 for shipping).
The above restrictions do not apply when somebody give me chargers to review :smiley:

No normal LiIon is supposed to go above 4.25 volt (But it might be a good idea to replace the battery in your DMM).

3 or 3.1 volt do not really match anything, if it had been 3.3 to 3.6 volt if would probably be LiFePO4

Ok I've red the capacity test and if I understand the first graphic (discharge test), for the other...

For the second, does it means the battery lost ~0.5 V in 25 hours when the battery is out of a lamp or a charger?

For the graphics with "With load, 10 s, 30 s... 60 mn", I don't understand at all. Is the red curve represents the charge when you measure the voltage immediately after you stop the flashlight and 60 mn the voltage after 60 mn of rest (battery out of the lamp during 60 mn)?

I suppose the DMM is a voltmeter. I've done the tests the same days for the "old" batteries and the new ones. I don't think it have a problem and the screen display is good.

For the LiitoKala Lii-500, you said it doesn't charge completely the Nimh, ~15% are not filled (for example 2100 instead of 2450). It's bad .

For the Opus, you said :

" the peak charge and discharge current for LiIon are a bit high"

Perhaps I have to buy the first one for Li-ion and the second for NimH, or the Skilhunt for charging and one of the 2 others for refresh and analyzing .

I've seen on Gearbest, there is an Opus v2.2. Perhaps, it's better.

http://www.gearbest.com/chargers/pp_173012.html

Yes sometimes, I bought in USA and the last time, the vendor asked 84 $ for shipping a motorbike saddle . It was more expensive than the saddle. If you buy all the products you test, it would cost a lot. Are you a little mad or a fanatic charger lover ?

On Fasstech specifications, some few batteries have a ceiling of 4.35 V as the Panasonic of the first link I gave you.

I have a headache with all this English, it's exhausting .

The second curve is exactly the same as the first, I just uses a time scale instead of a Ah scale. In both cases I am discharging the battery in pulses of 0.1Ah.

The time is how long I wait before measuring the voltage, after I have removed the load. The red curve is measured while the battery is loaded, the other some time after the load is removed (I do not use a flashlight, but some fancy computer controlled measuring equipment).

DMM is “Digital Multi Meter”, i.e. a voltmeter. Usual a cheap voltmeter will show too high value when the battery is nearly empty. This means it is always a good idea to try a new battery in the DMM when a value is higher than expected.

Most people will barely notice this in practical usage.

This is mostly an issue with smaller cells, for 18650 it is not important.

I do not buy everything, I do also get a lot from manufacturers and/or dealers. A lot of the people that add contents to forums can be called a little mad, it requires time and dedication and you do not really get anything for it, except the pleasure of doing it.

The NCR18650B is a 4.20 volt cell according to the Panasonic datasheet, but somebody has published the wrong 4.35V specification from the start (When possible I check the manufacturers datasheet for cells).

I bought my multimeter in Otelo in France (http://www.otelo.fr/fr/index.html). It's a specialist which sell equipment for industry. I buy in this shop tools for my milling and my lathe. It's not a very powerful device but I think it's serious .

Ok I didn't understand because there is 1 A on the title of the board and 25 h x 1 A is not possible. Then I don't know what is 1 A.

What do you call "the load"? For me, we load the battery in the charger. Ok, when you stop to use the flashlight and removed the battery, the voltage climb a little and this elevation is more important if you wait more.

In the lamp I bough a few weeks ago, the light became low and when I removed the batteries, there were at 2.85 V. I tried to charge them with the lamp charger but it doesn't work and the voltage falls to 0.3 V !!! After a few days it climbed to 1.8 V. I loaded them to 4.35 V . I think it's time to buy a good charger.

Ok, but I think 350 mA is too important. 5% why not, 15 % no.

Ok and it would be interesting you can test the new version 2.2 .

Ok, thank you very much for your job .

To discharge 0.1Ah I discharge with 1A for 6 minutes (1/10 hour)

A load is anything that uses power from the battery. This has nothing with loading the charger to do.

The differences are very small and because of that I do not really see a reason to do 3-4 week testing on the updated version.

Ok for “to load”, in French, it’s not the same meaning.

When the manufacturer modifies a charger, he says you exactly what he have corrected? And for the Opus, it’s not really interesting?

Usual not, but this time it was posted what the change was.

Ok, thank you HKJ .