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Jun 30, 2015, 02:52 PM
Fan of just about anything RC
SoloProFan's Avatar
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Discussion

USB chargers, all generally bad? Are there cheap, much better alternatives?


Most cheap small quads come bundled with a USB charger. These are usually just basic current limiters, and not real chargers. Still, there are situations where a small charger can be very convenient. So are there any USB chargers that are working well?


WSX Series

This small USB charger comes in different varieties, with 4 ports, 5 ports and 6 ports.






It sets the output of each charge port to about 4.20 volts, so it doesn't overcharge. On my 4 port version there was a little difference between some of the charge ports, with two being 4.21 volts, and the other two 4.23 volts. I must add that I didn't check with a calibrated Fluke, but with a cheap volt-ohm meter. The results are consistent with my B6 charger, when using it's voltage checker.





TP4056 based solutions

For those that like to tinker a little, and have more control over the charge rate, this might be an option. In another thread I was made attentive of this little board, that apparently incorporates a decent charger.



As mentioned earlier, it has the option to set the charge rate, and looks like an interesting alternative, as these boards are very cheap.


Courtesy of S.Giles, here's a link to a Youtube vid explaining more about the TP chip based board:
Charging a Lithium 18650 Cell using the TP4056 (12 min 30 sec)



This vid can also be helpful:

Changing charger for quadcopter (2 min 54 sec)



Attached is a list of R4 values and what charge current these result in



Alert!

Warning TP4056, As we all know nearly everything gets cloned, same goes for the TP4056 chip used on these charger boards and others, You need to do a quick test of the board BEFORE you start using it, The problem is some of the TP4056 chips that are fake do NOT function as they should when in use. To test if you have one of the BAD fake chips, do NOT connect it to a power input or USB supply. Connect your charged battery to the to the output of the PCB, then check for voltage on the input side with volt meter, if it back feeds voltage, do NOT use it, You have a BAD chip. Also if the if any of the LED light up you have a BAD chip.
Most of the fake TP (NanJing Top Power) chips are OK, out of the 50 or so PCBs I have used only 2 was bad and odd chips to the others PCB's that came in the same order.
More info here http://jimlaurwilliams.org/wordpress/?p=4731.
Last edited by SoloProFan; Oct 09, 2015 at 02:22 PM.
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Jun 30, 2015, 04:02 PM
Orlando FL
Dennis S's Avatar
Good idea to start this thread,

Here is my entry , this E-flite USB charger came with my Blade Nano QX 3D, Seems to be a much better charger then those cheap ones included with most toy quads, but you pay for it, at 11 bucks each, buying 4 of these to charge 4 batteries at once will cost you 44 bucks, there are some nice chargers in that price range
Jun 30, 2015, 04:09 PM
Registered User
S.Giles's Avatar
The charger that came with my (Revell re-branded) Hubsan Nano-Quad seemed OK, but there are others that you wouldn't want to use, including the CX-10 and H8 chargers.

As a policy, I avoid them all, after having a Turnigy Nano-Tech 750mAh cell charged to 4.6v (IIRC) by one of them!
Jun 30, 2015, 04:21 PM
Fan of just about anything RC
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Did anyone check the JJ1000 charger? And the X9/X7/X6 series?
Latest blog entry: For the love of the hobby!
Jun 30, 2015, 06:10 PM
Registered User
Quote:
Originally Posted by S.Giles
As a policy, I avoid them all, after having a Turnigy Nano-Tech 750mAh cell charged to 4.6v (IIRC) by one of them!
Yes, that is one of the situations where the stock chargers are dangerous, when you try to charge an unprotected (Turningy Nanotech cells are all unprotected, that i know at least) cell with a stock charger that uses the battery's protection circuit for charge cut-off.

If you have enough soldering skills (doesn't take a lot) to replace the 0603 current set resistor on one of those TP4056 boards, and patch in the battery connector from the original crap charger, you can have a much better charger for a dollar. Less if you order a pack of 10.
Jun 30, 2015, 06:54 PM
Registered User
where do you get the boards and how do you do it? very interested cause I already have batteries getting weak and acting funny cause of the crap provided usb chargers.
Jun 30, 2015, 07:15 PM
Registered User
Multirotor Go's Avatar
Quote:
Originally Posted by SoloProFan
Most cheap small quads come bundled with a USB charger. These are usually just basic current limiters, and not real chargers. Still, there are situations where a small charger can be very convenient. So are there any USB chargers that are working well?

In another thread I was made attentive of this little board, that apparently incorporates a decent charger, which even offers the option to set charge rate:



Looks like an interesting alternative, as these boards are very cheap.
Nice thread can you please copy past the info from the other thread here? I am super interested in this, well many for sure

the only problem for me would be the micro USB is this available as a standard usb?
Jun 30, 2015, 07:22 PM
Registered User
I might be able to crap together a quick construction video for one of these tomorrow, just found a spare H8 stock charger lying around.
Jun 30, 2015, 08:26 PM
Orlando FL
Dennis S's Avatar
Here you go Hobby King has a board with a jumper to charge at 100 or 500 mah, shows out of stock but someone must have them
Jun 30, 2015, 11:47 PM
Fan of just about anything RC
SoloProFan's Avatar
Thread OP
That HobbyKing board seems similar, but it has a single led, and I wonder how it works with the jumper. The other boards need a resistor to be changed to set the value.

Something different, what diameter shrink tube is needed to "pack" something like this, like is done on the bottom one on the picture of the 4 different homemade chargers?
Latest blog entry: For the love of the hobby!
Jul 01, 2015, 12:02 AM
Registered User
Quote:
Originally Posted by King Theodin88
where do you get the boards and how do you do it? very interested cause I already have batteries getting weak and acting funny cause of the crap provided usb chargers.
Bg sells them cheap. Buy ten so that you have spares if this is your first time soldering.
http://www.banggood.com/10Pcs-TP4056...-p-944211.html

Resistors can usually be bought locally, they are quite cheap.

Soldering the smd resistor is the hardest part but it is not as hard as you might think. Youtube does have tutorials on smd soldering, watch them.
Jul 01, 2015, 03:26 AM
Fan of just about anything RC
SoloProFan's Avatar
Thread OP
Added a list of different R4 values and their effect on charge current.

Maybe it's impossible, but what if someone managed to attach a small display and an adjustment pod, allowing to set charge current, instead of having it fixed?
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Jul 01, 2015, 04:34 AM
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S.Giles's Avatar
As I posted in the other thread, this YouTube video tells you everything you need to know about the TP4056 charger chip.
Quote:
Originally Posted by SoloProFan
Added a list of different R4 values and their effect on charge current.

Maybe it's impossible, but what if someone managed to attach a small display and an adjustment pod, allowing to set charge current, instead of having it fixed?
It should be possible to add a switch to change the 'current set' resistor value. A multi-position rotary switch should work nicely. A potentiometer (in series with a 1k2 resistor) may also be an option.

(Edit: This bit is incorrect, see later posts) Related to this though, is the question of to what current to set the charger for a given battery. The video linked to above suggests 1/2C as appropriate. Well a Nihui H8 uses a 150mAh battery which lasts for 5 minutes (at best), which suggests that it draws an average working current of 1.8A (2A, say). Charging the battery at 1/2C would therefore involve a charge current of 1A, which is the maximum current these boards can produce. Using this logic, there is no need for a switch. Someone (ghlargh?) please correct me if my thinking is wrong here.

Quote:
Originally Posted by SoloProFan
That HobbyKing board seems similar, but it has a single led, and I wonder how it works with the jumper. The other boards need a resistor to be changed to set the value.

Something different, what diameter shrink tube is needed to "pack" something like this, like is done on the bottom one on the picture of the 4 different homemade chargers?
Maybe I just missed it, but I couldn't see any TP4056 on that HK board.

I don't know what diameter heat-shrink is needed, but what I used was too small, and I had a struggle to get it to go on there! It should be easy enough to work it out based on the size of the board, though.
Last edited by S.Giles; Jul 01, 2015 at 07:28 AM.
Jul 01, 2015, 05:09 AM
Registered User
I think you misunderstood the C value, it's just the number of mAh the battery holds, but in mA.

A 150mAh battery should therefore be charged at 150-300mA

For clarification: most high current LiPo cells used for RC toys can handle 15-100C discharge, but recommended maximum charge current is usually only 1 or 2C. There are exceptions, but a general rule is to never exceed 1C charge current unless told otherways. The H8 cell is fine with 2C charge though.

And for reference, normal low current LiIon cells like the ones in laptops have charge currents of 0.5 to 1C and discharge currents from 1 to 5C
Last edited by ghlargh; Jul 01, 2015 at 05:15 AM.
Jul 01, 2015, 05:10 AM
Fan of just about anything RC
SoloProFan's Avatar
Thread OP
Most lipos that are used in the smaller quads, are 250 mAh or less, so it will be good to have the option to select a lower charge current than 1A. For cheaper lipo batteries, between 1.5 and 2C is usually their limit if you want to get some cycles out of these.

I also don't see a TP4056 on that HK board, but it does try to look similar. Maybe they've reverse engineered it.

Added the Youtube link to the first posting


Quote:
Originally Posted by ghlargh
I think you misunderstood the C value, it's just the number of mAh the battery holds, but in mA.

A 150mAh battery should therefore be charged at 150-300mA
Actually, to be more precise, the C value is a number that you multiply battery capacity with, to get max charge or discharge current. Say you have the Eflite 150 mAh 45C battery, which is rated to be charged at 3C according to it's label. So it can be charged at 150 mAh x 3 1/h = 450 mA and can be discharged at 150 mAh x 45 1/h = 6750 mA

I usually stay below 2C with charging small cells. One way to check what a cell can handle is to look how fast the voltage rises at the start of the charge. If the LiPo was almost empty, and voltage shoots up straight to 4.10 or higher within a minute, chances are you are going beyond what this battery can handle. But if it goes up just 0.2 or so volt, so when it starts at 3.70, goes to 3.90 within a minute, the battery is most likely very happy with this charge rate.

Based upon this, I for instance charge my X7 at 0.3A, but the H8 Mini battery can handle 0.4A without a real jump in charge voltage. And the X6 likes 0.2A better, etc...
Last edited by SoloProFan; Jul 01, 2015 at 05:20 AM.


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