Overmax X-Monster 3.0 RC Car - Packet Loading Issues, USB Charger & 850mAh 7.4V Batteries

Hi,
I have a toy like the Overmax X-Monster 3.0 RC car with an attached USB charger and two 850mAh 7.4V packages.


After 2 or 3 charges, the batteries stopped charging. After connecting the package, the charger pulls between 1-2A and after about 2 minutes disconnects the current.
I measured the tensions on the balancer and the entire package:


There is no voltage anywhere close to 7.4V. Could two packages hit the trail?

Measure the voltage between pins 2 and 3. It should be the same as between 1 and 2 or very similar. 1-2 is the first cell, 2-3 the second, 1-3 full package voltage.

Although, based on these measurements, it can be seen that one cell has dropped in each package.
So, dispose of both packages and buy new ones. By the way, think about buying a new charger. The Chinese ones that are added to toy sets are just hopeless and can destroy packages sometimes.

The question is still for you, did you not use the packets for too long until the voltage dropped below 2.5 V per cell? In this case, the package is also destroyed.

There is 0V between pins 2 and 3. Generally I didn't measure while playing, just the car didn't go any further.
Is it possible to check the charger somehow if it is somehow screwed up and destroys the batteries?
Maybe for an attempt to disassemble these two and put together good goals and check?

edit: In package "B" between 2 and 3, however, there is 3.28V.

So it's all clear. Both packages are scrap.
Don't use them any more. Take them to a collection point for accumulators and batteries and buy new ones.
You can check the charger only by measuring the output voltages, but only the measurement while charging a working package will be correct.

I converted two packages into one and it works. We'll see how long.

Not really. The cells in the package should be selected in terms of the closest possible internal resistance and capacity.

Connecting cells from two different packages with varying degrees of wear and unknown internal resistance is one of the worst ideas.

as I wrote at the beginning, both packages were the same and had the same production date. The packages were identical because they were delivered with the toy.

chab wrote:

as I wrote at the beginning, both packages were the same and had the same production date. The packages were identical because they were delivered with the toy.

It does not matter.
Even packages from the same production line may differ.
That is why the selection of cells is carried out, or at least should (as in the case of better brands), selection of cells. "Budget" companies not only often skip this process, which translates into shorter package life, but it also happens that they buy cells rejected from production by other producers.

The selected packages are compatible with each other - for one package. They have similar startup parameters and life cycle.
The two different packages may already be significantly different.

You can see from the measurements you have taken that each cell is different.
Such a package does not come for long and will not be as efficient as the new package.
It can also pose a risk of damaging one of the cells and destroying the packet - either during use or while charging.

chab wrote:

RC Overmax X-Monster 3.0 car with included USB charger and two 850mAh 7.4V packages.

After 2 or 3 charges, the batteries stopped charging. After connecting the package, the charger pulls between 1-2A and after about 2 minutes disconnects the current.

Hi!
Did you check this "charger"?
I am not able to load it with "brand new" packages from the set.
I can see that OVERMAX and WLtoy-e etc. use chargers with 5V input (USB) is probably a "weak link" of this system ...

Have you tried charging these packages with a power supply with a balancer? You write that you connected to a balancer to measure voltages.
I am tempted to charge it with the iMAX
but, although the package seems to be typical ("current" connector and balancer plug) ...
however, the operating philosophy is slightly different because the package is loaded through the ... balancer connector and the current connector - loads - is left free
hence the fear that the pin layout is standard and will not damage the iMAX

Yes, I also checked the original charger. Unfortunately, it cannot be dismantled.
It is able to charge, but there is a problem with it, specifically with the USB port. Something does not touch it, only when the entire charger is connected, it starts to work properly. If the charger socket and USB plug are perfectly aligned, it does not work properly.
The charger has a charging balancer and that's the only way I charged. I do not understand what you want to do, charge via the current connector?

Thanks for the answer!
However, I will give up this "original" charger.
Even if it has a balancer, it cannot handle packets where one cell is clearly weaker
She's not the only one with the rest, the same is true of a simple lipo7.4 charger / balancer from another toy.
Fortunately, I have an imax and it will be safer / healthier to use it.

In fact, I expressed myself imprecisely,
with the "current" connector I named the plug, which I connect the package to the model (two-pin)
When charging with imax, this is the main charging connector and the three-pin plug then goes to the balancer socket.

We'll see if the packages "get up", if not, I wonder if I can advertise them.
The warranty conditions are at least "conservative" from the seller's point of view ...

They won't get up.

Lithium packets discharged below 2.5V per cell are essentially killed.
The seller will not accept the complaint. Charging the battery is the responsibility of the user and is the responsibility of the user. 95% of such complaints are rejected. If you want, try it.

Generally, you have to buy new packages and use only a good charger.

I had the same case and the batteries died very quickly. Maybe you know where to buy new or some cool replacements?

Recommended for batteries - Buzzer Voltage Meter Alarm Lipo 1s - 8s.

Ok, I will keep in mind, however, where can I get such batteries for this car?
The official website is a swamp of zero response to an email

Link

https://rc.susco.pl/p/23/22358/850mah-7-4v-25c-2s-lipo-do-rodeo-110-z-21-akumulatory.html

https://pl.aliexpress.com/item/32722719958.ht...7_shopb766=887_shop_google=887_shop=google=88 743612850714 & crea = pl32722719958 & netw = u & device = c & albpg = 743612850714 & albpd = pl32722719958 & gclid = EAIaIQobChMI1fbNvObk6QIVwoayCh1DDAS7EAQYASABEgwcLed = awdcl_s

Enter the dimensions of the packages.

The price definitely suits me better with alli and I am finally starting to buy it because my son is asking when I will start it. Does it make sense to take two at once or is it better to try first? The size I think will be ok because the ori are 3cm x 5.5cm. Ori charger that could be for this link?

Hi!

Has anyone tried to use larger substitutes for this?
Exactly I mean BATTERY BATTERY WLTOYS 7.4V 2100mAh TAMIYA PLUG or BATTERY BATTERY WLTOYS 7.4V 2600mAh Mini TAMIYA.
Is it safe?
The car works for a short time on the original sets and I wonder if it makes sense to buy larger batteries.
I will be grateful for your response ;)


Kisses