Question Regarding Li-ION battery replacement

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Hi All,

I got from a friend of mine a toy RC boat. looks rather simple, nothing of a well known brand ( not that I know any), it is completely new, but it does not work (no warranty however as this was bought long time ago).

I don't know what's wrong with it - RC Remote control seems to blink when I turn it on, and batteries charger lights up when I put it in the electricity.
However when I connect the battery inside its case in the toy boat, the boat does not react to the remote control.

My first assumption is that maybe the 7.4v Li-ION battery is not good (attached a photo). it is also the easiest assumption as batteries are something that i can find online...
I researched a bit online it is seems the connecter is EL-2P.
I looked up on Amazon / Ali express / Banggood for 7.4v Li ION battery with EL-2P connector with no luck, could not find something exactly the same,
which leads me to ask:

1. As long as I keep the same 7.4 voltage and similar battery dimensions, Is it ok if I use different kind of battery? like LI-PO or Ni-CD? I expect this will be OK but I will only need a different charger?

2. If I take lower/ higher mAh battery - this only affects play time till battery depletes?

Of course if you have alternative ways to test for why the boat is not working, i'd happy to hear them
but given I don't have any electrical tools as voltmeter/amperemeter, I figures the most economical way to check if this toy RC boat can be saved, is just buying the cheapest suitable battery for it.

Thanks in advance for any advice :)

If the battery is still taking a charge then that's not your problem... use a voltmeter to confirm the battery reads 8.4V to indicate a full charge... if not at 8.4V then the battery needs replacement.

Are you getting steering response? If so, then check the motor by applying voltage directly to the motor to confirm if it works to determine if the motor is bad or the ESC is bad. If no steering response then it can be either the ESC or Rx at that point.

Try recalibrating the ESC, if that doesn't work then try re-binding the Tx to the Rx.

Worst case scenario, start replacing all the electronics 1 at at time until you figure out the issue with the following order of operations:

1) Motor
2) ESC
3) Rx

There's no sure fire way to say definitively what is wrong, you have to troubleshoot and make your best guess.

Good Luck!
The battery leads can be cutoff and resoldered on new battery the 14500 is actual cell in its demensions.Lower mah will also give you less amps. not sure what boat this is.but a few pictures always help...more than likely its a all in 1 control unit. than receiver esc and servo control.
1.what boat is this?
2 is it serviceable ?
Hi All

thank you for your comments.

I am not sure that the battery is recharging but when I connect it to the USB charger it has, the light on the USB charger turns on.
but actually now I saw it turns on no matter if the battery is plugged to the charger or not.

Are you sure this simple boat even have an ESC? it is mandatory even in the most simple RC toy?

I am not sure what boat it is it, probably some cheap toy brand. there is no logo or any text engraved on it. attached are some pictures.
I am not sure it is serviceable, i did not open all the screws yet, but it seems that even if I will they will allow to remove internal parts and not the cover.
the cover seems to be glued.

also please note I have zero experience in RC toys, I do not have any tools other than some screw drivers, solder (i have never used), and hot glue gun.
and I don't have voltmeter/ amperemeter.

and just question I have been wondering due to the first comment - if I would want to supply voltage - what would I need to generate it at home?
batteries, housing, and two wires? any version that does not require soldering?
(long, long time passed from electronics class...)

WhatsApp Image 2023-07-16 at 19.43.46.jpeg

WhatsApp Image 2023-07-16 at 19.41.44.jpeg

WhatsApp Image 2023-07-16 at 19.41.16.jpeg
I don't see a rudder which suggests the steering is controlled through the twin motors. Probably not any replacement parts available as it's more than likely an all-in-one unit for electronics and probably disposable.

Did you verify the voltage on the battery with a voltmeter?

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