Cheap Temu Boat Issue (yeah I know)

[SXFoxstar]

Hi, first post in the boat section I think. So I bought a cheap Temu boat as I live by a canal and thought I wanted to try rc boating but don’t have much of a budget and didn’t want to spend money on something I might not enjoy. It arrived and worked for a couple of months. 
 

However now I am going out placing in the water and within about 2 minutes it beeps to indicate either the battery is low or out of range. It definitely isn’t out of range and I have even bought a battery tester to check the boat batteries. 
 

The odd thing is it does it with all three battery packs I have but when I bring it home to take a look it runs fine after switching off and on, but when at the canal it doesn’t last. What on earth can be causing this?

 

e.g. went to the canal, all three batteries started it beeping within 2 minutes of sailing around.

 

Got home 5 minutes later, holding throttle down and it just keeps going, no beeps no issues at all.

 

Any ideas welcome apart from spend more on a new boat 😆

Edited March 23, 2024 by SXFoxstar