Hoverboard not charging - help needed

[Mammasaid]

My daughter's hoverboard has decided it doesn't doesn't want to charge, it will switch on when plugged in to the mains, but won't keep a charge.

What's the best course of action, new batteries, or let an electrician look at it?

It's got 2 battery packs like this;



and plugging in a multi-meter to the battery terminals gives these readings;





The make and model is this, if it makes any difference?

[cobra kid]

Output from the actual charger?

[.:ian:.]

A 29v lithium pack will be 8S, so 8 cells in series. Lithium cells should not be discharged below about 3v or it can cause damage.
If the cells as a whole are showing less than 24v that's an indication they may be toast.

[BlueFocus]

my son's has had the same a couple of time.

New battery for about £40 fixed it