Charger or bike issue?

[LeighPing]

Any ideas about what's going on here then?

 

[Nealh]

Probably the cc/cv charging of the charger fluctuating, voltage shouldn't be seen to be dancing around like that. All my batteries when charging the voltages are static and climbs slowly by 0.1v , some have a mini lcd/battery meter wired permanently to them or some I check sometimes with a DVM left connected.