knowing that bike batteries are as expensive as car bats for a fraction of, power, this is what I have done.

charge the battery and take it to a bat shop with test kit and do a CCA check. If the result is more than 20% of the original bat spec, then it is time for a new one.

If the test if good (<10%) then check your charging system.

before you jump on the lithium iron bat band wagon and pay x2~x3 the regular money, do your research: charging of these is different to led acid batteries. Chances are you bike charging system is not optimised for lithium bats!!

lets us know how it ends