Power supply or Charger?

[Mygeneration]

Hi, I wonder if someone can give me some advice before I go off and buy a charger AND a power supply? I've already bought a new battery and it does the same.
My Spear & Jackson battery strimmer has given good service to date, but now when I connect up to charge the lithium battery, the lights showing the amount of charge come on and the right hand number flashes but it never increases. In other words it's not charging.

Anyone else had this? I'm leaning towards the charger being faulty but other experiences welcome

 

[DirtMechanic]

Little known, but there is a card inside the lithium cells called battery power management or a bpm card. They can go bad, so when you measure the individual cells they are great yet it will not charge or discharge. Isn't progress fun? Believe it or not, the tv repair people are quite good mechanics for battery tools.

 

[Hvacdocgary]

The charger is giving you an error code about the battery. Most likely battery problem.