Help, my line trimmer wont....?

Question

hold a charge. it only lasts for about 15 minutes before the battery dies. ive let it charge for several days and it still keeps dying. its a black&decker if that helps. what can i do to fix it? are there any kind of unlikely causes for this?

Answer 1

YOUR POWER SOURCE IS DYING,REPLCE IT(PWR SORCE) DON'T MATTER HOW LONG YOU LET IT CHARGE,IT WILL TELL YOU ITS READY,BUT ITS LYING TO YOU.BUY A NEW BATT.THATS THE WAY IT GOS W/BATT OPERATED TOOLS.

Answer 2

If it has a NiCad battery you are out of luck. Nicads develop a memory when used and charged. If you had used it for 15 minutes then charged it after each use it will only charge up and last 15 minutes. It's always best to completely drain the battery before placing it back on charger

Answer 3

NiCad batteries used to have a "memory effect" but that is no longer as much of an issue.  The origin of this idea came from a report NASA published DECADES ago, when NiCads were very new and the battery companies hadn't improved their processes.  

Of course nowadays, NiCads aren't being designed into very many products, so soon it may be a moot point.  

My best guess is that your trimmer might have a defective battery in the pack - because they usually put several cells in series, if one of the cells goes bad, it's like a weak link in a chain, the whole battery pack will be rendered unusable.     I've done "surgery" on packs to replace bad cells, but in most cases, the packs were fairly old and soon another cell would give out, etc, etc.  

Rechargeable batteries don't last forever - most have a limit on how many times they can be charged and discharged, typically the count is in the hundreds (100, 200 or so).    So it's entirely likely that you simply need to replace the battery pack.   If it's a new unit, that would/should be covered by the warranty.