How to tell if rechargeable batteries are kaput?

[Andreas Lilja]

They're shown as fully charged by my good quality charger, but they won't make my controller turn on. Do I need to charge all of them *fully* and try a battery tester or there's a less cumbersome path? 

[Andreas Lilja]

Rechargeable, not external.

 

Brain fart. 

[thrasher_565]

36 minutes ago, Andreas Lilja said:

Rechargeable, not external.

 

Brain fart. 

whats a battery? i kid test it with your tung

[TetraSky]

Use a multimeter. Heres a video tutorial about how to test them

 

[jimm_eh]

Are you talking about rechargeable AA or AAA type cells (NiMH, nickel metal hydride)?

There's a possibility that the controller is (badly) designed to consider the batteries dead at 1.2V.  That's relatively pooped out for alkalines (though not completely), but is just getting started for NiMH cells (and NiCad, nickel cadmiums, as well).

If so, your cells are fine, but won't run the controller well.

Try running a set of fresh alkalines to make sure the controller works, then use a meter like in TetraSky's video to check the voltage on them once the controller quits.  If they voltage of each cell is around 1.2V or more when "empty", the controller won't like rechargeables.

[Rusty Proto]

I guess another relevant question is, "what model controller are we trying to push with these batteries?" I've seen a few devices that simply won't turn on if fed Ni-Cds or Ni-MHs. Beyond that, i would also consider trying those batteries in other devices, as I've seen batteries themselves do some screwy things.

[trag1c]

Batteries that are damaged/failed can show as fully charged to a charger (or even a proper multimeter like a fluke) but are unable to deliver current. Even battery testers can show batteries as good but if you do a proper load test they fail to deliver any current.

[Roswell]

AA chargers have no real sense of charge capacity. They work on timers and minimal current level readings. 

[TheMcSame]

If they don't hold a charge, don't power anything or if they're damaged is pretty much my rule.

 

I'd check them in another device if not visibly damaged. If they work, it might be your controller that's the issue. If it works in another device with reasonable life, it could be the controller, either, as another user mentioned, the voltages just aren't sitting right for the controller, or the controller is kaput.