Cordless battery testing

[winchman]

Just bought a Metabo 18V angle grinder, how can I test the batterys apart from just changing them? One looks to be dead, other two ok?

 

[brightspark]

see which one lasts the longest then u will know check the voltage with a meter when they are fully charged

 

[J1nx]

Be careful discharging just the battery pack if it's a Li-ion version, you can easily damage those cells by over discharge and sometimes the pack will be bricked.

 

[The_Yellow_Ardvark]

If you are friendly with an Emergency light Engineer, they should have a tester to test the batteries inside "E" Lights.

I think it may be suitable for Power Tool batteries.

 

[brightspark]

If you are friendly with an Emergency light Engineer, they should have a tester to test the batteries inside "E" Lights.

I think it may be suitable for Power Tool batteries.

its called cut the power and do a 3 hour test

 

[The_Yellow_Ardvark]

its called cut the power and do a 3 hour test

fftopic: Only if all the lights are rated at 3 hours.

If, like most, bang a new light in, or if customer is tight as a ....... new battery.

 

[Turbo]

Charge the battery fully then take it apart & measure the voltage of each cell. Normally they should be around 1.2v each for nicads, it should be written on the cell. You often find that there are only 1 or 2 bad cells that are stopping the battery pack working. If you replace those you might get it working again, though for the cheap price of new nicads you could replace them all.

If they all measure around 1.2v you need to measure the voltage under load. When I'm testing cordless drills I drive 6x100mm screws into a block of wood while monitoring the voltage of each cell in turn. Not sure how you do that on a grinder - a grinding disc, a lump of steel & firm pressure?

 

[winchman]

Thanks I will have a look at the weekend

 

[Richard.]

Good choice on the metabo grinder. I bought one and it Knocks the spots off the old Milwaukee imho. I bought the snap on one used condition (metabo in red) very cheap about a year ago so that it took the same batteries as my other stuff.
It's the only cordless Grinder I've used that doesn't stall with a bit of a push. I hope it lasts a while as I'd never pay the silly new price for it I'd just cop the different battery platform and buy a metabo.