When is it flat?

[RobsParticipant @robs46138]

Hi, this has probably been asked before but I have not been on the Forum for a while so I will apologise now for bringing the subject back. Is there a set value that tells if a battery is fully discharged? I have just bought a couple of 9.6v nicad packs on Ebay and a charger from Maplin. In the instructions for the charger it says that the batteries must be fully discharged before recharging so how do I tell if they are discharged? Is there a percentage of full charge to drop to before they need charging? I have a multimeter so checking the voltage is no problem but should they be checked under load or not? Sorry for the many questions but I am not sure what to do for the best. Cheers, Rob

[RobsParticipant @robs46138]

[Colin BishopModerator @colinbishop34627]

The working value for minimum voltage is usually taken as 1 volt per cell so that would be 8 volts on your 8 cell pack. In practice catch it as it dips just under 8 volts.

 

Colin

[Dave MilbournParticipant @davemilbourn48782]

Robs

The voltage MUST be checked under load, even if it’s only a bulb. In point of fact, connecting the battery to a bulb is a pretty safe way to discharge it, but DO connect the DVM across it and watch the volts dropping, as Colin says. 1v per cell is also my working limit.

Works for me.

Dave M

[RobsParticipant @robs46138]

Thanks for the info guys, I really appreciate your help. Cheers, Rob.

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