We have a Dali system, i understand the requirements when it comes to PPM monthly/Annual 3 hour discharge etc...

QUESTION—At the point of completing a monthly test, how do you get assurances that all the batteries will discharge for a minimum of 3 hours? The annual PPM dictates a 3-hour discharge, and any that fail that test are replaced with new batteries that are then charged up. Over the 12 months, the batteries degrade. Should a battery always last a minimum of 3 hours?

Can anybody point me to any guidance that is clear on this point?

thanks,

Jim

 

 

You don't - that's not the point of the monthly test. The annual test is considered adequate based on current battery & charger technology as fittings should not deteriorate significantly enough in a year to be a significant risk. Any 3 hour fitting should last for it's rated duration, there used to be 1 hour fittings for environments that only require 1 hour escape lighting, but these haven't been available for several decades.

Should the batteries always last the 3 hour duration?

That's what they are rated for!