Re: reverse polarity
Sounds like they a requiring a battery of given size to maintain a fixed rate of discharge (I) for 20 hours. I being different for each size. I have seen current (Amps) expressed as "I" before (have also seen power density expressed as I & J vectors but that is something completely different)
However I do not feel like spending 130 swiss francs to find the exact specification.
In the US we rate by how many minutes a 12v battery can maintain a 25 amp load without dropping below 10.5v at 80F. Apparently in the EU they rate by the reverse: what load can it maintain for 20 hours (1200 minutes) without dropping below a certain value. Sounds more appropriate for emergency lighting or an RV fridge.
Either way you come out with amp-hours.
Last edited by Padgett; Dec 27, 2013 at 08:57 PM.