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The CityJet5 is normally delivered with 12 Hawker-Oldham RGT 73 Ah (@ 5 hrs) mainainance-free lead acid batteries. Two and two batteries paired up in parallel giving 6 pairs stringed together in series for 72V.

The lifespan of all batteries is limited by how many deep charge-discharge-cycles that may withstand without loosing capacity. Hawker-Oldham specifications says more than 600 deep cycles. From these numbers we should expect at least two years of battery life. My experience indicates that this does not hold in the real life. I bought a brand new set of batteries when I purchased the car in August 1999. During the winter they performed fine, but started to give up in june 2000 after less than 9 months and 300 charge cycles. Replacing the faulty pair I extended the life until november. At that time the capacity was reduced to less than 60% of new batteries and I couldn't make the 32 km I needed for a ordinary day of commuting. It had to charged both at home and at work to be kept running. To the batteries defence it is worth mentioning that most of those 32 km is spent at full speed at the highway climbing about 220 meters in the process. (I live at about 120 meters above sea-level and the Oslo tunnel which I must pass goes down to 45 meters below...). On a normal day the batteries were run down to about 20% charge before recharged.

So I had to replace the entire set. Petter (at Kollega Bil) had mentioned earlier that he probably could obtain a set of slighly used NiCad batteries if I was interrested.

And I was. Read on... 

See also how to obtain the Car-contollers service report.

Updated: 28. May 2002