Clock not holding its time

Archimedes 410/1, RISCOS3, new batteries, clock set but, each time computer is switched on the time (and hence sometimes the date) has gone haywire. I need to reset the time each tiem I switch on.
Anyone any ideas ?

Thanks,
Gary

The new battery is either flat or fitted incorrectly?

Thanks, but tried that, new batteries again – double checked fitting correctly, and the CMOS remembers my SCSI configurations all correctly. Just the flipping clock.
???

It is well known that RiscPC Clocks that have been stopped for months/years often fail to restart. IIRC all Arcs also use a PCF8583 RTC chip the same as in a RiscPC.
Details of our RiscPC Clock replacement:http://www.cjemicros.co.uk/micros/products/rtc.shtml We haven’t tried one in an Arc yet. I’ll try and find a suitable unit soon.