On Mon, Feb 14, 2011 at 3:23 PM, Tony Firshman <[email protected]> wrote:
> Plastic wrote, on 14/Feb/11 20:50 | Feb14: > > On Mon, Feb 14, 2011 at 2:09 PM, Tony Firshman<[email protected]> >> wrote: >> >> >>> >>> On 14 Feb 2011, at 20:01, Plastic<[email protected]> wrote: >>> <snip> >>> >>>> >>>>>>> Is the CR2032 man enough though? >>>>>>> >>>>>>> >>>>>> >>>>>> The CR2032 is 3V 235ma, and on this card would need to be replaced >>>>>> >>>>> every >>> >>>> three years or so, which would be a simple "pop a new one in" >>>>>> >>>>> operation... >>> >>>> The 40LF220 had a lower current capacity but was designed for a long >>>>>> shelf >>>>>> life of ten years, hence the bulk. So yes, the CR2032 truly fits this >>>>>> application. >>>>>> >>>>>> The format is standard for battery backed clocks on PCs, but was quite >>>>>> >>>>> new >>> >>>> in the late 80s. >>>>>> >>>>>> I will look at current costs for getting a batch of 100 of these tiny, >>>>>> single layer PCBs made. >>>>>> >>>>>> Couldn't the card have a battery socket so that only the battery need >>>>>> >>>>> be >>> >>>> replaced? >>>>> >>>>> ( ... and why are you not yet living Texas time - it is 2am (8-)# ) >>>>> >>>> >>>> >>>> That is exactly what I was describing ;) A simple adaptor card to a >>>> >>> CR2032 >>> >>>> socket, and a CR2032 battery. >>>> >>> Ah sorry. >>> 3 years though seems a mite short. I wonder if there is a more beefier >>> battery that is thin enough - or maybe a chargeable one? >>> >>> >> There is, but it has 50% higher capacity and costs $12 instead of $0.99 at >> the supermarket. I said three years as a minimum. It's quite possible that >> it would last 5-6-7 years - I'm just being very conservative. Also, the >> CR2032socket in bulk is under $1, but the socket for the CR2045 is $7.80 >> in >> bulk. >> >> I think people will happily pay $15-20 for a 3-5 year battery change at >> 99p >> than pay $25-$30 for an extra couple of years. Also, changing the CR2032 >> batteries is so easy... 15 seconds, including removing and re-inserting >> the >> card. >> >> Yes - in that case the 2032 makes sense. > It is a pity the PC has stadardised now on the low capacity > non-rechargeable. In the old days they used a Minerva like NiCad pack that > lasted for yonks. > > Tony > Well no, it makes perfect sense. The Gold Card was designed with the expectation that it would still be in use in ten years. Can a typical new PC expect to outlast the battery? Dave _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
