> I just recently purchased the 1mb SRAM card from surplus technologies. It
> didn't come with any documentation. I have just a few questions.
>
> 1. Is there any type of warning that you get when the battery is low?
No. This is apparently the great risk in using SRAM cards. Speculation
has it that file corruption will occur should the battery die while file
operations are happening...but I don't know that this has been confirmed.
>
> 2. Can you change the battery without losing all of your data?
Yes. Apparently the card's electronics maintains enough charge to allow
a battery change without losing data. I've tested my Newton SRAM card
and found it to retain data at least 2-3 hours without the battery, though
I'm sure manufacturers would recommend no more than 10 minutes to do the
swap.
>
> 3. How long does the battery last?
>
All the cards I've seen recommend replacing it every year. Buy some spare
batteries now in case they are in short supply (or discontinued) in the
future. Since they're lithium batteries, they should have a long shelf life
(I've heard 5 years?). Annual replacement is probably a very conservative
approach, but considering there is no EASY way to check the battery level
and the risk to your data, you may want to err on the side of caution.
Actual battery life probably depends on the amount of disk activity. Since
I back up my whole SRAM card on my notebook's PCMCIA slot using XCOPY fairly
frequently, I guess I could pop the battery out every month or so to test
it at an electronics shop...may be more trouble than it's worth.