About a week. But I've probably got the screen displaying a bit too long. There are decent warnings that that battery doesn't have long left, just make sure to include a spare battery in your pump kit.
Also, instead of using the AA batteries that Medtronic supply, use the Energizer Lithium batteries that you can buy in supermarkets. They last significantly longer.
Wow that's not long at all, mine lasts about 3 weeks, I would call Medtronic and ask them if this is a technical issue with the pump, 2-3 days is not good, if there is a technical issue then they should resolve this for you.
Mine lasts for around a week, but it does depend on how often you keep activating the screen, press buttons etc... But also as catapillar suggests, the screen duration could be on to long too.
I agree with @Juicyj , contact Medtronic to let them know of a possible fault. I use the Enlite sensor along with the 640G which is supposed to reduce the battery life even further. I get about a fortnight from Medtronic's batteries and around a month with lithium ones, so it does look like there could be a problem with your daughter's pump.
Bobcurly, have you always had to replace the battery every 2/3 days or has this started recently? A few months ago, my battery suddenly needed replacing very frequently and then I got a "power error" - Medtronic sent a replacement pump. It had something to do with the software so it may be worth calling Medtronic.
Thank you - it has always been like this (only had it a month) but we have also had a problem with the screen whiting out so i think it may be faulty. I.ll give them a call. Thanks
Hey Bob - mine lasted two weeks but since putting the backlight to 30 seconds it's lasted much longer. Also found my 640 lovesss Energizer, and will eat up anything else within days.
My battery lasts 3-4 weeks also. I've had 3 faulty pumps in 6 years, I definitely would get a replacement pump. It's not worth the battery going dead and dealing with what happens afterwards. Best of luck to you.