HP Forum Archive 20

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WP34S: Power consumption Message #1 Posted by exschr on 6 June 2011, 2:59 a.m. Reading about this great repurposing project makes me eager to go buy a 30B and explore a world of nicely put together alltime-best-of functionality in ONE calc! great job done! But I wonder if the 20B/30B hardware is as hard on batteries as is the new HP35S? I'm getting sick of replacing again and again a set of batteries in the HP-35S! This is just not user-friendly! (HP, do you read me?!) I rather have a bigger case with space for fat batteries that last at least two years than having a flat thin calc that eats through three sets of batteries per year I feel like selling this hungry HP-35S-monster and stick to the 15C/16C/41C and enjoy (battery-)life with them. What are your experiences? How long last a set of batteries in the new 20B/30B? Thanks for input, Roger

Re: WP34S: Power consumption Message #2 Posted by Paul Dale on 6 June 2011, 4:56 a.m., in response to message #1 by exschr I'm still on my first set of batteries in the prototypical 34s test unit (okay, Marcus probably has this but mine will be second in line I suspect). I've done lots of coding and testing and it is still fine. Will the batteries last as long as a voyager? No chance -- my 15c is on its second set now. Will they last longer than any LED calculator -- by a huge margin. So, go out and buy a dozen 30b's and repurpose them immediately. The only way HP will take up own design is if people buy lots and lots and lots and lots and even they they won't :-( - Pauli

Re: WP34S: Power consumption Message #3 Posted by Marcus von Cube, Germany on 6 June 2011, 7:17 a.m., in response to message #2 by Paul Dale Pauli, what does BATT tell you on your device? One of my reflashing attempts of my 30b wasn't too smart on my side. I let it sit in SAM-BA mode for an hour or so. When I came back, the batteries were down to 2.7V :-(. Power saving is essential on this type of machine. What I've learned: Two batteries should last much longer than an hour while the machine is busy (or idling in SAM-BA mode with the cable connected.) The cable itself is powered by the calculator, so don't leave it plugged in when it is not in use! There are essentially four modes of operation in the firmware: 1) Full power, while a function is executing or a program is running. 2) Active idle, e. g. during a programmed pause or for about half a second after a key stroke. Interrupts are running in this mode for house keeping tasks. 3) Deep sleep with display on and keyboard active. 4) Off with continuous memory. A fifth mode is possible: Make a backup with ON+STO and then pull the batteries. Approximate power draw from the top of my head: 1) 30 mA (10 mA if battery power is low and speed reduced) 2) 0.4 mA 3) 0.15 mA 4) ? (I couldn't measure it with my equipment) 5) 0 :-) I'd be glad to see measurements by other people more knowledgeable than me.

Re: WP34S: Power consumption Message #4 Posted by Paul Dale on 6 June 2011, 9:10 p.m., in response to message #3 by Marcus von Cube, Germany BATT says 2.9 currently. I don't leave the device plugged into the cable for any length of time. Pauli

Re: WP34S: Power consumption Message #5 Posted by Dieter on 6 June 2011, 3:59 p.m., in response to message #1 by exschr Quote: But I wonder if the 20B/30B hardware is as hard on batteries as is the new HP35S? I'm getting sick of replacing again and again a set of batteries in the HP-35S! ... ...a flat thin calc that eats through three sets of batteries per year What? The 35s is hard on batteries? You have to replace them over and over, even three times per year?!? You must be using a different calculator! I got my 35s in August 2007, just as it was available in Europe. The first set of batteries that came with the calculator had to take heavy testing and playing around with the new toy. It lasted for about a year. Both the second and the third battery set powered the 35s for almost one and a half year each (!) while the calculator was still used every day. All in all it was three years and ten months on 3 battery sets, or on average 1 1/4 year per set. I am using regular quality batteries from electronics and photo stores and cannot see that the 35s should be a battery-eating monster. Dieter

Re: WP34S: Power consumption Message #6 Posted by Raymond Del Tondo on 6 June 2011, 7:34 p.m., in response to message #5 by Dieter There was a related thread a while ago. The 35s seems to drain more energy when the unit is off. Also happened with my 35s, whose batts were empty after a year of non-usage. Interesting thing is that the batts of my 17bII+ silver edition are still intact after months of non-usage, so the hardware or software of that model seems to be somewhat more efficient than that of the 35s. Ray

Re: WP34S: Power consumption Message #7 Posted by exschr on 7 June 2011, 4:22 a.m., in response to message #6 by Raymond Del Tondo Quote: ... The 35s seems to drain more energy when the unit is off. ... Sounds irrational but confirms my expirience. Anyway, my 35s seems to drain a lot!

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